# Strainers, Sifters & Salad Spinners: research notes

Date: 2026-10-25. Scope: hand tools that separate food from water, liquid or lumps: colanders (freestanding, over-the-sink, collapsible, mini), rice washing bowls, fine-mesh strainers and sieves of every size including small "tea strainers" sold as general kitchen strainers, conical strainers (chinois and China cap), drum sieves, flour sifters (crank, squeeze and one-hand shaker), and salad and herb spinners. This matches the leaf's own query list in `zamana-expertise/archive/amazon-queries/kitchen-and-dining-amazon-queries.csv` (colander, over the sink colander, collapsible colander, footed colander, sieve, flour sifter, salad spinner, tea strainer, mesh strainer set, chinois strainer, rice washing bowl). Left to siblings, because their query lists carry them: spider strainers and skimmers (`scoops`, though that register's own notes.md disowns them back to `strainers` — flagged below, unresolved), Hawthorne and cocktail strainers (`cocktail-mixing-tools`), pasta pots with strainer inserts (`saucepans`), splatter screens (`cookware-stove-accessories`), reusable coffee filters (`coffee-filters`), funnels (`kitchen-other`), potato ricers and food mills (`mashers`), teapots or pitchers with built-in infusers (Tableware, outside this sub-vertical), loose-leaf tea infusers and steepers — ball, basket, spoon, novelty — (`manual-coffee-tea-prep`, which claims them by name and whose own notes.md says "tea strainers sold as general kitchen strainers go to `strainers`"; this leaf keeps only that boundary case). Also unassigned by any leaf seen so far: sink drain strainers, which the bare "strainer" query returns and which `dish-racks` (Sink Caddies) is the likely owner of — flagged below. One register; the `tool_job` split divides the three families the label bundles.

Quote labels: **verbatim** = the sentence in quotation marks was in raw text I read myself (curl into the scratchpad, then tag stripping or JSON extraction from the page's own data); **fetched excerpt** = the WebFetch tool summarised the page; **search excerpt** = from a search-engine summary only. Every quote below is verbatim: no WebSearch call was available in this run (the session's search budget was already spent by sibling runs), so every source was reached by a known URL or by walking a site's own sitemap, and read as raw text. No search-excerpt claim exists in this file.

## Seed

Seed output, recorded verbatim:

```
=== Example entry (from an unrelated category) ===
category: car-tyres
what this shows: a number that is on every listing and still needs a judgement attached, because experts know it only compares within one manufacturer's range.
[treadwear_grade example entry, as in examples/tyres-treadwear.md]

Judgement that would accompany it:
{
  "claim": "Treadwear grades can be compared across brands as a rough guide but not as a ranking.",
  "confidence": "high",
  "sources_disagree": true,
  "note": "The regulator describes the test as standard. Specialist reviewers say manufacturers calibrate differently. We side with the reviewers because they test the tyres."
}

=== Persona ===
A print production manager, who thinks in what the spec sheet says versus what comes off the line

Ask yourself two things and write the answers under 'Seed' in notes.md:
  1. What is the strainers equivalent of the example above?
  2. What would this persona notice first about strainers that a typical buyer would not?
Keep what survives the data check. Drop the rest.
```

1. **The strainers equivalent of treadwear is the word "fine" in "fine-mesh strainer".** It is on nearly every mesh strainer and it does not compare across brands, or even within one brand. ATK (small strainers): "While many strainers were advertised as having fine mesh, some were finer than others." Rösle is the one brand checked that prints the opening ("Maschenweite"), and its own labels do not line up: its "feinmaschig" 20 cm strainer opens at 0.05 cm, its "Teesieb feinmaschig" at 0.033 cm, its "grobmaschig" at 0.16 cm, and its "Gaze Sieb" sold on "Die extrafeine Maschenweite" opens at 0.11 cm, coarser than the plain "fine" one. RSVP says "very fine mesh" and "Extra fine mesh" on every conical strainer from 3 to 8 in with no number; Küchenprofi says "feine Lochung" and "feinen Maschen" with no number. **Kept** as `mesh_fineness`, defined by what the mesh holds back (the bran test both ATK reviews use) rather than by the label, with a judgement attached.
2. **The print production manager notices the joins and the tolerances first.** What comes off the line is a handle welded or soldered to the rim, a mesh stiff enough to keep its shape, and holes that are or are not as small as "micro-perforated" claims. ATK small strainers: "We found that strainers with welded-on handles had little risk of breaking off when whacked" and the one that failed "looked as though the handle had been soldered, not welded"; ATK fine-mesh: floppy mesh "warped or detached when we suspended a 12-pound mortar"; Reviewed on the LiveFresh "micro-perforated" colander: "some reviews do say that they are a bit large for draining smaller foods like quinoa or rice". **Kept**: `handle_join` (low priority, research-only) and the stiffness and tolerance notes inside `mesh_fineness` and `hole_coverage`. The persona would also notice that capacity is stated in four different units (quarts in RSVP and OXO titles, cups in Reviewed, portions and bowl diameter on Zyliss's own page, basket diameter on strainers); **kept** as a note in `capacity_qt`. **Dropped**: wire gauge or mesh stiffness as its own measured facet. No source gives a number and no brand lists it.

## Sources and what each supports

### Specialist reviewers who test (America's Test Kitchen)

All ATK pages were fetched with curl and the text read from the page's embedded `__NEXT_DATA__` JSON. ATK pages were found through `https://www.americastestkitchen.com/sitemap/reviews.xml` and the articles and how-to sitemaps.

