Does Juice Have a Small Amount of Alcohol?

November 17, 2025 •

3 min read

According to a study published by the National Institutes of Health, all tested brands of orange, apple, and grape juice contained detectable levels of ethanol. Does juice have a small amount of alcohol due to natural processes? This phenomenon is a result of yeast converting the natural sugars in fruit into ethanol and carbon dioxide.

Quick Summary

Natural fermentation can lead to trace amounts of alcohol in fruit juice. Factors like yeast, sugar content, and storage conditions influence this process. The levels are typically very low, especially in pasteurized commercial juices, but can increase in fresh, untreated, or poorly stored varieties.

Key Points

Natural Fermentation: Trace alcohol in juice results from yeast naturally converting the fruit's sugars into ethanol and carbon dioxide.
Pasteurization is Key: Most commercial juices are pasteurized, a process that kills the yeast and bacteria responsible for fermentation, resulting in negligible alcohol levels.
Storage Matters: Leaving fresh or open juice unrefrigerated allows airborne yeast to start fermentation, increasing the alcohol content over time.
Some Juices Ferment More Readily: Juices from fruits with higher sugar content, like grapes, may be more susceptible to fermentation.
Minor and Generally Harmless: The alcohol levels in juice from spontaneous fermentation are extremely low and pose no health risk to the average healthy adult.
Indicator of Spoilage: A slightly fizzy or tangy taste in juice indicates fermentation has occurred, signaling that the product is spoiling.

The Science of Spontaneous Fermentation

Fermentation is a natural biochemical process in which microorganisms, like yeast, consume sugars and convert them into other compounds, including ethanol (alcohol) and carbon dioxide. This process is responsible for producing alcoholic beverages like wine and beer, but it also occurs spontaneously in many sugary foods, including fruit juice.

When fruits are processed into juice, yeast—both naturally present on the fruit's skin and floating in the air—can come into contact with the sugary liquid. Given the right conditions, this yeast begins to ferment the sugars. Factors such as temperature, storage time, and exposure to air can significantly impact the extent of this fermentation.

Why Commercial Juice Has Little to No Alcohol

Most commercial fruit juices are pasteurized, a heat-treatment process that kills microorganisms like yeast and bacteria. This heat-treatment prevents the juice from fermenting and extends its shelf life, making the alcohol content negligible. This is why a sealed carton of apple juice from the grocery store is safe from fermentation. However, once the juice is opened and exposed to the air, or if it is a fresh, unpasteurized variety, the risk of fermentation and a resulting increase in alcohol content rises.

Factors Affecting Alcohol Content in Juice

Several factors influence how much alcohol might be present in juice:

Type of Juice: Some fruits naturally have a higher sugar content, which means more fuel for fermentation. For instance, studies have shown that grape juice can contain higher trace alcohol levels than apple juice.
Storage Time: The longer a fresh juice is stored, the more time yeast has to ferment the sugars. A juice that has been left unrefrigerated and is nearing its expiration date is more likely to contain higher levels of trace alcohol.
Temperature: Yeast thrives in warmer temperatures. Leaving juice out at room temperature will accelerate fermentation, leading to a faster increase in alcohol content compared to refrigerating it.
Exposure to Air: An open container of juice allows airborne yeast to enter and begin the fermentation process. Keeping juice in a sealed, airtight container helps minimize this risk.

The Impact of Storage on Juice Fermentation

Leaving fresh-squeezed juice at room temperature can lead to fermentation within days. The fermentation process will be indicated by a change in flavor—the juice may develop a slight fizz or a tangy, alcoholic taste. While the trace alcohol levels are generally harmless for most adults, this is an indication that the juice is no longer as fresh and may have other spoilage issues.

Juice Alcohol Content: A Comparative Look


Juice Type	Typical Trace Alcohol Content (ABV)	Key Factors	Comment
Pasteurized Apple Juice	< 0.05%	Pasteurization, sealed packaging	Almost no alcohol due to heat-treatment.
Fresh Grape Juice	up to 0.09%	Sugar content, wild yeast	Natural sugars and wild yeast on grapes can lead to slight fermentation.
Leftover Orange Juice	up to 0.7%	Spontaneous fermentation after opening	Can ferment quickly if left unrefrigerated, especially in an open container.
Very Ripe Bananas	~0.05%	Natural ripening process	As bananas ripen, their sugar converts to trace alcohol.
Kombucha	0.5-2% ABV	Intentional fermentation	Deliberately fermented, though sold as "non-alcoholic" by some brands.

Conclusion: Understanding Trace Alcohol in Juice

While it may come as a surprise, the presence of trace amounts of alcohol in fruit juice is a well-documented phenomenon rooted in natural fermentation. For most people, the levels are so minimal they are completely unnoticeable and harmless. Commercial juices are pasteurized to prevent this, but fresh or home-pressed varieties can and will ferment over time, especially if not stored properly. Understanding the conditions that promote fermentation—namely, time, temperature, and exposure to yeast—can help you manage the freshness and quality of your juice. Always practice good food storage hygiene to ensure you are consuming your beverages as intended.

Frequently Asked Questions

No, the amount of alcohol produced by natural fermentation in juice is so minimal that it would not be enough to cause intoxication, even for someone with a low tolerance.

Yes, for the vast majority of cases. The trace amounts are minuscule, and a child's liver can process this alcohol quickly and efficiently. Concerns generally arise only in specific medical situations.

Fermenting juice might have a slightly fizzy texture, a tangy or sour taste, or a faintly alcoholic odor. The container might also look slightly bloated from the buildup of carbon dioxide.

No. While both involve fermentation, wine is intentionally fermented for a specific period to produce a high alcohol content. Fermented juice, on the other hand, is the result of natural, uncontrolled, and minimal fermentation, often signaling spoilage.

A very ripe banana can contain a trace amount of alcohol, approximately 0.05% ABV, as its sugars ferment during the ripening process.

It can be for some individuals. While the amount is insignificant, the taste or association could be a trigger. It is advisable for those in recovery to be mindful of this possibility.

Overnight storage at room temperature can cause a small increase in alcohol content due to fermentation, especially if the container is open. However, the level would still be very low, though noticeable in taste.