Can You Ferment Garlic in Olive Oil?

Have you ever been tempted to purchase one of those garlic-infused oils in the grocery store or maybe a trendy specialty food store?

They tend to be pricey, so perhaps you’ve wondered if you can just ferment garlic on your own to save some money and add some new flavors to your pantry.

So, can you ferment garlic in olive oil? The short answer is yes. But there is a catch – doing so isn’t always safe.

bulb of garlic, tomatoes, rosemary next to small jug of olive oil

Does Garlic Ferment in Olive Oil?

Yes, garlic does ferment in olive oil because the three key factors for conduction fermentation are present: natural sugars in garlic, natural bacteria that live on the garlic surface, and the anaerobic environment (or environment lacking oxygen) provided by the olive oil.

Like other fruits and vegetables, garlic contains natural sugars and bacteria. When the olive oil and garlic are placed in a jar which is then sealed, certain bacteria will convert the sugars into acid in the process of fermentation.

Is it Safe to Keep Garlic in Olive Oil?

Garlic heads usually contain spores of bacteria that live in the ground. It’s impossible to clean the garlic entirely of these spores and get rid of the bacteria. When the bacteria are in an oxygen-rich environment, they don’t cause any harm. So there’s no need to throw away all your garlic cloves. However, if there’s no oxygen, the bacteria’s spores tend to grow and become hazardous.

When you ferment garlic in olive oil, you usually place the lid on the bottle and close it, creating an anaerobic environment. Such an environment is perfect for the germination of these spores because there’s no oxygen.

Also, the fermented garlic becomes even more toxic if kept at room temperature. Essentially, you’re promoting the growth of bacteria by placing the bottle in a warm environment. Additionally, olive oil isn’t very acidic, which makes the environment more favorable for the hazardous bacteria to grow.

If you eat this garlic or use the oil, you risk botulism poisoning. Some indicators of such poisoning are blurred sight, dilated pupils, muscle spasms, and even facial paralysis. While there’s a medication to prevent the bacteria from causing further harm, it doesn’t reverse the damage.

microscopic image of bateria

All of this sounds frightening. And it definitely is. But don’t rush to the pantry to throw away the fermented garlic if you’ve just bought it. Commercial products contain ingredients and additives preventing bacterial growth. And if you keep fermented garlic in the fridge, such an environment isn’t suitable for the bacteria. However, it’s best to eat it immediately or at least within seven days.

It’s very risky to ferment garlic (or any other vegetable) in olive oil at home. If it’s something you really want to try, you can cook the garlic first before storing it in oil. You can also add vinegar to the mix. The heat will kill off the spores and the vinegar will add acid, both of which will decrease the chance of the hazardous bacteria growing spreading.

You should also be sure to store it in the fridge once prepared. As I mentioned, the cold temperature also makes an unfavorable environment for these bacteria.

As an alternative, you can always crush some fresh garlic and mix it with some olive oil instead (and be sure to eat it straight away and not wait a few days before using it). And instead of fresh garlic, you can also use garlic powder.

half bulb of garlic next to garlic crusher with crushed garlic

What Does Fermented Garlic Taste Like?

When fermented garlic has been stored correctly, it has a sweet, butter-like flavor. The texture resembles JELL-O, so it’s much softer than unfermented garlic. It also doesn’t have the distinctive garlic aftertaste that many don’t enjoy. So even those who don’t like eating garlic might like fermented garlic.

The issue with fermented garlic is that even if it isn’t stored correctly, the taste and the smell will be the same. There’s no way to know if bacteria has affected the oil. For that reason, it’s crucial to be careful with fermented garlic, store it in a fridge for a few days, or use a store-bought product.

In Summary

While you can ferment garlic in olive oil yourself at home, it’s crucial to be aware of the risk of bacterial infection (namely, botulism).

Commercially made versions have been especially treated to prevent any sort of contamination, so it’s important to take certain steps if you’re preparing it yourself at home.

Cooking down the garlic before fermenting, adding acid (such as vinegar), and storing it in the fridge are a few key things you can do to make a product that’s safe to eat. Alternatively, you can try pickling (instead of fermenting) the garlic in vinegar instead.