**ATK, The Best Colanders** https://www.americastestkitchen.com/equipment_reviews/2200-colanders
- "The best colanders sit securely in your sink, drain quickly, and contain foods of different sizes without allowing them to slip through their holes."
- "Colanders with holes that were too big allowed small or skinny foods to slip through, while models with clusters of holes and large stretches of unperforated metal drained too slowly."
- "we focused on simple, no-frills stainless-steel models with capacities of 4.5 or 5 quarts, the sizes we found to be most useful for everyday kitchen tasks"
- "colanders made from silicone or plastic tend to get dingy after multiple washes and aren't as stable or durable as those made from stainless steel"
- "previous reviews have taught us to avoid models with innovative features" (collapsible and over-the-sink named in the same sentence).
- "The exact arrangement of the holes didn't matter as much as the size and number, though."
- "Models with bases that were at least 1 inch tall provided enough clearance"; "colanders that had feet instead of ring-shaped bases were less stable"; "Colanders with bowls that were at least 4 inches tall ensured that food never cascaded into the sink"; "bowls that were 3½ inches tall and shorter were ineffective"; feet "just ⅜ inch above the sink".
- Tests: "Drain 1 pound of angel hair pasta cooked in 4 quarts of water"; same for orzo.
- "If you're looking for a tool to rinse rice, strain sauces, or sift ingredients for baking, see our reviews of fine-mesh strainers"
- Supports: hole_coverage, colander_base, capacity, body_material, colander_format judgement. Confidence high.

**ATK, Cooking Pasta? The Colander You Use to Drain It Matters (2022)** https://www.americastestkitchen.com/articles/5641-cooking-pasta-the-colander-you-use-to-drain-it-matters
- "Avoid colanders that have a few big clusters of holes set into solid metal. You might think that the bigger the holes, the better the drainage, but that's not necessarily the case."
- "look for colanders that are covered in tiny perforations ... Water quickly streams through those little holes"
- "When you pour a pot of pasta into a colander or strainer, the noodles stay submerged in boiling hot water for as long as it takes the water to drain away."
- Supports: the bigger-holes judgement. Confidence high.

**ATK, The Best Fine-Mesh Strainers** https://www.americastestkitchen.com/equipment_reviews/1744-fine-mesh-strainers
- "we focused on models with a basket diameter of about 8 inches, the size we think is most useful for home cooks."
- "Very fine mesh also does a better job of holding back any bran when you sift whole-wheat flour"; "we preferred that the mesh be relatively stiff."
- "models with capacities of about 5.5 cups were ideal"; "baskets that had a depth of 3 inches or less" (single source, kept here).
- "All fine-mesh strainers come with a pot hook ... We vastly preferred models with wide, curved hooks"; "Small or Flat Pot Hooks: These made the strainers harder to stabilize"; a 9 in model's "helper handle ... Since this handle was flat, not hooked, it didn't do a great job of stabilizing the unit".
- "Coarser mesh produces coarser, grittier purees"; "The coarse, loose weave of these strainers also let all the bran pass through".
- "Flexible, floppy mesh sometimes deformed ... warped or detached when we suspended a 12-pound mortar"; "Several models had handles or hooks that flew off".
- Ultra-fine winner: "it must be washed by hand; that same fine mesh proved a bit of a nuisance when we had to pick seeds or vegetable bits out of it."
- Care: sift flour then wash "use soap and cold water there, as hot water can gel the starch".
- Tests: "Sift bran from 1 cup of flour".
- Supports: strainer_size, mesh_fineness, pot_hook, trade-off fineness vs cleaning. Confidence high.

**ATK, The Best Small Strainers** https://www.americastestkitchen.com/equipment_reviews/2410-small-strainers
- "small strainers, sometimes known as tea strainers, which are about 3 inches wide and can be used for a variety of small kitchen tasks: straining citrus juice, loose-leaf tea, and cocktails and sifting small amounts of cocoa powder"
- "While many strainers were advertised as having fine mesh, some were finer than others."
- "separated the fine bran from wheat flour (a test of mesh fineness)"
- "A Wide, Rectangular Stabilizing Hook"; "strainers with welded-on handles had little risk of breaking off when whacked"; "the handle had been soldered, not welded".
- "strainers whose baskets were fashioned from ultrafine mesh ... were harder to clean"
- Supports: mesh_fineness judgement, handle_join, strainer_size cup-size, pot_hook. Confidence high.

**ATK, The Best Salad Spinners** https://www.americastestkitchen.com/equipment_reviews/1916-salad-spinners
- "You use a mechanism—such as a crank, plunger, lever, or pull cord—to spin the basket"; "Pressing a brake button on top of each spinner stops the revolutions on demand."
- "a full-size salad spinner with a capacity of about 4 to 5.5 quarts is best for most households"; compact "about half that volume, or about 2.5 quarts"; OXO Little "holds about 2.4 quarts compared to nearly 5 quarts in the larger model".
- "We preferred models with plunger-style spinning mechanisms"; "Models with pull cords and cranks required us to brace the spinners with two hands".
- "Our favorites could hold 1.75 cups of water before baskets' contents began to get wet"; "models holding less than 1 cup of water inevitably got our greens wet again" (single source).
- "The best spinners had brakes that fully stopped the basket's spinning within 1 second" (listed under "Nice to Have").
- Glass and steel bowls: "none of the models we tested with metal or glass bowls worked as well as our longtime winner from OXO, which is made entirely of plastic"; removable spindles "prevented the spinners from reaching high speeds".
- "Our favorite models had patches of soft, grippy silicone at the bases"; "models that were 6 inches tall or shorter" store easier.
- Supports: spinner_drive, capacity, water_clearance, spinner_brake, body_material (spinner bowls). Confidence high.

