# Notes: Openers, Crackers & Crushers This file was missing when the blind check ran (2026-10-25); the checker flagged this as a required fix. It is written now, after the fix pass, reconstructed from the sources already fetched for the register and for the blind check (raw copies in the scratchpad under `check-openers/`), plus new fetches for this fix pass (`fix-openers/`). Quotes below are short excerpts kept for audit, per the skill's "before writing anything, build notes.md" instruction — written late here because the file did not exist, not because the research was skipped. ## Sources (quotes, confidence) **America's Test Kitchen, The Best Can Openers** (`atk_can_openers`). Confidence high. - "Traditional can openers puncture the [lid]... Safety can openers... cut into the side (versus the top) of a can, [which] may expose glue that helps seal the lid to the can. The glue itself is harmless." - "Some users find it takes slightly more force to turn a safety opener's driving handle than the handle of a traditional can opener." - "Some users appreciated that the lock made it possible to turn the opener without squeezing the arms to keep it latched on the can." (a traditional model with a lock button) - "lefties still have to turn the driving handle the 'wrong' direction... top- loading safety models are otherwise more comfortable to use." - "the top of the can will be sharp and slightly jagged. In addition, the can itself will lose some structural integrity" (cutting below the rim). **America's Test Kitchen, The Best Electric Can Openers** (`atk_electric`). Confidence high. - "countertop models took an average of 12 seconds... battery-powered openers took 34 seconds on average." - "The two that were consistently wobbly... stopped working" (of three battery models tested — one, the winner, survived and stayed stable). - "Only two models, one countertop and one battery powered," handled ring-pull cans well, out of eight tested. **Wikipedia, Double seam** (`wiki_double_seam`). Confidence high, narrow claim only. - "mechanically interlocking five layers" — it does **not** mention a sealing compound; that claim was wrongly attached to this source before the fix and has been moved to ATK's "glue" quote above. **Wikipedia, Nutcracker** (`wiki_nutcracker`). Confidence high. - "In the United States, few of the decorative nutcrackers are now functional, though expensive working designs are still available." **Wikipedia, Jar opener** (`wiki_jar_opener`). Confidence medium (single source for motorised claim). - "Jar openers designed to wedge open a lid sealed by a rubber ring were patented and produced in Germany in the mid 1930s, but all production has halted following the turn of the century." The modern screw-lid vacuum breaker rests on Zyliss alone. **Zyliss Jar Opener product page** (`zyliss_jar_opener`). Confidence medium (brand copy). - Description paragraph: "With an extra long handle and an adjustable rubberized band... Ideal for those with limited hand strength." Used instead of the FAQ accordion, whose Q/A pairing read inconsistently across fetches (see corrections log). **The Independent, seven nutcrackers tested (1994)** (`independent_nutcrackers`). Confidence medium (one outlet, dated). - Ratchet: "best of all at getting the shell open without smashing the nut." - Screw/thumbscrew model: "tended to crush rather than crack... Almost useless, but a nice toy." **Australian Macadamia Society, how to crack a macadamia** (`aus_macadamias`). Confidence medium. - "specialist nut crackers available to use or you can just try using a good old hammer or rock!" **McGee and Mathiowetz, AJOT 2017** (`mcgee_2017`). Confidence medium (n=31, one study). - "The greatest torque and success, yet the least amount of grip force... and pain was noted when the left hand turned the lid, the jar was held vertically, the right hand supported the base, and nonskid material was used." Conclusion: "Use of nonskid material without additional reasoning may increase load on arthritic joints, pain, and dysfunction." The best measured condition *used* nonskid material; the warning is a hedged conclusion about using it without the right technique, not a finding that it harms on its own. **Dianat, Asadi and Castellucci, Applied Ergonomics 2021** (`dianat_2021`). Confidence high (n=758). - "A considerable mismatch... particularly for females and those aged 5-9 years. A torque limit of 1.8 Nm was proposed." **Voorbij and Steenbekkers, Applied Ergonomics 2002** (`voorbij_2002`). Confidence high (n=750). - "if opening torque was reduced to 2 N m then 97.6% of users between 50 and 94 years of age... would have no difficulty opening a jar." This measures what grip people can produce, not what any specific lid needs. **IEC 60335-2-14 ed. 5.2 (2006+A1:2008+A2:2012)** (`iec60335_2_14`). Confidence high — read in full via the preview text. - Scope: "This International Standard deals with the safety of electric kitchen machines for household and similar purposes." - "NOTE 101 Examples of appliances that are within the scope of this standard are... can openers... centrifugal juicers... food