Let Crushed Garlic Sit for 5 Minutes, Not 10, for Maximum Allicin

There's an old rule suggesting you should let freshly crushed garlic sit for 10 minutes before eating or cooking it. But newer research shows that a shorter wait time – around 5 minutes – might make more sense.

For decades, health blogs and nutrition sites have promoted the idea that garlic must be allowed to sit for 10 minutes after crushing in order to allow allicin, its most famous bioactive compound, to fully form. This so-called 10-Minute Garlic Rule is often taken to mean that 10 minutes is the optimal resting period for crushed garlic before it's cooked or eaten.

The rule seems to trace back to a 1999 study by Song and Milner which found that crushed garlic retained a good deal of its anticancer activity when it was allowed to rest for 10 minutes before heating. Garlic that was heated immediately after crushing didn't offer the same benefits.

The 10-minute rule has recently gained renewed interest, partly due to a 2025 study by Rababah el al. which measured the allicin levels in crushed garlic at several time points and temperatures. That study found that garlic left at room temperature for 10 minutes produced the highest allicin yield across the tested time points and temperatures.

However, concluding that 10 minutes is the optimal time for allicin formation based on these two studies doesn't make sense. We'll get into that in a minute, but first, let's take a quick look at what allicin is and how it's formed.

Understanding Allicin

Whole garlic cloves are rich in a sulfur-containing compound called alliin, not allicin. When the cloves are physically damaged – for example, by crushing, chopping, or chewing – an enzyme called alliinase comes into contact with alliin, which then begins to convert into allicin.

This reaction is part of the plant's chemical defense system, helping the plant protect itself against pests and pathogens. Interestingly, many defensive compounds produced by plants also benefit humans, allicin being a prime example. A comprehensive review of allicin's potential benefits by Salehi et al. suggests that allicin may have antioxidant, antimicrobial, cardioprotective and even anticancer effects in humans.

Since mechanical disruption is needed to trigger the reaction leading to allicin formation, the idea of waiting after crushing garlic makes sense. But 10 minutes? That seems like a long time for a plant to activate its defense mechanism! Indeed, when you look more closely at the research that inspired the 10-minute rule, it becomes clear that the foundation for the rule is weak.

The Problem with the 10-Minute Garlic Rule

The 1999 study we mentioned earlier first measured the effects of garlic that was heated immediately after crushing, and found that microwaving freshly crushed garlic for one minute essentially wiped out its anticarcinogenic effects in rats. This makes sense since heat is known to destroy alliinase, the enzyme needed to form allicin. However, when the researchers allowed the crushed garlic to sit for 10 minutes before microwaving it, much of the garlic's anticarcinogenic activity was restored.

This is an important finding, but the problem is that the study did not test any waiting times between 0 and 10 minutes. Since allicin needs some time to form, it makes sense that garlic given any time to rest after crushing will outperform garlic that's used immediately. In other words, the 1999 study doesn't prove that 10 minutes is the optimal waiting time – only that it's better than zero.

Likewise, the 2025 study included a zero-minute sample and then jumped directly to 10 minutes. The next time point was 20 minutes. Because the 10-minute resting period resulted in a higher allicin yield than the 0-minute and 20-minute resting periods, the authors recommended a 10-minute resting period for crushed garlic. But again, the study provided no information about what happens at 1, 2, 3, or 5 minutes.

Fortunately, there is a study that fills this gap, and we'll look at it next.

Research Lays Out a Case for a New 5-Minute Garlic Rule

In 2018, a group of researchers led by Dr. Sandra Pedisic from the University of Zagreb set out to measure how much allicin develops in crushed garlic over several short resting periods. Published in the peer-reviewed journal Food Technology and Biotechnology, the study analyzed allicin levels in garlic 2, 5, 8, and 10 minutes after crushing.

The results were revealing: allicin levels didn't steadily climb toward the 10-minute mark; instead, they peaked at 5 minutes and then declined. Specifically, the researchers reported the following concentrations of allicin in fresh crushed garlic with different resting periods:

The Bottom Line

Considering everything we now know, the idea that garlic must sit for a full 10 minutes to maximize its allicin yield doesn't make sense. The studies that inspired the 10-minute garlic rule did so because they never measured anything between zero and ten. When shorter resting periods are actually tested – as in the Croatian study – allicin appears to peak well before the 10-minute mark.

If your goal is to maximize allicin formation before cooking, letting freshly crushed garlic rest for about 5 minutes seems to make the most sense. If you cook it much sooner, alliinase may not have enough time to convert all of the alliin into allicin before heat destroys the enzyme, so you end up with less allicin. On the other hand, if you wait much longer than 5 minutes, you'll also end up with less allicin as the compound begins to break down into other compounds.

References

• K. Song and J. A. Milner (1999). Heating garlic inhibits its ability to suppress 7, 12-dimethylbenz(a)anthracene-induced DNA adduct formation in rat mammary tissue. The Journal of Nutrition, 129(3):657-61.
• Rababah et al (2025). Fresh crushed garlic exhibits superior allicin and pyruvic acid stability, while fresh sliced garlic leads in phenolic and antioxidant content. Applied Food Research, 5(1).
• Salehi et al (2019). Allicin and health: A comprehensive review. Trends in Food Science & Technology.
• Pedisic et al (2018). Retention of Bioactive Compounds During Domestic Processing of Croatian Domestic Garlic (Allium sativum L.). Food Technology and Biotechnology, 56(4):590-596.

Published: November 21, 2025