**ATK, The Best Tea Infusers** https://www.americastestkitchen.com/equipment_reviews/2455-tea-infusers
- "in previous tests we found that basket-style tea infusers performed best; they were large enough to allow tea to fully expand while still containing small particles"
- "The baskets of most of the infusers we tested were made of metal perforated with small holes, which often let small pieces of tea get through. Our favorite was lined with tightly woven mesh"
- "we had a preference for longer baskets ... when we used them in a 16-ounce mug, they sat too high and gave us weak tea."
- Silicone collapsible infuser "did a poor job of containing tea leaves".
- Supports: infuser_style, mesh_fineness on the tea branch. Confidence high.

**ATK, Do I Really Have to Sift My Ingredients? (2023)** https://www.americastestkitchen.com/articles/7781-do-i-have-to-sift-my-ingredients
- "In short, no."; "To sift dry ingredients, just add them to a fine-mesh strainer sitting over a bowl and give it a shake."; "Our recipes rarely call for sifting. But when they do, grab a fine-mesh strainer."
- Supports: the sifter judgement. Confidence high.

**ATK, Do You Need a Chinois?** https://www.americastestkitchen.com/how_tos/6533-do-you-need-a-chinois
- "Most home cooks, however, can get by with a fine-mesh strainer instead of a chinois."; "if you love extra-smooth pureed soups or often make big batches ... a chinois's large capacity makes it worth clearing some space"
- Supports: strainer_size cone value, the chinois judgement. Confidence medium (one source).

**ATK, The Best Way to Rinse Rice** https://www.americastestkitchen.com/how_tos/9250-the-best-way-to-rinse-rice
- "we always remove surface starch by rinsing the raw grains in a fine-mesh strainer under cold running water"; the strainer method "produced notably fluffier, more separate grains" than swishing in a bowl.
- Supports: rice rinsing belongs to the fine-straining answer, not draining. Confidence medium.

### Specialist reviewers who test (second sources)

**Reviewed (USA Today), The Best Salad Spinners, Sharon Franke, updated 12 March 2024** https://www.reviewed.com/cooking/best-right-now/best-salad-spinners
- Zyliss Swift Dry: "you press down on a large lever, which we found easy to do with one hand. It has a large capacity, accommodating 10 cups of lettuce"; OXO Steel "will hold about 12 cups".
- Pull cord: "it's more work than pushing a lever or button or turning a hand crank, and one hand has to keep the bowl steady as you yank."
- "none of the products spun off 100 percent of the water"
- Brake: "We didn't see any benefit to this feature, and in fact, when you interrupt the spinning process, less water is hurled off."
- "The OXO Steel came close to our top pick at drying produce"
- Supports: spinner_drive (pump one-handed, cord two-handed), spinner_brake disagreement, steel bowl trade-off. Confidence high.

**Reviewed, The Best Colanders** https://www.reviewed.com/ovens/best-right-now/the-best-colanders
- Editor's note: picks "based on examining user reviews, product specifications, and, in some limited cases, our experience" (so less hands-on than ATK).
- OXO 5 qt: "Covered from rim to base with perfectly sized holes"; Bellemain: "because the colander is perforated all over and the base keeps it up off of the ground, it drained the water with surprising ease."
- Comfify over-sink 6 qt: "Its adjustable arms were helpful for fitting it to my oversized farmhouse sink"; "the largest capacity that we tested, making it overkill for a pound of pasta"; "The silicone coating made it a bit troublesome to clean."
- OXO 3.5 qt silicone collapsible: "The very small holes were perfect for rinsing rice but they became waterlogged when draining the pasta"; "Not only did the silicone coating cling to food, it was difficult to clean."
- Joseph Joseph plastic: "The holes were slightly too large to rinse rice and some of the pasta slipped through them".
- LiveFresh 5 qt "micro-perforated": "some reviews do say that they are a bit large for draining smaller foods like quinoa or rice"; "At 5-quarts this is a pretty standard size colander".
- "Consider stainless steel models for durability and even drainage"
- Supports: hole_coverage, colander_format, sink_fit, capacity (5 qt standard, 6 qt overkill for a pound), body_material. Confidence medium-high.

**Bon Appétit, The Best Salad Spinners According to Bon Appétit Editors** https://www.bonappetit.com/story/best-salad-spinner
- Zyliss Easy Spin pull cord: "The pull cord gives you maximum power for minimum work, as well as the quickest, driest spin. Bonus points for a brake button that actually performs ... leaving you with fluffed-up leaves".
- Mueller: "With a five quart capacity, it's about 20 percent smaller than the others but will still easily handle enough salad for four."
- OXO Little: "If you're a family of one or not really into salad but you love herbs".
- OXO stainless: "the stainless steel bowl makes it harder to quickly assess how dry your greens are."
- Supports: the drive and brake disagreements; 5 qt as the full-size point. Confidence medium (editor picks, no measured test described).

**King Arthur Baking, Do I really need to sift flour? (24 June 2024)** https://www.kingarthurbaking.com/blog/2024/06/24/why-sift-flour
- "Do you really need to sift flour? Occasionally — but for the most part, not anymore."
- "The same effect can be achieved by tapping the ingredient through a fine-mesh strainer."
- "For baked goods where a light texture is the goal, like Angel Food Cake or Genoise, sifting your flour before mixing will yield an extra-light, fluffy, airy crumb."
- Supports: second source for the sifter judgement. Confidence high.