processors..." (full list has 19 appliance types). **UL 982, Motor-Operated Household Food Preparing Machines** (`ul982`). Confidence high — read in full. - "1.1 These requirements cover household motor-operated food preparing machines and kitchen accessories such as knife sharpeners **and can openers**, that are intended to be operated for short-periods of time..." **Arthritis Foundation, Ease of Use Certification** (`arthritis_ease_of_use`). Confidence medium. - Sitemap check on 2026-10-25: 51 `ease-of-use-products` pages found; none is an opener. Closest matches are easy-open medicine caps, not kitchen tools. **Catalog check**: `catalog.json` entry for `openers` records `"vertical": "supplies"`, not `"other"` — the register's top-level `vertical` field was wrong and is fixed. ## Branches trace (updated 2026-10-25) **Split 1, `job`** — cold-start question now lists all five values: "Cans, jars, nuts, crab and lobster, or crushing (ice/cans)?" - `cans` → then_ask `can_cut_style`, `lefty_friendly`, `pull_top_cans`; makes_irrelevant `nut_shell_range`, `decorative_or_working`, `cracker_mechanism`, `jar_mechanism`. - `jars` → then_ask `jar_mechanism`; makes_irrelevant `can_cut_style`, `nut_shell_range`, `pull_top_cans`, `removable_cutter`, `lefty_friendly`, `decorative_or_working`, `cracker_mechanism`, `power_type`. - `nuts` → then_ask `nut_shell_range`, `decorative_or_working`; makes_irrelevant `can_cut_style`, `jar_mechanism`, `pull_top_cans`, `removable_cutter`, `lefty_friendly`, `power_type`. - `crab and lobster` → no then_ask (no sourced facet exists for seafood crackers beyond `job`; see the new judgement on this); makes_irrelevant every other facet. - `crushing ice or cans` (new leg) → no then_ask; makes_irrelevant every other facet. Matches the existing judgement that no crusher expertise was found. **Split 2, `hand_effort`** — question re-keyed to the facet's own three values ("Squeeze and turn, turn only, or motorised?") so every branch is reachable from an actual answer. - `motorised` → then_ask `power_type` (now reachable; previously no answer to the old two-way question ever produced "motorised"). - `squeeze and turn`, `turn only` → makes_irrelevant `power_type` (unchanged). - `power_type` itself only covers can openers; a motorised jar opener is classified under `jar_mechanism`'s `electric` value instead (see that facet's backfill_note and the `jars` branch above, which drops `power_type`). **Split 3, `can_cut_style`** - `top cut` → then_ask `removable_cutter` (unchanged). - No leg sends "smooth edges" to below-rim cutters any more; the facet's why_experts_care rule now reads "smooth edges means rim cut... below-rim is a separate, weaker result," so a below-rim cutter is a different, worse answer, not a fallback for the smooth-edge path. **Split 4, `nut_shell_range`** - `macadamias too` → then_ask `cracker_mechanism` (unchanged). ## Corrections after the blind check (2026-10-25) 1. Rewrote judgement 7 and `removable_cutter`'s why_experts_care: IEC 60335-2-14 (scope + NOTE 101, read in full) and UL 982 (scope, read in full) both name "can openers," so a real consumer safety standard exists for electric openers. The FDA Food Code is now described as a model code and kept only as the hazard statement for manual cutters. Added both standards as new references. Did not add EN 60335-2-14 (the European national adoption): I could not verify its scope text (WebSearch budget for this session was already exhausted), so per house rules I left it out rather than name an unverified standard — same caution the checker used. 2. Wrote this file (`notes.md`), which did not exist. 3. Rebuilt the `hand_effort` split: the cold-start question now offers the facet's three values directly ("Squeeze and turn, turn only, or motorised?"), so the `motorised` branch is reachable. Corrected why_experts_care ("motors remove grip altogether" → battery motors remove grip, countertop motors still need the lever held) and the backfill_note's default rule (lock-button traditional openers and safety openers now default to turn only, not squeeze and turn). 4. Gave crown-cap bottle openers an explicit exclusion rather than a new `bottles` value: `bottle-wine-serving-tools/notes.md` already claims them under its own `tool_job` value `bottle-cap opener` as of its own 2026-10-25 blind check, so adding a value here would duplicate that claim. `job`'s why_experts_care and backfill_note now say a crown-cap-only tool is out of scope and name that sibling. (Did not edit the sibling file.) Also fixed `job`'s backfill_note, which said a multi-opener "belongs to both values" even though `job` is a single-valued categorical facet; multi-tools are now classified by the title's leading job. 5. Corrected the screw/ratchet kernel claim in `mechanism.plain` and trade-off 3: only the ratchet keeps kernels whole in the cited Independent test; its screw/thumbscrew model "tended to crush rather than crack." Wikipedia also credits only the ratchet with avoiding kernel damage. 