Pasteurized juice has been heated to a high enough temperature, for a long enough time, to kill harmful bacteria and parasites that can cause serious illness. The most common method heats juice to about 161°F (72°C) for 15 seconds. This process makes juice safer to drink and extends its shelf life, though it does reduce some nutrient content.
How Juice Pasteurization Works
Pasteurization is a controlled heat treatment designed to destroy disease-causing organisms while keeping the juice drinkable. The FDA defines it as “a heat treatment sufficient to destroy vegetative cells of pathogens.” For juice, the goal is a 5-log reduction in dangerous microorganisms, which means eliminating 99.999% of the target pathogen.
The standard process, called High Temperature Short Time (HTST), heats juice to about 161°F for 15 seconds. A more intense version, Ultra-High Temperature (UHT), pushes the juice to around 275°F (135°C) for just 2 to 5 seconds. UHT-treated juice can sit on a shelf unrefrigerated for months, which is why you’ll find some juice boxes in the non-refrigerated aisle at the grocery store. HTST-pasteurized juice still needs refrigeration and has a shorter shelf life.
Research conducted for the National Food Processors Association found that heating juice to 160°F for just 3 seconds is enough to achieve a 5-log reduction in E. coli O157:H7, Salmonella, and Listeria. The slightly higher standard of 161°F for 15 seconds adds a safety margin and also handles Cryptosporidium, a parasite that’s harder to kill than bacteria.
What Pasteurization Protects Against
Raw fruit juice can harbor dangerous pathogens that end up in the product when bacteria from soil, animal waste, or fruit skins get into the liquid during pressing. The organisms of greatest concern include E. coli O157:H7, multiple Salmonella species, Listeria, and the parasite Cryptosporidium parvum. All of these have caused documented foodborne illness outbreaks linked to unpasteurized juice, particularly apple cider, apple juice, and orange juice.
These aren’t theoretical risks. The European Food Safety Authority reported 11 outbreaks linked to Salmonella in vegetables and juices in 2021 alone. Contamination often happens during the cutting and handling of fruit peels and skins, when bacteria on the outside of the fruit transfer into the juice. Pasteurization acts as the safety net that catches whatever contamination made it through earlier steps.
How It Affects Nutrition and Taste
Heat does take a toll on some nutrients, especially vitamin C. Research on orange and carrot juice found that pasteurization at higher temperatures reduced vitamin C content by roughly 15% to 35%, depending on the temperature and duration. At 88°C (190°F) for about 33 minutes, juice retained around 86% of its original vitamin C. At 85°C (185°F) using a different method, vitamin C dropped by about 35%. For context, even the mechanical process of pressing fruit into juice causes around a 22% loss of vitamin C before any heat is applied.
Heat also inactivates natural enzymes in juice, which is actually a benefit for quality. Orange juice contains an enzyme called pectin methylesterase that breaks down pectin, causing the juice to separate into a watery layer and a cloudy sediment. This “cloud loss” is one of the biggest quality problems in the juice industry. Pasteurization deactivates this enzyme, keeping orange juice uniformly cloudy and smooth the way consumers expect it.
The tradeoff is real but often smaller than people assume. Pasteurized juice retains most of its vitamins, minerals, and flavor. The losses are comparable to what happens during cooking vegetables at home.
Cold-Pressed and HPP Juice
Not all juice is heat-pasteurized. High Pressure Processing (HPP) uses extreme pressure instead of heat to kill pathogens. You might see it described on labels as “cold-pressured” or “pascalization.” HPP allows juice to retain more of its fresh flavor and nutrients while still meeting FDA safety requirements.
FDA law requires that juice distributed wholesale to retailers undergo either heat pasteurization or an equivalent process like HPP. Interestingly, neither HPP nor heat pasteurization is required to appear on the label in the U.S. (with an exception for pasteurized orange juice). This has caused some confusion. A few years ago, lawsuits emerged against cold-pressed juice companies that labeled HPP-treated products as “100% Raw” or “Unpasteurized,” which was misleading.
If you want to know whether a juice is truly raw, look for the FDA-mandated warning label. Any juice sold without pasteurization or an equivalent treatment must carry this statement: “WARNING: This product has not been pasteurized and therefore may contain harmful bacteria that can cause serious illness in children, the elderly, and persons with weakened immune systems.” If the label doesn’t have that warning, the juice has been treated in some way to reduce pathogens.
Who Should Avoid Unpasteurized Juice
For most healthy adults, drinking unpasteurized juice occasionally carries a low but real risk. The people most vulnerable to serious illness from contaminated raw juice are young children, older adults, pregnant people, and anyone with a weakened immune system. For these groups, the FDA specifically recommends choosing pasteurized products.
At farmers’ markets and juice bars, fresh-squeezed juice is often unpasteurized and sold directly to consumers. These products may not carry a warning label if they’re sold at the point of production rather than packaged for retail. If the juice is refrigerated and freshly made, the risk is lower than with packaged raw juice sitting on a shelf, but it’s not zero. Asking whether the juice has been pasteurized or treated with HPP is a reasonable question when buying from these vendors.