### Brand spec pages (which fields brands publish)

**Rösle (DE), product pages, read 2026-10-25.** Each lists Breite, Material, Spülmaschineneignung and "Maschenweite":
- https://www.roesle.com/rundgriff-kuechensieb-feinmaschig-oe-20-cm/ : "Rundgriff Küchensieb feinmaschig Ø 20 cm"; "Material: Edelstahl 18/10"; "Maschenweite: 0,05 cm"; "Spülmaschineneignung: Ja"; "zum Bestäuben mit Puderzucker und Sieben von Mehl".
- https://www.roesle.com/rundgriff-kuechensieb-feinmaschig-oe-12-cm/ : "Maschenweite: 0,05 cm".
- https://www.roesle.com/rundgriff-kuechensieb-grobmaschig-oe-20-cm/ : "grobmaschig"; "Maschenweite: 0,16 cm".
- https://www.roesle.com/rundgriff-teesieb-feinmaschig-oe-8-cm/ : "Teesieb feinmaschig Ø 8 cm"; "Maschenweite: 0,033 cm".
- https://www.roesle.com/gastro-gaze-sieb-oe-25-cm/ : "Die extrafeine Maschenweite hält Fruchtfleisch, Haut, Kerne und grobe Stücke zurück"; "Maschenweite: 0,11 cm".
- https://www.roesle.com/spitzsieb-oe-18-cm/ : conical "Spitzsieb"; "Lochdurchmesser: 0,1 cm" (a hole diameter, so a perforated cone, a China cap).
- Supports: mesh_fineness (labels inconsistent within one brand), the opening-size scale. Brand-specific facts, not generalised. Confidence high.

**RSVP International, Shopify product data** (collection JSON at https://rsvp-intl.com/collections/colanders-strainers/products.json, /flour-sifters/products.json, /tea-infusers/products.json)
- Conical mesh strainers 3, 4, 4.75, 6.25 and 8 in: "Measures 8-inches in diameter with a very fine mesh"; "Extra fine mesh cone shaped strainer"; "Made of durable 18-8 stainless steel". No mesh number.
- Collapsible colander: "Designed with a stainless steel rim, handles and base and food safe silicone ... Collapses to 1-inch and expands up to 4.5-inches in height. Heat safe up to 445°F (230°C)."
- Baby colander: "precision pierced drainage holes".
- Sifters: "classic crank style flour sifter"; "Squeeze style flour sifter" (Triple Mesh); "Vintage inspired sifter with easy one hand operation"; capacities 1, 3 and 5 cups.
- Infusers: mesh balls 1.75 to 3 in, spoon, floating, pyramid, novelty shapes.
- Supports: listing fields (diameter, capacity, steel grade, dishwasher safe), no mesh number, sifter_style values, infuser_style values. Confidence high.

**Küchenprofi (DE)**
- https://www.kuechenprofi.de/Kuechensieb-DELUXE/2506102818-VARIANTE : "Die feine Lochung ist ideal zum Sieben von Mehl"; "mit praktischem Gegengriff"; fields Durchmesser, Material, Spülmaschinengeeignet; no opening.
- https://www.kuechenprofi.de/Kuechensieb/1109902807-VARIANTE (tea strainer): "die feinen Maschen halten Schwebstoffe zurück"; no opening.
- https://www.kuechenprofi.de/BAKE-Mehl-und-Puderzuckersieb/1007002800 : "mit praktischer Einhand-Bedienung".
- Supports: mesh not quantified on a second German brand; one-hand sifter value. Confidence high.

**Zyliss (US), Shopify product JSON**
- https://us.zyliss.com/products/swift-dry-salad-spinner : "easy one-handed pump action. The built-in stop button with quick braking action".
- https://us.zyliss.com/products/easy-spin-salad-spinner : "The smaller model (23cm / 9") holds 2-4 portions, while the larger version (27cm / 10½") can handle 4-6 portions"; "the retractable cord and stop button"; "non-slip base".
- Supports: brands describe drive and brake in words; Zyliss states capacity as portions and diameter, not quarts. Confidence high.

**Finum, permanent filters** https://www.finum.com/brewing-2/tea-systems/permanent-filters/ and https://www.finum.com/portfolio/brewing-basket-l/
- "The finum® permanent filters offer ample room for tea leaves to unfold and to release their full flavor. They are made in Germany out of stainless-steel micro-mesh"; "suitable for mugs & pots".
- Supports: the basket-style argument (a brand claim, paired with ATK). Confidence medium.

### Primers and standards

**Wikipedia, Colander** (raw wikitext): "perforated with holes used to strain foods such as pasta or to rinse vegetables"; "A sieve, with much finer mesh, is also used for straining"; materials "light metal, such as aluminium or thinly rolled stainless steel ... plastic, silicone, ceramic, and enamelware".
**Wikipedia, Chinois**: "a conical sieve with an extremely fine mesh. It is used to strain custards, purees, soups, and sauces"; China cap "is a perforated metal conical strainer with much larger holes than a chinois".
**Wikipedia, Salad spinner**: "It uses centrifugal force to separate the water from the leaves"; "crank handles, push buttons and pull-cords"; "The water is driven through the slits in the basket into the outer bowl."
**Wikipedia, Tea infuser**: "Infusers with large holes may not catch all the leaves, requiring the use of a tea strainer"; shapes "spherical, conical and cylindrical".
**Wikipedia, Tea strainer**: "placed over or in a teacup to catch loose tea leaves".
**Wikipedia, Tamis**: "a disc of fine metal, nylon, or horsehair mesh"; "Tamises sift and grate ingredients finer than any other utensil".
**Wikipedia, Mesh (scale)**: "Many mesh sizes were historically given in the number of holes per inch"; standards "ISO 565:1990 and ISO 3310-1:2000 (international) ... and ASTM E11:01 (US)"; table: US 60 = 250 µm, US 100 = 150 µm.
**AZoM, Particle Size – US Sieve Series and Tyler Mesh Size Equivalents** https://www.azom.com/article.aspx?ArticleID=1417 : table rows "No. 60 | 60 Mesh | 0.250" mm and "No.100 | 100 Mesh | 0.149" mm.
- Supports: mechanism families, vocabulary, the opening-size scale. Confidence high for definitions.