6. Softened every macadamia force claim: summary, `mechanism.plain`, split 4's rationale, `nut_shell_range`'s why_experts_care, and judgement 5 (claim reworded, confidence lowered from high to medium, `sources_disagree` set true, note now mentions the Australian Macadamia Society's hammer-or-rock alternative). No source gives a force for any lever cracker; the "ordinary crackers fail" framing rested on Wikipedia citing a vendor page. 7. Fixed the `can_cut_style` mapping: the why_experts_care rule no longer sends a "smooth edges" answer to below-rim cutters as a fallback — below- rim is now described as a separate, weaker result, consistent with ATK's finding that it leaves a sharp, flexing can. Raised `backfill_cost` from low to medium and noted in `backfill_note` not to infer rim cut from "smooth edge" marketing alone. 8. Restated McGee and Mathiowetz in `jar_mechanism`'s why_experts_care and judgement 4: the best-measured condition for grip and success *used* nonskid material; the warning is the authors' hedged conclusion ("may increase load... without additional reasoning"), not a finding that nonskid material alone is harmful. Softened judgement 4's note to match. 9. Completed `makes_irrelevant` on every `job` branch (see Branches trace above) so each path drops every facet that belongs to a different family, including `power_type` on the jars and nuts paths and `jar_mechanism` on the cans and nuts paths. Added a new branch for `crushing ice or cans` that drops every other facet, and added that value to the cold-start question so the leg is reachable. Did not split "crushing ice or cans" into two values, as the required-fix note also allowed dropping or keeping it: no second source distinguishes an ice-crushing buyer from a can-crushing one, and dropping the value would leave the register's "Crushers" label with no facet at all. 10. Trade-off 2 now says "two of three [ATK battery models] broke" rather than implying all battery models failed, since ATK's battery winner survived and stayed stable. Judgement 3's note now cites Dianat's actual emphasis (women and children aged 5-9) and clarifies Voorbij measured people's grip, not any lid's requirement. 11. Judgement 6's claim now reads "price alone does not tell you which" instead of "whatever they cost," and gained a note citing Wikipedia's "expensive working designs are still available" and National Geographic's $188 handmade soldier that did work. 12. Added a judgement stating that crab/lobster crackers and jar openers (past `jar_mechanism`) do not narrow further, because the only further-split data found (Zyliss's 2-10 cm jar lid range) is single-sourced and was kept out of the schema rather than turned into an unverified question. Did not invent a second source for it. Clarified `power_type`'s backfill_note and the `jars` branch so a motorised jar opener is classified under `jar_mechanism`'s `electric` value, not `power_type`. 13. Data-source consistency: removed `cracker_mechanism`'s contradictory "markdown line, not a schema field" note (it is a schema field, used in a branch, and keeps its filter role); fixed `hand_effort`'s default rule (see item 3); `pull_top_cans`'s `backfill_cost` raised to high with a note on its real coverage (one 2021 test, top N only); lowered `decorative_or_working`'s `backfill_cost` from medium to low, since it is a title rule. 14. Minor fixes: `wiki_double_seam`'s reference now supports only "folds... in five layers" (it never mentions a sealing compound); the glue claim moved to `atk_can_openers`, which does support it. `zyliss_jar_opener`'s reference now cites the page's description paragraph ("extra long handle... ideal for those with limited hand strength") rather than the FAQ accordion. On a fresh fetch during this fix pass, that FAQ's limited-hand-strength question actually read "Yes" (not the "No" the checker quoted) — the Q/A pairing in accordion markup may shift between fetches, so citing the stable description paragraph avoids relying on it either way. `wiki_jar_opener`'s reference now notes the lift-off-lid wedge type's production halted after 2000. Judgement 1's note now says "nearly a decade (2015 to 2024)" instead of "a decade." Judgement 8's note now names the `mashers` sibling instead of "the presses sibling leaf," which does not exist. Fixed `vertical` from "other" to "supplies" to match `catalog.json`. Replaced the 403 ACS DOI URL with a reachable OpenAlex API URL for the same abstract. Added the Arthritis Foundation sitemap check as a second `supports` line on the existing `arthritis_ease_of_use` reference. ### Rejected or partly rejected findings - Did not add UL 982's European analogue, EN 60335-2-14: the checker could not verify it either, and I could not re-run WebSearch this session (budget exhausted), so it stays unnamed rather than guessed. - Did not add a `bottles` job value (the alternative the required fix offered): excluding crown-cap openers and pointing to the sibling, which already claims them, avoids two registers claiming the same product. - Did not add a second source for the Zyliss 2-10 cm jar-lid range to build a jar-narrowing question: no second source was found for it in this pass either; the limit is now stated as a judgement instead.