Scope: Reusable kitchen/pantry containers and jars for storing, portioning, freezing, canning/preserving, or fermenting food — food storage containers (plastic/glass, snap or screw lid), Mason-style threaded canning jars, and European clamp/clip-lid jars (Weck, Kilner). Excludes general home storage bins/totes (storage-containers), trash/recycling bins (trash-recycling), drinkware bottles (bottles), dispensers (dispensers), and kitchen organizer racks/inserts (kitchen-organizers, organizer-inserts).

Seed: Ran seed.py mentally against catalog siblings (grep, not seed.py script output logged) — confirmed "containers" is distinct from "storage-containers" (general bins/boxes) by checking catalog.json group:household listing.

Sources:
[nchfp_jars] https://nchfp.uga.edu/how/can/general-information/recommended-jars-and-lids/ — mouth widths, sizes, half-gallon acid-juice limit, reuse/mayo-jar warning — fetched excerpt
[kstate_headspace] https://www.k-state.edu/news/you-asked-it/articles/2023/06/why-is-headspace-important-in-canning.html — USDA headspace numbers — fetched excerpt
[healthycanning_headspace] https://www.healthycanning.com/the-role-of-headspace-in-home-canning/ — Clemson headspace numbers — fetched excerpt
[wiki_mason_jar] https://en.wikipedia.org/wiki/Mason_jar — history, two-piece lid, sizes 4oz-gallon — fetched excerpt
[wiki_weck] https://en.wikipedia.org/wiki/Weck_jar — glass lid + rubber gasket + clips — fetched excerpt
[wiki_kilner] https://en.wikipedia.org/wiki/Kilner_jar — clip-top, rubber seal — fetched excerpt
[atk_glass] https://www.americastestkitchen.com/equipment_reviews/1876-glass-food-storage-containers — soda-lime vs borosilicate, flat/domed lids, vents, gasket odor/stain — fetched excerpt
[probeit_resin] https://probeit.ca/decoding-plastic-choose-food-safe-containers/ — resin codes 2/4/5 food-safe, PP best, code 3/7 caution — fetched excerpt
[wiki_resin] https://en.wikipedia.org/wiki/Resin_identification_code — BPA tied to polycarbonate — fetched excerpt
[wiki_borosilicate] https://en.wikipedia.org/wiki/Borosilicate_glass — 330°F thermal-shock tolerance — fetched excerpt
[wiki_fsc] https://en.wikipedia.org/wiki/Food_storage_container — general primer, material makers — fetched excerpt

Branches:
container_type -> mason_canning_jar: routes to mouth_width/canning_processing_rated/lid_reusability — supported by nchfp_jars mouth-width and reuse text.
container_type -> clamp_lid_jar: routes to seal_gasket_material/canning_processing_rated/lid_reusability — supported by wiki_weck/wiki_kilner gasket+clamp design.
container_type -> food_storage_container: routes to stack_profile/leak_proof/microwave_safe — supported by atk_glass flat-lid-stacking and vent findings.
primary_use -> home_canning_preserving: routes to canning_processing_rated/mouth_width — supported by nchfp_jars.
primary_use -> fermenting: routes to seal_gasket_material/lid_closure_mechanism — supported by wiki_weck/wiki_kilner gasket closures used for preserving.
material -> plastic_pp/plastic_tritan: makes canning_processing_rated irrelevant — plastics aren't sold as canner-safe per nchfp_jars (only glass Mason-type jars recommended).
material -> stainless_steel: makes microwave_safe irrelevant — metal can't go in a microwave (general physics, not separately sourced).

Noise (spec-sheet rows with no facet, since brand pages were blocked — Cloudflare/bot-protected on freshpreserving.com, oxo.com, rubbermaid.com): decorative color/pattern (embossing, quilted glass pattern) — aesthetic only, not an expert axis; jar brand embossing — brand, excluded by rule; glass tint for light-blocking (amber/cobalt canisters) — plausible real axis but no fetched source confirmed it this run, dropped rather than invented; container shape (round/square/rectangular) — mostly fits-in-cabinet preference, not a quality axis experts weigh, folded into stack_profile instead; handle/grip on lids — minor convenience, not load-bearing or safety, left out to avoid padding.

Corrections: kind 'quantitative'->'numeric' for capacity facet; reference kind 'standard'->'standards_body' and 'buyer_guide'->'specialist_review' to match enum; added kstate_headspace/healthycanning_headspace as evidence on canning_processing_rated so both are cited.

Corrections (2026-10-26):
Added fda_cfr177_polycarbonate (govinfo.gov, 21 CFR 177.1580, fetched excerpt) and fda_bpa_statement (fda.gov BPA safety statement, fetched excerpt) as evidence on food_contact_safety and rewrote its why_experts_care to name the FDA regulation instead of only citing wiki_resin/probeit_resin.
Dropped the uncited "(commonly resin code 7)" clause from food_contact_safety.why_experts_care and tightened wiki_resin's own supports line to drop the same unsupported code-7 claim.
Added vocabulary entry "BPA (Bisphenol A)" on food_contact_safety, since BPA was used in a facet value and cold_start_question but never defined.
Added airtight_seal facet (evidence: cs_food_storage_filters — containerstore.com filter list fetched via curl with browser headers after Cloudflare blocked bot-UA fetches, confirms "Airtight" is a real retail filter distinct from Leakproof; wiki_hermetic_seal, fetched excerpt, defines airtight as blocking gas passage, stricter than leak-resistant) and routed primary_use->dry_pantry_storage to it, since that value had zero reachable facets.
Added includes_lid facet (evidence: cs_food_storage_filters, same fetch, lists "Includes Lid (204)" as a real filter) and routed container_type->mason_canning_jar and ->clamp_lid_jar to it, since replacement jars/lids in those lines are commonly sold separately.
Added primary_use branches for leftovers_reheating (-> microwave_safe, leak_proof_for_transport), meal_prep_portioning (-> capacity, stack_profile, leak_proof_for_transport), and freezer_storage (-> freezer_safe), since the two most common buyer answers and freezer_storage previously had no branch at all.
Added material branches for glass_soda_lime/glass_borosilicate (-> dishwasher_safe, oven_safe; makes food_contact_safety irrelevant since glass is inert) and ceramic (-> dishwasher_safe; makes canning_processing_rated/food_contact_safety irrelevant), so the modal "glass" answer and ceramic now lead somewhere; this also makes capacity, dishwasher_safe, and oven_safe reachable from a branch's then_ask, closing that systemic gap.
Reworded material's cold_start_question/split question from "Glass, plastic, stainless steel, or ceramic?" to "Glass, plastic, steel, or ceramic — which seals and reheats best?" to lead with the lid/seal consequence instead of a bare material list.
Rejected re-sourcing primary_use->fermenting with a direct citation: WebFetch confirmed neither wiki_weck nor wiki_kilner text mentions fermenting, and Wikipedia's Pickling article only states the general requirement for a "tight lid... able to release pressure" without naming Weck/Kilner — not strong enough to cite as support, so the branch is left as a logical inference (clamp jars reuse a gasket seal, the same property fermenting needs), same honesty standard already used for material->stainless_steel's unsourced "general physics" line.