### Regulator (food contact)

eCFR, read via the eCFR versioner API (raw XML, then text):
- **21 CFR 174.5** https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-174/section-174.5 : "(2) Any substance used as a component of articles that contact food shall be of a purity suitable for its intended use."
- **21 CFR 177.2600 Rubber articles intended for repeated use** https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-177/subpart-C/section-177.2600 : "may be safely used in producing, manufacturing, packing, processing, preparing, treating, packaging, transporting, or holding food"; elastomers list includes "Silicone (Si) elastomers containing methyl groups"; (e) aqueous food: "total extractives not to exceed 20 milligrams per square inch during the first 7 hours of extraction, nor to exceed 1 milligram per square inch during the succeeding 2 hours".
- **21 CFR 177.1520 Olefin polymers** https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-177/subpart-B/section-177.1520 : "may be safely used as articles or components of articles intended for use in contact with food"; "(1)(i) Polypropylene consists of basic polymers manufactured by the catalytic polymerization of propylene."
- Supports: the food-contact judgement and the body_material note. The extraction figures are a single primary source and stay here, not in the JSON. I found no product standard for household strainers, but with no search available I could not look for one properly, so the judgement says "found none" at medium confidence.

### Could not reach

Serious Eats (402 from People Inc for every URL, and WebFetch refused the domain), Wirecutter and CNN Underscored (403), The Kitchn (403), Food Network (403), Food52 (429), Internet Archive availability API (429), OXO (403), EUR-Lex and legislation.gov.uk for EU Regulation 1935/2004 (empty response; WebFetch returned nothing), Reddit r/tea wiki (login wall), Epicurious (404 on guessed URLs; no search to find the right ones), Good Housekeeping (404 on a guessed URL). Amazon listings were not attempted; prior registers record that they block fetches, and no ASIN was known without search.

## Data points used for derived metrics

None. No source computes a number from listing fields for this category, and I did not invent one. The obvious candidate, pounds of pasta per colander from its quarts, rests on one test protocol (ATK drains 1 lb in 4.5 to 5 qt) and one remark (Reviewed: 6 qt "overkill for a pound of pasta"), which supports a typical size but not a formula. The sifted-versus-unsifted flour weights in ATK's how-to (all-purpose 5 oz unsifted, 4 oz sifted per cup) describe the flour, not the tool.

## Numbers in category.json and how many sources stand behind each

| Number | Sources |
|---|---|
| Colander about 5 qt handles a pound of pasta | ATK (4.5 or 5 qt; drains 1 lb in tests), Reviewed (5 qt "pretty standard"; 6 qt "overkill for a pound of pasta") |
| Full-size spinner about 5 qt | ATK (4 to 5.5 qt; OXO nearly 5 qt), Bon Appétit (Mueller 5 qt, "about 20 percent smaller than the others") |
| Cup-size strainer about 3 in | ATK ("about 3 inches wide"), RSVP (3 in), Rösle (8 cm tea strainer) |
| Bowl-size strainer about 8 in | ATK ("about 8 inches"; Rösle 7.9 in winner), RSVP (8 in), Rösle (20 cm) |
| Rösle openings 0.5 mm fine, 0.33 mm tea, 1.6 mm coarse, 1.1 mm "extra-fine" gauze | Rösle product pages (brand facts, each its own page; quoted as Rösle's figures, not generalised) |
| US sieve No. 100 opens at about 0.15 mm | Wikipedia Mesh (150 µm), AZoM (0.149 mm) |

Kept out of the JSON because single-source: colander base at least 1 in and bowl at least 4 in tall (ATK); fine-mesh basket 5.5 cups and 3 in deep (ATK); spinner 1.75 cups runoff space and under 1 cup rewets (ATK); brake within 1 second (ATK); spinner 6 in tall (ATK); 21 CFR 177.2600 extraction limits (one primary source); RSVP silicone colander heat rating 445°F (one brand).

## Against the existing add-on schema

Add-on read: `supplies/kitchen/add-ons/strainer.jsonc`, one field: `mesh_fineness` enum [coarse, medium, fine, ultra_fine, not_applicable, unspecified]. Composed with `kitchen-standard.jsonc` (`materials` with roles including `body`, `handle`, `mesh_screen`; `max_heat_temp`; `dishwasher_safe` with `top_rack_only`) and `supplies-standard.jsonc` (`high_signal_markdown`, `sizing` with dimensions, capacity, weight, pack_count, pieces_included_text, measurements_text). Kinds follow AGENTS.md: vertical anchor, category quality currency, hard filter, sizing, or markdown. Proposals only; nothing in zamana-expertise was edited.

