Best by or use by? What the date on a label means

The date needs its label

A date stamped on a drink or chocolate wrapper can look wonderfully definite. October 27 is October 27. The uncertainty lies in the words beside it: best before, use by, packed on or a code with no explanation. Those phrases can describe different things. Read them before deciding that two products have the same kind of deadline.

A quality date does not measure every reason a food could be unsafe. A package can be within its printed date and still be affected by a recall, damaged seal or unsuitable storage. Conversely, a quality date passing does not by itself describe what has happened inside the package. This is a guide to interpreting information, not clearance to eat or drink something you are unsure about.

FDA consumer guidance describes best-if-used-by wording as a quality indication. It also explains that date terminology has varied across packaged foods. That federal overview is useful background; it is not a reason to ignore a specific safety instruction or assume every state uses the same wording. FDA: food dates and storage

Read the words beside the date.

Best-by and use-by are not interchangeable

California provides a concrete reason to avoid that assumption. CDFA’s current guidance distinguishes quality dates from safety dates and describes changes effective in July 2026. Its page assigns different meanings to best-if-used-by and use-by wording. A national article that calls every use-by date a freshness suggestion would lose that distinction. CDFA: food date labeling

For a hypothetical pantry check, imagine two sealed products carrying the same calendar date. One identifies that date as best-if-used-by; the other identifies a safety use-by date. Copying only the numerals into a shopping list would erase information. The phrase, product and storage instructions belong together.

The same caution applies to international packaging. Familiar English words do not establish identical rules in every market. If wording is unclear, the company’s explanation for that exact product is more useful than a general rule remembered from an unrelated food. You can find the responsible business through the company details on the label.

Even the order of a printed date can need clarification. A short numerical code may put the month or day first, while another code may identify production rather than shelf life. Ask what the complete code means instead of assigning a familiar calendar format to it.

Storage changes the question

Look for instructions that apply after opening. An unopened package date does not necessarily describe an opened bottle, a prepared drink or food transferred into a different container. A mushroom powder in its closed pouch and the drink made from it are different storage situations. Do not carry the pouch’s date over to the prepared cup.

Also distinguish refrigeration instructions from serving suggestions. “Serve chilled” describes how a maker wants a drink served; “keep refrigerated” gives a storage instruction. If you cannot tell which applies, ask before assuming room-temperature storage is suitable. Follow the actual product’s instructions rather than borrowing a shelf life from another can or jar.

FDA points consumers to FoodKeeper and other storage guidance. Those tools address ordinary food categories and handling conditions. They do not establish the stability of a particular THC preparation or every mushroom extract. A novel ingredient, formulation or package can require product-specific information beyond a general pantry category. FDA: food dates and storage

A batch code is a different identifier

The small string near a seam may be a lot or batch identifier rather than a date you can decode yourself. Its job may be traceability: connecting the package to production records or a recall notice. Do not translate an unexplained number into an expiry date simply because part of it resembles a month and year.

Photograph the code while it is legible, especially if it sits on a removable sleeve or lid. If a company or recall notice asks for a lot number, that photograph helps identify the exact item. Our guide to reading a batch test report explains another place where matching identifiers matters.

An expiry date on a supplement also deserves its own question. NIH ODS advises consumers about supplement labels and quality; it does not turn the date on one product into a guarantee about safety or effectiveness. Ask what the maker says the date represents, particularly when comparing a food with a supplement. NIH ODS: dietary supplement labels and quality

Make one useful record

For a product you need to check, take one clear photograph showing the date phrase, the date or code, the product identity and any nearby storage wording. If instructions elsewhere on the package qualify what happens after opening, photograph those too. This preserves the information without requiring you to guess a code’s meaning.

Then make the unresolved point specific: “Does this date apply after opening?” or “Which printed string is the lot number?” A reply about a general product range may not answer either question. You need an explanation tied to the package you have, with any recall or safety instruction taking priority over a broad statement about freshness.