The Rigorous Testing Costco's Kirkland Milk Has To Go Through Before Landing On The Shelf

You might've heard some alarming things about the Food and Drug Administration. According to news articles and social media posts, the FDA put milk safety testing on pause in April 2025. Experts say the headlines miss key facts, but many Americans are still wary. According to Reddit, concerned shoppers should turn to Costco. "My wife is a professional baker," one Redditor wrote. "Yesterday she came home and pointed out that since the FDA is going to stop testing milk, that Costco was a great source of milk. They have very high testing standards." This isn't the first time Reddit has praised Costco's Kirkland-brand milk (even though the cartons are a pain to open). Commenters consistently report that Kirkland milk stays fresh longer than other brands. But is it really safer?

Yes. Costco holds its milk suppliers to an exceptionally high standard. Meeting federal safety requirements isn't enough: Suppliers have to surpass them. Costco takes a lot of pride in Kirkland, its beloved store brand. According to CEO Ron Vachris, Kirkland products don't hit the shelves unless they have an edge on competitors. That means lower prices, higher quality, and strict safety standards. There's no need to rush out and buy a Costco membership, though. Despite the headlines, standard supermarket milk won't kill you.

Costco keeps a close eye on its milk suppliers. Each year, the brand sends third-party auditors to suppliers for surprise safety and animal welfare audits. Occasionally, Costco staff tag along to audit the auditors. While the government runs annual tests on water used to process dairy, Costco tests all the water at processing facilities — including water used for sanitation. Apart from careful audits, each batch of Kirkland milk goes through a battery of 60 microbial tests. Food scientist Bryan Quoc Le, PhD, told Reader's Digest that Costco's testing is extensive — even for high-end suppliers. "Running extensive microbial tests is common among high-standard dairy producers," Le explained, but added that "60 tests per batch is above average."

The safety standards don't stop when the milk leaves the processing plant. One Redditor, who claimed to work at Costco, said the chain's safeguards include regular temperature checks and extra steps to make sure dairy remains cold on its trip from truck to refrigerator. Costco's Costco-size portions may help keep milk fresh, too, since bulk orders can cut down on transport time. Don't be fooled: Your milk is still subject to the same tests, but FDA cuts still impact customer safety. Cuts have slimmed down support staff and communications teams, making it harder for the agency to warn customers when pathogens do slip through the cracks. Want to do your utmost to stay safe? Costco is a good bet.

First things first: The dairy industry has not turned to all-out anarchy. It's not as though your milk now goes straight from cow to carton, no questions asked. The headlines may seem alarming, but experts say that milk still goes through the same tests as before. So what's up with those headlines? In April 2025, the FDA suspended a program that tested the accuracy of lab equipment. As part of the program, the organization sent labs samples of milk spiked with germs, chemicals, or other contaminants. After the labs ran the samples, the FDA would check results to make sure their equipment was up to par. According to the FDA, the program will be back soon. "The Food Emergency Response Network Proficiency Testing Program is currently paused but will resume once transferred to another FDA laboratory — an effort that is actively underway," the agency told Food Safety Magazine.

Realistically, the chances of getting a bad batch of milk are still slim. The United States has some of the highest food safety standards in the world, and milk is one of the most highly regulated items. It's also standard for high-quality dairy suppliers, including the ones Costco uses, to double-check the FDA's work through third-party labs. Still, there's no word on when the program will return, and it's possible that labs might lapse in the meantime. That's bad news for suppliers with bare-minimum safety requirements, but business as usual for Costco.