| Facet in this register | In schema today | Proposed kind under AGENTS.md | Note |
|---|---|---|---|
| tool_job | no | hard filter, via a `strainer_type` enum | Proposal: `strainer_type` enum [colander, over_sink_colander, collapsible_colander, rice_washing_bowl, mesh_strainer, conical_strainer, drum_sieve, flour_sifter, salad_spinner, tea_infuser, tea_strainer, other]. `tool_job`, `colander_format` and `infuser_style` partly derive from it at query time. The title names it. |
| colander_format | no; folded into `strainer_type` above | hard filter (the enum) | A product can be both over-sink and collapsible; allow an array or let the over-sink value win. |
| strainer_size | partly: `sizing.dimensions` | sizing | Basket diameter is bought by number for mesh strainers (ATK reviews them by diameter; RSVP and Rösle title them by it). Map to `sizing.dimensions.width` with a comment that it means basket diameter, or add `basket_diameter` inside `sizing`. |
| spinner_drive | no | hard filter (enum) | Proposal: `spin_mechanism` enum [pump_or_lever, crank, pull_cord, other]. Text fact on brand pages ("pump action", "retractable cord"); not reliably answered by a photo. |
| mesh_fineness | yes | keep as the category's quality currency, but redefine values | Drop `medium`: no source uses it, and the label is the unreliable part. Keep [coarse, fine, ultra_fine, not_applicable, unspecified], with extraction instructed to fill from a stated opening where one exists and otherwise from the label with `unspecified` preferred over guessing. Add `mesh_opening_mm: number | null` only if we would augment it; we would not (one brand of three prints it), so it belongs in high_signal_markdown. |
| hole_coverage | no | none (image pipeline) | All-over small holes versus clusters is answered by the photo. AGENTS.md rule 1 keeps it out. |
| colander_base | no | none (image pipeline) | Ring base versus feet is visual; base height is a measurement nobody lists. |
| capacity_qt | yes, `sizing.capacity` (qt, cups, l units exist) | sizing | Normalise to quarts; Zyliss's "portions" do not convert and should stay null. |
| body_material | yes, `materials[]` with roles `body`, `mesh_screen`, `handle` | already covered | Spinner bowls should record body (bowl) and the basket separately; ATK's point is that steel and glass versions keep plastic baskets. |
| pot_hook | no | high_signal_markdown | A construction line; partly visible in photos. Not a filter. |
| handle_join | no | high_signal_markdown | Welded versus soldered is a durability signal the line-by-line pass should keep when stated. |
| spinner_brake | no | high_signal_markdown | AGENTS.md rule 5 cuts curated feature vocabularies; sources disagree on its value anyway. |
| water_clearance | no | none | Reviewer-measured only; top-N research outside the schema if at all. |
| infuser_style | no; folded into `strainer_type` | hard filter (the enum), or add `infuser_form` [basket, ball, spoon_or_tongs, over_cup, novelty] | Ball versus basket is the expert split for tea and is partly photo-answerable; the enum is cheap. |
| sifter_style | no | high_signal_markdown | Small sub-population; crank versus squeeze is in the title. |
| sink_fit | no | hard filter (number) for over-sink colanders only | Proposal: `fits_sink_width_in: { min, max } | null`. Literal-value fit fact; buyers measure their sink. Willing to augment only for over-sink products. |

Fields this register considers noise for this leaf: `max_heat_temp` for everything except silicone collapsibles (and even there, boiling-water draining sits far below the ratings brands state); `sizing.weight`; `sizing.pack_count` beyond counting pieces in a nested set (ATK found the large strainer in a three-piece set coarse and floppy, so the count says nothing about quality). `dishwasher_safe` stays as a field because brands state it, but every ATK review recommends handwashing mesh, so it should not be a filter. "BPA-free" claims (Bon Appétit repeats one) are high_signal_markdown at most.

## Branches

**Revised 2026-10-25 after the blind check.** Each leg is traced to a sentence in category.json or to a quote above. Split 1's question now offers three answers mapping to the three `tool_job` values: "pasta" and other draining (washing produce) → draining; "sauces, flour or tea" (straining liquids, sieving, sifting, rinsing rice, the general-purpose "tea strainer") → fine straining or sifting; "greens" → drying greens. Loose-leaf tea infusers (ball, basket, spoon, novelty) were ceded to `manual-coffee-tea-prep`; there is no longer a `steeping tea` value or an `infuser_style` facet in this register (see correction log, item 1).

**Split 1, tool_job ("Draining pasta, straining sauces, flour or tea, or drying greens?")**

- when `draining`: then_ask colander_format, hole_coverage, capacity_qt; makes_irrelevant strainer_size, spinner_drive.
  - colander_format: queries split the colander shelf by format (over the sink, collapsible, footed), and ATK warns against the novel formats (verbatim above).
  - hole_coverage: ATK "hole size and placement matter" (verbatim).
  - capacity_qt: ATK 4.5 or 5 qt "most useful"; Reviewed 6 qt "overkill for a pound of pasta".
  - Skips: strainer_size is defined on mesh strainers' basket diameter, spinner_drive on spinners. A colander has no value for either.
- when `fine straining or sifting`: then_ask strainer_size, mesh_fineness, pot_hook, sifter_style; makes_irrelevant colander_format, spinner_drive.
  - strainer_size: ATK reviews the two sizes separately and for different jobs (verbatim "about 8 inches" and "about 3 inches wide").
  - mesh_fineness: ATK's fine-mesh "What to Look for" leads with "Truly Fine, Stiff Mesh".
  - pot_hook: ATK "We vastly preferred models with wide, curved hooks".
  - sifter_style: added per the blind check (required fix 3) so dedicated flour sifters get a path instead of falling through with no facet of their own. It sits alongside strainer_size and pot_hook rather than replacing them; a crank or squeeze sifter still gets asked questions built for a mesh strainer, which the check flagged as imperfect but preferable to no path at all.
  - Skips: family properties of colanders and spinners.
- when `drying greens`: then_ask spinner_drive, capacity_qt, water_clearance; makes_irrelevant colander_format, strainer_size, mesh_fineness.
  - spinner_drive and water_clearance: ATK's "Plunger-Style Mechanisms" and "Ample Water Collection Space" (verbatim).
  - capacity_qt: ATK full-size 4 to 5.5 qt versus compact 2.5 qt.
  - mesh_fineness skip, chain of two facts: spinner baskets are "A perforated plastic basket" (ATK) whose water leaves "through the slits" (Wikipedia), so there is no woven mesh to grade; and the fineness scale is defined on woven mesh (mesh_fineness definition).

