How do I work out my shelf life and best-by date?
You establish it by testing the product you actually sell, stored the way it will actually be stored, and recording what happens. There is no lookup table for your product. Most makers get there with a combination of a process authority's view, accelerated or real-time storage trials, and honest sensory checks — and then print a date they can defend.
A date on a jar is a claim
Best-by is about quality rather than safety, but it is still a statement you are making to a buyer, and a retailer will plan around it. Picking a number because it looks right is the kind of thing that comes back when a case turns on the shelf at month nine.
Being able to say how you arrived at the date matters more than the date being long.
How makers actually establish one
In practice it is some combination of these, and the more of them you have the more defensible the answer:
- A process authority's view, if you already have one for the scheduled process
- Real-time storage of the finished product in its actual packaging, checked at intervals
- Accelerated storage at elevated temperature as an early indicator, then confirmed in real time
- Periodic pH and water activity readings on stored samples, against the values you established
- Sensory checks — colour, separation, aroma, texture — recorded rather than remembered
Test what you sell, stored how it is stored
The trial has to use the actual container, the actual closure and the actual fill process. A product in a sample jar with a different headspace behaves differently from the one in your retail pack.
And store it the way it will really live: a pantry shelf, not a fridge, unless the label says refrigerate. If the product will sit in a warm shop window, that is worth knowing before a buyer discovers it.
Write it down as you go
The record is the point. Dated observations against a specific lot, with the readings you took, is what turns a number into something defensible — to a buyer, to an inspector, and to yourself in a year when you have forgotten what you did.
Retailers increasingly ask for the basis of the date on a new supplier questionnaire. Having it written already is the difference between a quick answer and a scramble.
Leave yourself room
A retailer will not accept product arriving with a short remaining life, and many have a rule about the proportion of shelf life left on delivery. A twelve-month date that reaches the shop at month four is a different proposition from one that arrives at month one.
Set the date with your production and delivery rhythm in mind, not only with what the product can technically survive.
Common questions
Check this yourself
This is general information for U.S. food businesses, not legal advice, and rules change. Check it against the sources below and against your own state's rules before you rely on it.