Q. My mother-in-law makes the most amazing pesto using basil and garlic that she grows in her garden. She only makes it at the end of the summer when all the ingredients are fresh, and the whole family gorges on pesto for a few weeks until it’s all gone. When I asked her why she doesn’t preserve it or freeze it for the winter, she shakes her head and refuses to even consider it. I have been wondering if we could possible freeze her pesto in small batches to eat throughout the winter. The whole family thinks I’m crazy, but I’ve got to know the answer! Can you freeze fresh pesto?
A. Good news! You can freeze fresh pesto. Traditionally, home preservers have not canned pesto often because the fresh herbs in oil are a breeding ground for bacteria if not sealed properly, and so most people don’t risk it. As for freezing, when olive oil is frozen it becomes cloudy and takes on a different consistency. This can be alarming to some, who think the oil is being spoilt. It’s not. Olive oil goes cloudy at low temperatures, but will return to its normal colour and consistency when brought back to room temperature. That means you’re good to go when it comes to freezing pesto!
One detail to note about freeing pesto is that the basil will change colour and go dark, almost black. The bright green colour of fresh pesto won’t hold up to being frozen. This doesn’t affect the taste or the quality of the product, but aesthetically it changes. So don’t be alarmed when your pesto looks different coming out of the freezer than it did going in.
How do you freeze fresh pesto?
To freeze fresh pesto, the fresher the better. Try to freeze it shortly after it has been prepared. Portion the pesto out into the serving size you prefer. Then, scoop the pesto into small freezer bags or hard freezer containers with lids. Some people freeze their pesto in ice cube containers and then pop the frozen cubes into freezer bags. All of these methods work well. Seal the freezer bag or container, then label and date it. Place in the coldest part of the freezer.
To use frozen pesto, simply remove the desired amount from the freezer and add it directly to the recipe. You can also thaw it in a small saucepan over low heat. You may want to check the flavour and adjust as necessary before serving, but it should taste pretty much the same as it did before being frozen. To return the pesto to a bright green flavour, add some finely chopped fresh basil to the pesto before serving.