Methodology

This page is the protocol we hold ourselves to. It is written so you can check our work: if a ranking or a shelf-life number on this site does not follow the rules below, that is a defect you can report and we will correct it.

We do not run a testing lab

We do not buy products and measure them on a bench. Every ranking is a synthesis of evidence that already exists, made legible and comparable in one place. When a claim can only be settled by hands-on testing we do not have, we say the evidence is limited rather than imply a measurement we never made. You will never see the words “we tested” on this site.

The source hierarchy

Not all sources carry equal weight, and for anything touching food safety the order is strict. When we cite a figure, it comes from the highest tier that actually supports it.

• Tier 1, safety authority: USDA / FSIS, the FDA, FoodSafety.gov, the CDC, and the National Center for Home Food Preservation. These set the safety limits on this site. Nothing overrides them.
• Tier 2, university Cooperative Extension: used for method detail and storage guidance where federal sources are silent.
• Tier 3, peer-reviewed work and manufacturer specifications: used for material and product facts (barrier thickness, absorber capacity, capacity ratings), and attributed to the manufacturer where the manufacturer is the only source.
• Community and retailer sources: used only for lived experience and current product facts, never as authority for a safety claim.

How we resolve conflicting claims

• Safety beats convenience. Where a manufacturer or a community thread implies a longer life than a Tier 1 source allows, the Tier 1 limit wins and we say so.
• The conservative number wins. When credible sources disagree within a safe range, we publish the more cautious figure, not the most flattering one.
• Safety and quality are labelled separately. A freezer figure is a quality window, not a safety expiry; a fridge figure for raw meat is a safety limit. We do not let one masquerade as the other.

How the score is built

Each product gets a composite score from five dimensions: Owner Satisfaction (weighted 25%), Value (20%), and the mean of three category-specific dimensions (55%). The weighting and the keyword rubric for each category are fixed in advance and applied uniformly. Owner Satisfaction is driven by real aggregate rating and review volume; Value is deliberately biased toward budget picks, so a premium product has to earn its place through the other dimensions rather than its price tag. The ranking does not bend to whatever we happen to link.

How often we re-check

Every product page carries the date it was last checked, and every guide carries the date it was last updated. Prices and availability drift, so a price shown as current is only as good as that date; when data is stale we point you to check the live price rather than trust a number we cannot vouch for.

What we do not know

We have not run the products through a lab, we do not have field-failure data, and we do not make medical or food-safety guarantees. Questions about whether a specific food is still safe to eat belong with the USDA, the National Center for Home Food Preservation, and university extension services, and we route you to them rather than answer in their place.

How affiliate revenue is separated from the conclusions

This site earns a commission when you buy through our links, and that is disclosed on every page that carries one. The commission does not touch the ranking: the scoring rubric is set before we know what converts, the same formula runs for every product, and a higher payout buys nothing. See our affiliate disclosure for the commercial relationship in full.

Corrections

If a number, a source, or a recommendation here is wrong, tell us and we will fix it and note that we did. Who we are and how to reach us is on the about page.