Editorial · Methodology

How we decide "how long does it last?"

This page explains the source categories, package instructions, editorial applications, and review limits behind the storage guides. Read the source notes on each item for the scope of its evidence.

The short version The source labels distinguish direct sources (A), manufacturer or technical material (B), and editorial synthesis (C). A direct manufacturer source describes that maker's product; it does not mean independent government approval. Guidance is currently based on US food-safety sources unless an item page cites a local authority. More country-specific guidance is coming. When a manufacturer's package instructions are stricter than the category-level guidance, the manufacturer wins. The source-check date is shown on each page; our target re-check interval is 12 months. Editorial contacts handle guide-specific questions and corrections.

The three-tier source hierarchy

Item pages list sources with notes about the guidance they support. Some editorial guides also link claims in the text. A general chart, dataset landing page, or FAQ can support a category baseline without proving an exact keeping period for every food, formulation, and state. A citation list is not a guarantee that every statement has an item-specific source match.

Tier A · Direct source

A Food-safety authorities and direct product sources

A sources include food-safety authorities and, on some product-specific guides, the manufacturer's own instructions. Manufacturer evidence applies to the named formulation, package, and market; it is not independent official endorsement. Directness and independence are different qualities. USDA FoodKeeper, USDA FSIS food product dating guidance, FoodSafety.gov, and FDA storage and labeling guidance are the anchor sources for most storage durations, date-label interpretation, and the safety-vs-quality framing. Some item pages cite local authorities such as FSSAI where country-specific guidance is available. UK and Ireland coverage (FSA UK, safefood, FSAI) will be added as those geographies receive proper category support.

Tier B · Manufacturer and technical guidance

B Package-specific instructions and industry technical bulletins

When a specific product's packaging or a manufacturer's FAQ specifies storage instructions that are stricter than the category default (for example, a refrigerated condiment whose label says "refrigerate after opening, use within 30 days"), the manufacturer instructions override the generic guidance. We never relax safety guidance based on manufacturer claims — only tighten it.

Tier C · Editorial synthesis

C Reasonable editorial defaults

Some guidance is an editorial application of an official category baseline rather than a tested period for that precise food. The item should explain that scope and any uncertainty. If the source does not establish a duration or clock, we do not create a numeric timer simply to complete a table. C material must be assessed alongside the cited primary evidence.

The manufacturer-override rule

This single rule is the simplest version of the trust contract:

If the package says something stricter, the package wins. WillItExpire's category-level durations are baselines, not ceilings. If your bottle of olive oil says "use within 60 days of opening" and our page lists 2 months, we agree. If your jar of mayo says "discard after 30 days" and our page lists 60, follow the jar.

We do not flip the rule the other direction. A manufacturer that says a product is good for longer than the category baseline does not override our shorter duration — manufacturer marketing claims face commercial pressure that food-safety agencies don't.

Confidence levels

Every item page shows a confidence pill directly under the title. The confidence label is an editorial assessment recorded with the item. It is not a certification, and source tier alone does not establish confidence: the food, state, clock, jurisdiction, and conditions must also match.

High confidence Medium confidence Low confidence

High indicates stronger support for the stated guidance. Read the source notes to distinguish an exact item match from an official category baseline; a listed A source alone is not enough to make that distinction.
Medium signals qualifications such as category-level evidence, product-specific scope, or a state that is not fully covered. The label does not supply a missing timer or remove package restrictions.
Low signals limited or indirect support. When a state or elapsed period is unsupported, the guide should say so instead of presenting a precise expiry date.

Risk classification

Next to confidence, every item carries a risk-posture pill that answers a different question: "If I eat this past the listed duration, what's actually at stake?"

Safety concern Quality concern Package-specific

Safety concern means the duration is about pathogen growth or toxin production. Eating significantly past it carries real foodborne-illness risk — raw meat, fresh dairy, leftover proteins, cooked rice (Bacillus cereus), seafood.
Quality concern means the duration is about flavor, texture, nutrition, or peak appearance. Past the duration the food is usually still safe if stored correctly — pantry items, most condiments, baked goods, oils.
Package-specific applies mainly to household items (medications, sunscreens, supplements) where active-ingredient potency is the metric, and the package's printed date is the source of truth.

Spoilage signs and the "when in doubt" rule

Pages include relevant warning signs where supported; the number and kind vary by food and state. Normal appearance or smell cannot prove safe handling. Quality changes, such as freezer burn or a cooking-related green ring around a hard-cooked egg yolk, should be distinguished from safety discard conditions. The rule we apply to uncertainty:

When in doubt, throw it out. The cost of discarding food you weren't sure about is at most a few dollars. The cost of a foodborne illness is days of sickness, possible hospitalization, and (for some pathogens like Listeria in pregnant people or vulnerable adults) much worse.

Do not taste-test food you suspect might be spoiled. Many foodborne pathogens don't change flavor noticeably — a tiny taste is not a safety check.

Review cadence

Every item carries a source-check/review date in its footer. The target source re-check cadence is every 12 months. When a source we cite publishes a meaningful update (e.g., USDA FoodKeeper revises its category guidance), affected items get a forced re-review regardless of how recently they were last touched.

Publication, content modification, and source review are separate dates. Rebuilding a template does not renew a food review. Changes should record their actual scope; a named reviewer is credited for a completed review only when that review has been documented.

How automation and review are used

Shared records produce static pages, with automated tools assisting research, drafting, and consistency checks. Those checks can help preserve citations and product boundaries, but they do not guarantee factual accuracy. The editorial contact label identifies who handles guide-specific questions and corrections. Product-specific and unsupported-state guidance should retain its limits throughout the answer, metadata, checker, and tracking interface.

Corrections and additions

Use the public corrections form for source-backed errors, manufacturer guidance, and new-item suggestions. Reports enter a private review queue; nothing submitted is published automatically.

Dataset export

Download the current reviewed dataset as JSON or CSV. Each record includes cited sources, review month, storage guidance, and package-specific instructions where applicable.

What we don't do

We don't reproduce manufacturer marketing claims. We don't accept paid placements or sponsored content. We don't generate item pages with AI without an editorial review pass. We don't make a duration shorter just to look more cautious; we don't make one longer just to look more permissive. The guidance you see is the guidance we'd give a family member.