What Is UV-Treated Apple Cider — and Is It Safe to Drink?

It’s apple cider season in the U.S. — the perfect time to pick up a fresh bottle at your local farmers market. While 98% of juices in the U.S. are pasteurized, that’s not always the case with apple cider, especially if you buy it fresh. Instead many bottles of craft or small-batch apple cider are UV treated, which differs from pasteurization. If you happen to notice a “UV treated” stamp on your apple cider bottle, you may wonder what it means and whether or not it’s safe. We can help!

Why is apple cider treated?

You may wonder why apple cider isn’t just pressed and passed on to you. What is there to treat?

“People have always enjoyed the flavor of fresh cider, and fresh apple cider was generally considered [to be] a relatively safe product,” says William Kerr, PhD, a professor in the Department of Food Science and Technology at the University of Georgia College of Agricultural and Environmental Sciences. But back in the late 1990s, apple juice was the source of a few outbreaks of E. coli O157:H7, a foodborne pathogen that can cause bloody diarrhea and a severe form of kidney disease. 

“This caused a push for federal and state agencies to ensure the safety of juices,” Kerr says, which led to companies starting to treat their juices, usually through pasteurization. 

Treating cider and other juices doesn’t just help protect against certain pathogens. It can also extend the shelf life of the product, says Randy Worobo, PhD, a professor of food science at Cornell University. “If you don’t treat it, it’s going to ferment relatively quickly,” he says. “When you treat your cider, you inactivate spoilage microorganisms [as well as] the pathogens that might be contained within the cider.”

What does ‘UV treated’ mean?

Worobo started working with UV treatment in the late 1990s as a way to reduce E. coli 0157:H7 in apple juice. He eventually helped create a process that many apple cider producers now use. 

“UV treatment is a nonthermal processing method,” Worobo explains. This treatment method uses UV light — the part of the light spectrum that can give you a sunburn — to inactivate microorganisms. “Microorganisms don’t tolerate UV light that well. It interacts with their DNA and they die,” Worobo says. 

With UV treatment, “usually, the product passes through clear tubes, which are surrounded by UV lights,” Kerr says. 

“The UV radiation passes through the cider in a manner of seconds, killing 99% of the foodborne illness pathogens,” adds Christine Venema, a food safety educator at Michigan State University Extension.

UV treatment only impacts the microorganisms. “It causes no [other] changes in the cider that gets exposed,” Worobo says. 

UV treatment vs. pasteurization

Pasteurization is perhaps the most common food preservation treatment in the U.S. Unlike UV treatment, it uses heat rather than light. “When you heat-treat foods, you inactivate the microbes that cause spoilage,” Worobo says. 

When cider is pasteurized, it flows through special heat exchangers that quickly heat the juice to 161.6 degrees Fahrenheit and then cool it. Kerr explains: “It is very effective, but does cause a more cooked flavor and perhaps less sweetness.”  

By comparison, UV treatment “doesn’t change the flavor or color of the cider,” Worobo says. “When you pasteurize, you get a little bit of caramelization,” he adds.

Venema agrees. “Apple cider purists claim they can taste a cooked flavor [in] apple cider that has been pasteuriz[ed],” she says. “But rarely can a cooked flavor be recognized in UV-treated cider.”

While not a universal rule, you might find that higher-end or small batch apple cider purchased at your local farmers market or specialty store are UV treated, while cider from larger commercial brands available at your supermarket is pasteurized.

Is UV treatment as safe as pasteurization?

UV treatment has been approved by the Food and Drug Administration (FDA) as a safe and effective treatment for cider. “It is equal to pasteurization,” Worobo says. That means that UV treatment can reduce the pathogen a company is concerned with (usually E.coli or Cryptosporidium, a parasite that causes watery diarrhea) by 99.99%, Worobo says. 

Whether you’re grabbing a bottle of apple cider at your local market or at your grocery store, Worobo stresses how important it is that you buy cider that’s treated in some way — especially if you’re planning to give it to kids. “They’re much more susceptible to foodborne illness.”