Garlic-infused oils are a great work-around for going low-FODMAP without having to actually give up onion and garlic. FODMAPs are not soluble in oil – but volatile oils are – therefore infusing oil with garlic gives you its flavour without the gas-causing components. You simply discard the garlic (or herbs or onion) after extracting some of the flavour.

NOTE: Good-quality garlic-infused oil from the supermarket is an easy and often quite cheap option that is safe and long-lasting, if you can find it.

Safety Precaution: raw garlic can contain dangerous botulism bacteria, so you must heat the olive oil (without ruining the oil’s natural qualities) to at least 85 °C (185 °F) for five minutes or more to kill any bacteria before making your own infused oils with raw garlic. Read about botulism here. 


  • 1 cup of high-quality extra-virgin olive oil
  • 4 bulbs of coarsely-chopped raw peeled garlic (or herbs such as thyme, chilli, etc.)
  • A dark-coloured jar or bottle – you only want enough to last for a week or so, as olive oil is light and heat sensitive, and bacteria can breed


  1. Heat oil over low temperature in a pot. Add chopped garlic and very, very gently heat for 20 minutes. Oil should be hot, but nowhere near boiling.
  2. Pour garlic and oil into a jar or bottle, and then strain out as needed. Leaving the garlic in there allows it to really steep through and provides you with a strong, delicious garlic flavour, whereby you only need a small amount to get the desired result. Experiment with your own oils.

Oil safety

Heating oils to high temperatures (or even moderate temperatures for some oils) destroys the quality of the oils and makes them into a carcinogen. The smoke point is considered the time when the oil starts to degrade, so if you reach this point, you’ve gone too far. Heating oils slowly and gently works best for infusions, so don’t overdo it. You aren’t after deep-fried thyme.

Store-bought infused oils can be left at room temperature because they often have added preservatives.

How to use it?

Infused oils are used to develop deeper flavours in the absence (or in conjunction with) usual cooking. Garlic and onion infusions are a low-FODMAPper’s wet dream, as they add the flavours you love without the bloat. You will need to experiment to see what depth of flavour you can get out of your humble herbs and spices, so do small batches and test them out every time you cook.