Who decides how your drink is made? The process authority, explained.
Neither you nor your co-packer picks the temperature, the time or the pH limit. A process authority does, in a letter called a scheduled process. Here is what goes in, what comes out and what it controls on run day.
By Sam Ronkin · November 12, 2026 · 6 min read
Guide 01 explained the pH 4.6 line and Guide 02 covered the kill step. Both kept saying the same thing: the numbers for your drink come from a process authority. This guide is about that step.
What a process authority is
FDA's acidified-food rule says a scheduled process must be established by a qualified person with expert knowledge, gained through training and experience, in acidifying and processing these foods. The industry calls that person or lab a process authority. Some are university food science centers. Others are private labs.
The scheduled process is what they write. The rule defines it as the process a manufacturer selects as adequate, under its own conditions of manufacture, to keep microorganisms of public health concern from growing. It covers pH and every other critical factor. In practice it is a letter, specific to one product in one package on one kind of line.
From recipe to run
What to send
Expect to provide the full formula by weight, a description of how the drink is made, the container type and size, whether it will be sold shelf-stable or refrigerated, and samples for the lab to measure. The lab checks pH, water activity and Brix, then the process authority decides which rulebook the product falls under.
Which rulebook is your drink under?
Classification drives everything after it: whether there is an FDA filing, what training the plant needs and how a bad batch must be handled. The final call belongs to the process authority. This shows how the definitions work.
How to read the letter
Every line in a scheduled process is something the plant must do, measure or record. Select a line to see what it means on run day.
Illustration only. Fictional product, not a real letter.
Scheduled process
What happens when a number is missed
A measurement outside the letter is called a deviation. Under the acidified-food rule the processor has three choices: fully reprocess the lot with a process the authority approves, process it as a low-acid food, or set it aside for the authority to evaluate. If the evaluation cannot show the food is safe, it is reprocessed or destroyed. One container over pH 4.6 counts as a deviation for the whole lot.
Try a run against the sample letter
Letter limit: 3.9 or below
Letter limit: 161°F or above
- Reprocess the lot
- Process as low-acid
- Hold for evaluation
The FDA paperwork behind an acidified drink
If the product is classified as acidified, three things follow. The plant registers as a food canning establishment on Form FDA 2541 within 10 days of first making acidified foods. The scheduled process is filed on Form FDA 2541e no later than 60 days after registration and before any new product is packed, with a separate filing for each container size. And the people running the line work under a supervisor who has completed an FDA-approved course, usually called Better Process Control School.
When you need a new letter
The letter describes one set of conditions. Change the acid, the sugar, the juice content, the container size, the kill step or the plant, and ask the process authority whether it still applies. A new flavor on the same base is often handled as a version of the original instead of a new review.
How Palate Pack handles it
Palate Pack is a registered food canning establishment, and every product we run has its own scheduled process from an independent process authority. If you already have a letter, send it with your formula and we will check it against our lines. If you don't, use our form builder to prepare a request for Deibel Laboratories, the process authority we work with.
On run day the letter's limits are the batch targets. We measure pH with a calibrated meter on every batch, and the letter and batch records stay together in your brand's file.
FAQ
My drink is naturally acidic. Do I still need a process authority?
The acidified-food filing does not apply to acid foods. You still need someone qualified to confirm the classification and to set a kill step that works, and that is the process authority's job.
Can I bring a letter written for another co-packer?
Bring it. A scheduled process is written for specific conditions of manufacture, so the process authority has to confirm it holds on different equipment before it is used.
Does every flavor need its own letter?
Each product needs to be covered. Close variants are commonly added as versions of one scheduled process, so ask before requesting separate reviews.
How long should I allow?
Plan on four to six weeks from the day the lab has your samples and paperwork, longer around holidays.
Next: Guide 04, bench to batch.
Have a formula but no letter yet?
Tell us what the drink is and where it stands. We will tell you what the process authority will need.
Sources
- Code of Federal Regulations, 21 CFR Part 114, Acidified Foods. Definitions, scheduled process, pH measurement, deviations and records.
- NC State Extension, Scheduled processes. Registration within 10 days; one container above pH 4.6 is a deviation for the lot.
- NC State Extension, Acidified foods scheduled processes "how to". Form 2541e within 60 days of registration and before packing.
- NC State Extension, Resources and steps for acidified processors. Filing per container size; records; pH meter.
- NC State Extension, Acidified Foods Manufacturing School. Supervisor training requirement.
- FDA, Guide to inspections of acidified food manufacturers (archived). How the carbonated and refrigerated exclusions are read.
- Cornell Food Venture Center, Services and fees and FAQ. Turnaround, expedited service and versions.
- University of Georgia Extension, Preserving acidified foods using the hot-fill-hold process (C 1328-03). The process authority classifies the product.
- Kansas State Research and Extension, Hot-fill-hold process for acid and acidified foods (MF3671). Time and temperature used in the sample letter.
This guide is general education, not a process determination or legal advice. Every product needs its own evaluation and scheduled process from a qualified process authority. Regulations cited are current as of November 2026.