Gen Z is discovering cream-top milk. Dairy supplier Straus Family Creamery is delighted.

Dairy milk delivered to your door in a glass bottle was a thing of the past for most. Then Bay Area-based Straus Family Creamery found TikTok fame. Thanks to TikToker Peggy Xu, the self-proclaimed originator of “MilkTok,” demand for the 30-year-old brand’s cream-top milk — a cow’s milk that is produced in a way that allows the fat to rise to the top in the form of cream — is up.

Skyrocketing interest in Straus Family Creamery’s premium organic cream-top whole milk began when Xu recorded herself popping open one of the bottles in June 2023. She then digs her spoon into the bottle’s neck to scoop out some yogurt-looking substance. That is the cream top, for those unfamiliar with non-homogenized milk. According to Xu, it’s her “favorite part" and something she’s been eating as a treat since she was a kid.

For many of the 2 million viewers of the video, however, the cream top was a source of confusion. "I thought the milk was expired,” reads one comment. “Why is it chunky?” asked another follower of Xu's increasingly popular milk posts.

But the cream top isn’t an indication of the milk going bad, says Meryl Marr, the vice president of marketing for Straus Family Creamery. Instead, it’s a result of its freshness.

What makes Straus Family Creamery’s milk different?

“Our milk and all of our products are all minimally processed because we just believe in pure, simple ingredients,” Marr tells Yahoo Life, explaining that they’re pasteurized but not homogenized.

“Homogenization is when milk is processed to align the fat molecules," she says. "That way the cream will not rise to the top. We do not homogenize our milk. That's why it's cream top. And most people in this country have only had homogenized milk.”

Homogenized milk was introduced to the United States in the 1930s, shortly after it became common practice in Canada. It's a mechanical process that evenly distributes fat throughout the liquid to create a smooth texture and consistency. According to the American Dairy Association, that texture is more appealing to consumers. The process also enhances the appearance of milk and, most importantly, extends its shelf life and provides convenience to the consumer who otherwise would need to shake their milk before pouring.

Pasteurization, however, is a different process that ensures milk is food-safe. “Our milk is pasteurized. It is not raw milk,” Marr clarifies. This means that the milk has been heated to kill bacteria that may be harmful to the consumer or cause the milk to spoil. ”The difference in the way that we pasteurize is that it’s not ultra-pasteurized.”

Ultra-pasteurization is heating the milk at a higher temperature — like 280°F for a minimum of two seconds versus regular pasteurization at 161°F for at least 15 seconds. The ultra-pasteurization process is “more lethal to bacteria,” according to the Milk Quality Improvement Program at Cornell College of Agriculture and Life Sciences.

Because it is not ultra-pasteurized, Straus Family Creamery’s milk is less shelf-stable. “It's really a product that you can only get in a certain area of the country,” says Marr. Those close to Straus Family Creamery’s Bay Area farms can get the milk delivered to their door, while other West Coasters can find the brand at their local grocery store.

Marr believes that the product's limited availability adds to its charm, as does the sentimental packaging. “I think [Gen Z] didn't realize milk could come in a glass bottle, that a milk person would drop it off at your door. And then the fact that it's reusable," she says. Buyers are encouraged to bring their bottles back for a $3 refund. The creamery then washes and reuses each bottle as a part of its sustainability mission.

So … about the cream top

Because most Americans drink homogenized milk, Straus's cream top is a novelty. So it’s no wonder that Xu’s videos showing the result of all that cream floating to the top of the milk jug caused intrigue.

Some creators, desperate to find out what the cream top tastes like, got their hands on the product and ate the cream straight out of the bottle like Xu. Others then started a trend of trying the cream with a drizzle of honey on top. Marr says there’s no one right way to do it.

“One of the recommendations that we make that's quite popular is just scoop it out and put it on your toast or a warm scone; use it kind of as your butter. You can also bake with it too. So it's really up to the person how ever they want to use that cream top,” she says. “But if they want to have the cream incorporated [into the milk], it's really just about shaking the bottle up — it will be just as delicious.”

Is dairy coming back?

Right now, TikTok users are just having fun with this food trend. But Marr also suggests that it means bigger things to come for the dairy industry, which has been stacked against plant-based milk alternatives like almond, oat and soy for some time.

“This is an illustration of the return to dairy milk," Marr says, "because I think people have now realized that these plant-based milks are really processed with stabilizers, with oils, with thickeners, all of these things that our dairy milk does not have."

She adds that "demand is up" for Straus's cream-top milk — much to the delight of Albert Straus, founder of the creamery. “We're getting requests from around the world ... it's been fantastic! I've never had anything like this before,” he told ABC7 News.