The milk

Where the milk comes from

Updated October 2026

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Composition moves through the year The standard of identity has numbers in it One supplier, or several Ask what happens before it reaches you Record the source against the batch Have a second supplier before you need one References

Milk is not a standard input. It changes with the herd, the feed and the season, and a cultured product tracks those changes more closely than makers expect.

Composition moves through the year

Fat and protein content shift with lactation stage, feed and weather. A yogurt made to a fixed method on spring milk and fall milk will not set identically, which is a consistency problem arriving from outside your process entirely.

The standard of identity has numbers in it

Yogurt requires not less than 3.25 percent milkfat and not less than 8.25 percent milk solids not fat. Those are properties of what you start with as much as what you do, so knowing the composition of your milk is part of knowing whether your product meets the standard.

One supplier, or several

A single farm gives character, a story and exposure to one herd’s problems. A processor supply gives consistency and no story. Both are legitimate and the choice shapes the product and the marketing together, so it is worth making deliberately rather than by whoever answered first.

Ask what happens before it reaches you

How soon after milking it is chilled, how it is transported, how long it is held. A product made from milk that spent a day getting cold is a different product, and the effect shows up as off flavors and inconsistent sets rather than as anything obvious.

Record the source against the batch

Supplier, collection date and, if you can get it, the composition. That link is what distinguishes a process drift from a raw material change, and those have completely different fixes.

Have a second supplier before you need one

A single-farm supply is a story and a single point of failure, and a herd problem or a vehicle breakdown stops production entirely. Knowing who you would call, and having made the product on their milk once, is the difference between a bad week and a missed month.

References

21 CFR 131.200, Yogurt: not less than 3.25 percent milkfat and not less than 8.25 percent milk solids not fat, with “a pH of 4.6 or lower measured on the finished product within 24 hours after filling.” law.cornell.edu

21 CFR 1240.61, Mandatory pasteurization for all milk and milk products in final package form intended for direct human consumption, which prohibits delivering such a product into interstate commerce unless it has been pasteurized or is made from pasteurized dairy ingredients. law.cornell.edu

Written from federal regulation and FDA guidance, not from a laboratory. Pasteurization of milk and milk products in final package form for interstate commerce is a federal requirement, and what your state permits inside its own borders is a separate question. Anything here is a starting point for a conversation with your state department of agriculture, not a determination that you comply.