How to Substitute Onions and Garlic With Low FODMAP Infused Oil (Recipe Included)

Following a low FODMAP diet or having to restrict your fructan intake due to digestive disorders like IBS or fructose intolerance means not eating any onions or garlic. The result: Often dull and boring meals.

However, there is a great trick to get the flavor of onions and garlic back without triggering any fructan related symptoms. I’m talking of infused oil. You can buy it as a ready-to-use product or make it easily on your own. And it is even suitable for the Elimination phase for your diet.

Table of Contents

What is onion/garlic infused oil?

Onion or garlic infused oil is a flavored oil (sunflower, olive oil, etc.) where garlic or onion pieces had been added to and removed after a while. During that time their non-FODMAP flavor got transferred, leaving behind a delightful aromatic oil to flavor your dishes.

You can use it instead of plain oil whenever a recipe would normally call for sauteed onions or garlic, but you aren’t allowed to eat them.

Why is onion/garlic infused oil low FODMAP, but onions & garlic are not?

Onions and garlic contain high amounts of fructans, an oligosacharide that represents the “O” of FODMAP. FODMAPs are carbohydrates that are soluble in water, but not in oil. This means that you can add the flavor and aroma of fructan containing foods such as onions or garlic to oil without adding the fructans. Perfect for those who can’t eat onions and garlic anymore.

Is homemade infused oil safe?

There is a small but serious risk of botulism from homemade infused oil. Botulism is a form of food poisoning caused by the microorganism Clostridium botulinum. That microorganism can be in garlic and herbs and thrives in low-acid, low-oxygen environments. That’s the case in oil.

To use homemade infused oils safely:

Use it immediately or at least within 4 days.
Always store it in the refrigerator.
If you want to use it longer, freeze it into ice cubes for convenience. Use them within a month, as the flavor deteriorates over time.

What is the difference to commercial infused oil and where can I get that?

If you want an infused oil that you can use safely for months, then go visit your local supermarket or an online store and get a low FODMAP onion/garlic infused oil there. Those commercial oils are good for months, as they are either acidified or fortified with microbial inhibitors. Just make sure it’s truly infused and not made with garlic extract.

Here are some examples of FODMAP-free infused oils you can find on Amazon:

US readers can order the Fody Foods oils also directly on their website.

How to make your own onion/garlic infused oil

Making your own infused oil from scratch is really simple and cheaper than buying one.

You can either sauté large pieces of garlic and/or onions in oil and then remove the chunks before frying your food with that oil or you can make a small stock of that oil and use it over the next days.

Here is the recipe for homemade infused onion/garlic oil:

Required time

Prep Time: 5 minutes
Cook Times: 5 minutes
Passive Time: 1 hour

Ingredients

1 cup of oil (olive, sunflower, …)
1 onion and/or 3 garlic cloves, peeled and cut into large pieces (For a more potent flavor chop the onions/garlic)

Instructions

Put the oil in a saucepan and warm up gently for 5 minutes on low heat. It is important not to overheat the oil. Only heat it until it is warm but not hot.
Remove the saucepan from the heat and add the onion and/or garlic pieces.
Let it sit for about one hour, so the oil can infuse with the flavor.
In the meantime, sterilize a small clean jar by filling it with boiling water. Let it sit for some minutes before drying and setting it aside.
When the hour is up, remove the onion/garlic from the oil and strain it into the clean jar. Make sure to remove any pieces of onion/garlic. Use a fine wire-meshed strainer with cheesecloth, if you have chopped the onions/garlic, to catch all the remaining pieces.
That’s it. Seal the jar and keep the oil refrigerated. Use it within 4 days max for safety. If you keep it longer, you may risk botulism poisoning.
Freeze it into ice cubes, if you want to keep it longer.

Tips

For a more subtle flavor, leave garlic cloves whole and just quarter onions.
For a stronger flavor, quarter garlic cloves and chop onions.

Some more questions about cooking with onions and garlic

Can’t I just cook with onions or garlic and remove them before eating the meal?

Onions and garlic contain high amounts of fructans. Fructans are not soluble in oil. That’s why infused oils work so well with low FODMAP and any kind of fructan restricted diet. You basically cook with onion or garlic but don’t add any fructans.

However, fructans are soluble in water. This means that if you put onions or garlic in soup, stews, or slow cooker dishes, fructans will leach out into the water. In that case, adding big pieces of onions or garlic while cooking and removing them before consuming the meal won’t work. The water will have absorbed some of the fructan content.

Only if your dish is oil-based, fructans won’t get absorbed. A stir-fried dish, where you’ve pulled the big pieces of onions or garlic out before eating that meal, will, therefore, be totally fine.

I have fructose malabsorption. Do I need to avoid onions and garlic forever?

Not necessarily, but you should avoid eating garlic and onions during the first elimination phase of your FM specific diet. The same goes if you are following a low FODMAP diet.

In the second reintroduction phase, you gradually introduce some of the forbidden foods, amongst them garlic and onions, into your diet and evaluate your new tolerance. If your diet went well, you may be able to eat small amounts of onions and garlic without experiencing symptoms.