Low-Acid Canned Foods: FDA's Rules for Small Makers

A low-acid canned food is a food with a finished pH above 4.6 and a water activity above 0.85, sealed in a container designed to keep microorganisms out, and heated enough to be commercially sterile so it can sit on a shelf without refrigeration. Green chile, beans, soups, vegetables and broths in cans, jars or retort pouches are the usual examples. They're held to FDA's strictest food processing rules because a mistake can mean botulism: the maker registers with FDA, files a scheduled process for each product and container size, works under a supervisor trained at a school FDA has approved, codes every container, and keeps a record of every batch. A frozen version of the same food isn't processed to keep on a shelf, so it sits outside these rules. In the example below, a salsa maker sorts five products and finds two planned ones that would bring all of it. Below are the definitions, the steps, the example, and a free checklist.

The short version

• Low-acid: finished pH above 4.6 and water activity above 0.85, other than alcoholic drinks.
• Covered when it's thermally processed in a hermetically sealed container, to be kept without refrigeration.
• Sold frozen: not processed to keep on a shelf, so not these rules; a sealed food sold refrigerated is a question for a process authority.
• Acid added to bring it to pH 4.6 or below: the acidified food rules instead.
• Register on Form FDA 2541 within 10 days, file each process within 60 days and before packing a new product.
• Retort operators and closure inspectors work under someone who completed a school FDA has approved.
• Every container carries a permanent code for the establishment, product, year, day and period packed.
• TaroStack keeps each batch's lot and fields of your own on its batch record. More below.

The definitions

All three are in 21 CFR 113.3. Canned meat and poultry products made under continuous USDA inspection follow USDA's rules instead (21 CFR 108.35(i)). This is general information, not legal advice.

What a low-acid canned food maker does

The approved schools are the better process control schools, run by universities and food processing groups, and the course covers the kind of processing the supervisor will oversee. A process authority sets the scheduled process; how that works and what it costs is in process authority letter.

An example: five products, two planned

Saguaro Salsa Co., a made-up salsa maker in Tucson, Arizona, I use in these examples, sorts what it makes and what it's thinking of making:

The two planned products are the same foods Saguaro already sells, moved off the freezer shelf. That move brings a retort, a scheduled process for each product and container size, a trained supervisor, a code on every jar and pouch, and a record of every batch. Its other choices: keep the green chile frozen, add acid under an acidified food process, which changes the taste, or have a co-packer with a retort and a trained supervisor make the shelf-stable versions under its own registration and filings. The jarred salsa is acidified, with its own rules and pH log; how pH is measured is in pH testing for acidified foods. The tortillas are none of this. How Saguaro plans its tortilla line is in tortilla business plan.

Get the checklist

Download the low-acid canned food checklist. Two sheets: which rules, one line for each product with its pH, water activity, container and how it's kept, where the rules that apply fill in; and what a shelf-stable low-acid product needs before its first batch, each with its rule and a tick. It's an ordinary Excel file with no macros, and it works in Google Sheets, LibreOffice and Numbers.

Where this stops working

A checklist gets a product ready. After that, every batch is a retort log, a closure inspection, a code on each jar and a review of the records, and a jar found swollen in a store months later has to be traced back to the batch, the retort run and every store that got the same code.

How TaroStack does it

TaroStack keeps each batch's lot and fields of your own on its batch record.

Each batch its lot. A batch of green chile takes its chiles, salt and jars off stock, records the lots it consumed, and gets a lot of its own with its dates, the code that goes on every jar. Lot labels print with GS1-128 barcodes for the cases.

The batch record. Fields of your own on the batch record, numbers, tick boxes and initials, hold the retort temperature and time, the initial temperature, the closure checks and who reviewed them, and printable batch-record forms carry the same fields for the kitchen.

From jar to store. Each order records the lots each customer got as it ships, so one recall report shows which stores have a batch and what's still on your shelves.

Batches, lots, lot labels, batch records with fields of your own, and recalls are on every plan, from $49 a month. The first 30 days are free, with no credit card. If you'd like a hand setting up, ask, and we'll do it with you.

Questions people also ask

What is a low-acid canned food?

A food with a finished pH above 4.6 and a water activity above 0.85, heat-processed in a sealed container so it keeps without refrigeration: canned beans, vegetables, soups, green chile.

Do I need to register to make low-acid canned foods?

Yes. Register on Form FDA 2541 within 10 days of starting, and file each scheduled process within 60 days and before packing a new product.

Who needs to go to a better process control school?

The person who supervises retort operators and container closure inspectors has to have completed a school FDA has approved for the kind of processing involved.

Are frozen foods low-acid canned foods?

No. A food sold frozen isn't processed to keep on a shelf, so these rules don't cover it, though other food safety rules still apply.