**Split 2, colander_format ("Sits in the sink, spans the sink, or folds flat?")**

- when `sits in the sink`: then_ask colander_base, body_material.
  - colander_base: ATK "Tall, Wide Ring-Shaped Base" and "Short Bases and Stubby Feet" (verbatim); Reviewed's Bellemain "the base keeps it up off of the ground". ATK and Reviewed disagree on ring versus feet (Reviewed's own top overall pick has feet) — recorded as a new judgement rather than hidden (correction log, item 5).
  - body_material: ATK and Reviewed both steer to stainless for stability and durability (verbatim above).
- when `spans the sink`: then_ask sink_fit. No `makes_irrelevant colander_base` any more: that leg rested on an unsourced chain ("it hangs, so never stands in the water"), and the format values are not exclusive — an over-sink colander can also stand in the sink (correction log, item 8).
  - sink_fit: Reviewed "Its adjustable arms were helpful for fitting it to my oversized farmhouse sink."
- when `folds flat`: then_ask hole_coverage. `capacity_qt` dropped from this leg (it only repeated the draining branch's own capacity_qt ask) and `makes_irrelevant body_material` dropped (RSVP's collapsible colander has a steel rim, base and handles, so material still varies) — both were WEAK in the blind check (correction log, item 8).
  - hole_coverage: Reviewed's OXO collapsible "very small holes ... became waterlogged when draining the pasta".

**Split 3, strainer_size** and **Split 4, spinner_drive**: no branches. Mesh, hook and handle questions apply at every strainer size (ATK raises hooks and handle failures in both the 8 in and the 3 in reviews), and every spinner drive still needs the capacity and runoff checks. Split 4's question is now "One-handed, or fine using both hands?" (correction log, item 9) — the facet's own rationale already supported this framing (ATK: plunger one-handed, crank/cord need a bracing hand); only the question text had lagged behind it.

Dropped while tracing: a `cup-size → makes_irrelevant pot_hook` leg (ATK's small-strainer review asks for "A Wide, Rectangular Stabilizing Hook", so the hook still matters); a `spans the sink → makes_irrelevant capacity_qt` leg (no source; Reviewed comments on the Comfify's capacity). Also dropped (2026-10-25): the `steeping tea → then_ask infuser_style, mesh_fineness` leg and its `makes_irrelevant` list, since `steeping tea` and `infuser_style` no longer exist in this register.

## Trimmed detail

- `mesh_fineness`: ATK's flour-care tip (sift, then wash in cold water because hot water gels starch) belongs to the strainer's care, not its choice.
- `hole_coverage`: ATK found "The exact arrangement of the holes didn't matter as much as the size and number": columns, rings or all-over all drained well.
- `capacity_qt`: Reviewed gives spinner capacity in cups of lettuce (Zyliss Swift Dry 10 cups, OXO Steel about 12 cups); one source each, so not in the JSON.
- `spinner_drive`: the Prepworks press-down bowl "took a full-body press with both arms" when loaded (ATK). One model.
- `body_material`: Bon Appétit's note that a steel bowl hides how dry the greens are.
- `infuser_style`: ATK's winner was "nearly 4 inches in length"; shorter baskets gave weak tea in a 16 oz mug. Single source.
- Food contact: 21 CFR 177.2600(e) caps aqueous-food extractives for repeat-use rubber (silicone included) at 20 mg per square inch in the first 7 hours and 1 mg in the next 2. One primary source, kept here.

## Corrections

1. `vertical` is "other", not "supplies". The brief asked for "supplies", but schema.json's enum is [formulations, machines, fashion, furnishing, other] and validate.py rejects "supplies" (confirmed on the kitchen-boards register in this folder: "'supplies' is not one of [...]"). The scripts are out of scope, so the register uses "other", as the graters run did. The schema needs "supplies" added. **Stale as of 2026-10-25**: schema.json's enum now includes "supplies" and catalog.json lists this leaf under supplies; see the correction log below, item 11.
2. No WebSearch was available (the session's 200-call budget was spent before this run started). Sources were reached by sitemaps and known URLs only, which is why Serious Eats, Wirecutter and EU law are absent. A follow-up with search should look for an EU or ISO product standard for household strainers and for a second hands-on colander test.
3. Renderer note carried from the graters run: tree.py's flowchart only consults the current branch's `makes_irrelevant`, so it draws a later split question under a leg that made it irrelevant. Checked on this register: all three colander_format legs run on to question 3 (strainer size), which split 1's draining leg dropped, and question 3 runs on to question 4 (spinner drive), which the fine-straining leg dropped. Timeline and mindmap are unaffected. Recorded, not fixed.

4. Self-check edits before finishing (each removed an overclaim): mechanism "a fraction of a millimetre" became "about a millimetre or less" (Rösle's coarse mesh is 1.6 mm) and "almost no listing states it" became "few brands state it" (three brands checked); strainer_size rationale no longer says diameter is printed on "most strainers"; the size mapping rule is labelled ours; spinner_drive no longer says Reviewed covered cranks; pot_hook "widest hooks" became "wide hooks"; infuser_style lost an unsourced "balls are small"; sifter_style lost an unsourced "pastry-kitchen tool"; water_clearance no longer says "as decisive as the drive"; the collapsible trade-off lost the single-source "inch of drawer space"; the food-contact claim now names silicone and polypropylene rather than all plastics.

5. Viewer: `tests/viewer-browser.py` passed 6 of 6 (1380, 768, 390 px; light and dark; offline) on a scratchpad copy. The 1380 light flowchart screenshot was read: labels at full size, four legs from the root.

## Corrections after the blind check (2026-10-25)

Source: `check.md`'s "Required fixes" 1–17. All 17 were applied; none were rejected. Numbering below matches check.md.

