Techniques of garlic preservation
Garlic is a bulb, similar to onions or shallots, and is a member of the lily family. Because of its intense unique flavor garlic is one of those foods you usually want to have around when cooking. Home grown garlic is the best and learning to preserve it will let you have this great flavor all year round.
Garlic is a low acid food and so it makes preservation a tad more difficult to ensure safety. The typical garlic has a PH range from 5.3 to 6.3 and can support clostridium botulinum if not preserved properly. For this reason do not put garlic in oil and keep it in the refrigerator for more than a few days.
What are my garlic preservation options?
I think I want to freeze my garlic. I will keep some fresh for as long as I can over the winter but I don’t have a great place to keep things cool enough to deter them from spoiling over the winter.
Based on the National Center for Home Food Preservation (NCFHP) I can choose one of these options to freeze garlic:
1. Chop, wrap tightly in plastic, and freeze breaking off portions when I want to use them. I do this for my garlic scale pesto I make from garlic scapes at the beginning of summer and it works great. I can just bend off a portion and use what I need.
2. Freeze the garlic unpeeled and remove cloves as needed. But does this mean freezing the whole bulb? Yes, I think it does. That would seem like the easiest option, but I have heard its not always easy to get the cloves peeled after its been frozen. Anyone have experience doing this?? Let us know how it works in the comment section below.
3. Peel the cloves, puree with oil using one part garlic to two parts oil. Then freeze and break off a portion to use. Note that it cautions you to immediately freeze this mixture because the combination of oil and the low acid garlic supports botulism.
4. A fourth option is to put the garlic in oil. The NCHFP does seem to say that if you submerge the garlic in oil you can freeze it and it will last for several months. Another option is to peel the cloves and lightly toss in oil and freeze. This is the technique done by Margaret Roach from A Way to Garden, a podcast and site I absolutely love. It allows some oil to cover the cloves but also makes it very easy to just go into the freezer bag full of cloves and take a few out when you want them. Sounds good to me. I may very well do this technique this year as I don’t see freezing the whole bulb as being that useful. I may chop some also (see #5 below).
5. **Update** In the October 2015 issue of Cooks Illustrated (my FAVORITE cooking mag) they experimented with various ways of freezing perishables. Specifically for garlic and onions their recommendation was to cut both garlic and onions before freezing. This is because the enzyme in them that reacts with sulfur to produce that wonderful fragrance happens when they are cut. Freezing reduces this enzyme so they recommend allowing the enzyme to do its job before freezing and then preserve the flavors. They also agree that lightly coating the garlic in olive oil to prevent the flavor compounds from oxidizing… although you do not need to do this for chopped onions.