1. Ceded loose-leaf tea infusers (ball, basket, spoon, novelty) to `manual-coffee-tea-prep`, which names them explicitly and whose own notes.md already routes general kitchen tea strainers back here — removed the `infuser_style` facet, the `steeping tea` tool_job value and its branch, its vocabulary entry ("Brewing basket") and now-orphaned references (`atk_tea_infusers`, `finum_baskets`, `wiki_infuser`, `rsvp_infusers`) and the loose-tea judgement that cited them; rewrote `mechanism.plain` and `summary` to drop "infuser"; `splits` now has 3 `tool_job` branches instead of 4.
2. Rewrote `strainer_size.backfill_note`: dropped "a conical shape is the cone" (it filed RSVP's 3-to-8-in conical mesh strainers as chinois); new rule is diameter-only (up to 5 in cup-size, 6–9 in bowl-size, above that or named "chinois" is the cone) with no gap band, and the thresholds are labelled our unsourced proposal.
3. Added `sifter_style` to the `fine straining or sifting` branch's `then_ask` so dedicated flour sifters get a path; changed `sifter_style.listing_field_hint`/`backfill_note` from title words to description words, since RSVP's sifter titles carry only the model name and capacity, not "squeeze" or "one hand".
4. Resolved the rice-rinsing contradiction by mapping rice washing bowls to `fine straining or sifting` instead of `draining` (matching the facet definition and ATK's own rinsing method), and rewrote the "tea strainer … unless the title says tea" rule, which could not fire: now "tea infuser"/"infuser" titles go to the sibling (item 1) and "tea strainer" titles map to fine straining as a general small strainer.
5. Colander evidence: added a new judgement recording that Reviewed's top overall pick has "non-skid feet that stayed put" against ATK's ring-over-feet finding, rather than hiding the disagreement; reworded `hole_coverage.why_experts_care` to "user reviews Reviewed quotes" instead of "Reviewed found" for the micro-perforated claim; added a methodology caveat to the "bigger holes" judgement's note (Reviewed's guide draws partly on user reviews, not only hands-on tests).
6. Reworded `capacity_qt.why_experts_care`: dropped "is the full-size spinner point" and replaced with ATK's own range ("about 4 to 5.5 qt"); `ba_spinners` is now cited only for its own contrasting claim ("about 20 percent smaller than the others"), not as support for "5 qt is full size".
7. Reworded `hole_coverage` (definition, values, why_experts_care, backfill_note) to grade by hole size and count rather than "all over" versus "clusters", matching ATK's "the exact arrangement of the holes didn't matter as much as the size and number"; added a third value, "fine mesh (not perforated)", so mesh colanders and mesh baskets have somewhere to go.
8. Removed the four WEAK legs: `spans the sink → makes_irrelevant colander_base` (unsourced chain; format values are not exclusive), `folds flat → makes_irrelevant body_material` (RSVP's collapsible still has a steel rim, base and handles), `folds flat → then_ask capacity_qt` (repeated the draining branch), and the `steeping tea → irrelevant strainer_size` leg, which no longer exists because `steeping tea` was removed (item 1).
9. Changed `mechanism.plain`'s mesh-opening range from "about a millimetre or less" to "a few tenths of a millimetre up to about 1.5 mm", which covers Rösle's own 1.6 mm coarse mesh; added `rosle_coarse_20` to `mechanism.evidence`.
10. Relabelled `source` from `researched` to `derived` on `strainer_size`, `capacity_qt`, `spinner_drive`, `spinner_brake` and `body_material` (all are title/description keyword lookups, which the schema defines as `derived`, not something that "has to be found"); appended "Retail listings themselves were not checked this run" to each of their `backfill_note`s.
11. Set `vertical` to "supplies" — schema.json's enum now includes it and catalog.json lists this leaf there, so notes.md correction 1 (which recorded "other" as a workaround) is marked stale rather than deleted.
12. Retitled the `rsvp_strainers` reference from "colanders and strainers product data" to "Shopify catalogue JSON (colander and strainer listings read from it)", since the URL returns RSVP's whole 673-product catalogue, not a filtered collection.
13. Removed `kp_strainer` from `mesh_fineness.evidence` and `pot_hook.evidence` (its "feine Lochung" is perforation, not woven mesh, and its "Gegengriff" is a helper handle, not a hook); reworded `pot_hook.listing_field_hint` to say "Gegengriff" maps to the helper-handle value instead of a hook.
14. Changed `spinner_drive.cold_start_question` (and the matching `splits[3].question`) from "Push-down pump, crank, or pull cord?" to "One-handed, or fine using both hands?", the sourced, novice-answerable distinction (ATK: plunger one-handed; crank/cord need a bracing hand).
15. `colander_format.listing_field_hint`: "expandable" is no longer a standalone over-sink signal — it is paired with "over the sink" before being treated as that format, since RSVP's collapsible also "expands". `colander_format.backfill_note` now states which branch wins when a product is both over-sink and collapsible (spans the sink, since the arms are the primary selling format).
16. Flagged, not fixed (outside this folder's scope, and `zamana-expertise` is not to be edited): skimmers/spider strainers are disowned by both `strainers` and `scoops`; sink drain strainers returned by the bare "strainer" query are unassigned by any leaf seen so far, with `dish-racks` (Sink Caddies) as the likely owner. Recorded in the scope paragraph at the top of this file for the `scoops`/`dish-racks` owners to pick up.
17. Updated the food-contact judgement: added 21 CFR 177.1500 (nylon resins) and EU Regulation 1935/2004 (fetched via WebFetch from eCFR's versioner XML and the European Commission's food-contact-materials page, since EUR-Lex itself still returns an empty 202) and noted that stainless steel, the main material, sits outside 21 CFR Part 177 entirely. Two new references added: `cfr_177_1500`, `eu_reg_1935_2004`.

All three build commands (`validate.py`, `render.py`, `viewer.py`) exit 0 on the revised `category.json`.