In this brief guide, we are going to answer the question “what is the best way to preserve garlic?” and discuss other questions related to the matter.
What is the best way to preserve garlic?
The best way to preserve garlic is by freezing. A study showed that frozen storage at -20°C maintained the antioxidant activity of garlic better than raw storage (1).
There are several methods for preserving garlic. However, freezing is the easiest, most efficient way of preserving garlic and it retains both flavor and aroma. The texture of garlic becomes a bit mushy when frozen, but it will not affect the quality of the dish.
To prevent garlic from enzymatic browning by the action of peroxidase during freezing storage and freeze-thaw process, garlic can be blanched. When properly done, the blanching will inactivate the enzyme without damaging the aroma and pungency of the garlic. The best blanching condition is boiling in water at 100 °C for 45 s following cooling in an ice bath. Blanching also decreases the texture damage caused by freezing and delay microbial spoilage (2).
How to prepare garlic for freezing
Garlic must be peeled and washed before freezing. Peeling garlic is a bit time-consuming.
There are 3 common ways to peel garlic quickly.
- Use the flat side of a knife to press on the clove until the skin breaks. Then peel off the skin using your hands.
- Place the garlic cloves inside a jar. Close the jar and shake it hard until the garlic skins start to separate.
- Place the garlic cloves inside a silicon tube made by rolling a silicon sheet. Rub apply some pressure and rub on the tube until the skin separates.
Garlic can also be frozen without peeling, but any dust and dirt on the peel will cause spoilage. Peeling before freezing also saves time, as peeled garlic can be added straight to the dish without further preparation.
After peeling, the garlic cloves must be washed in cool water and then dried with a paper towel that is allowed to air dry. Freezing garlic cloves with water will spoil them soon.
How to freeze garlic
There are quite a few ways to freeze garlic. You can either freeze garlic cloves whole, chopped or pureed.
To freeze whole garlic cloves:
- Place the garlic cloves inside a ziplock bag.
- Squeeze out all the air.
- Label and freeze.
An alternative method to freeze whole garlic cloves:
- Place the garlic cloves on a tray lined with parchment paper. Make sure that the cloves are not touching each other.
- Freeze for a few hours.
- Transfer the frozen garlic cloves into a ziplock bag.
- Squeeze out all the air.
- Label and return to the freezer.
To freeze chopped garlic:
- Chop the garlic finely.
- Transfer the garlic into a ziplock bag or an airtight container.
- Label and freeze.
To freeze pureed garlic:
- Place the garlic cloves in a food processor.
- Add some oil. The usual ratio is 2 parts of oil to 1 part of garlic.
- Blend until the garlic and oil form a smooth puree.
- Immediately transfer into an airtight container or ziplock bag. Garlic puree must not be left at room temperature even for a short period.
- Label and freeze.
Tips for freezing garlic
- Always select fresh garlic that is free from damage. If there are brown spots on the garlic and the colour is more yellow than white, do not use those cloves. Do not use mushy bruised garlic.
- Store fresh garlic in a dry and dark place before freezing. If kept at a high temperature, the shelf-life of garlic will shorten and it is more likely to grow mold.
- Do not use garlic cloves that are sprouting. Sprouting garlic will have green roots at the centre of the clove. Sprouting garlic is very bitter and not edible.
- Always use clean zip lock bags or airtight containers.
- Store garlic away from fresh vegetables and fruits. Garlic has a very strong aroma that may contaminate the other fruits and vegetables in the freezer.
- Make sure that the garlic cloves and the storage container are completely dry before freezing, Even a small amount of water can cause spoilage.
You may extend the shelf life of garlic cloves with a blanching procedure prior to freezing. Blanching is a crucial processing step in the industrial production of frozen vegetables; this treatment inactivates the enzymes responsible for color and texture deterioration and reduces microbial load. Some claim that garlic products obtained by completely inactivating enzymes may maintain their appearance for a long time, although the pungent flavor and bioactivity are completely lost. Therefore, appropriate blanching parameters are essential for the quality of garlic products. A study showed that blanching at 100 °C for 45 s following cooling in a water bath did not significantly change the flavor and pungency of garlic (2).
Other methods of preserving garlic
Garlic can also be preserved by other methods such as refrigerating, dehydrating and canning.
Refrigerating will preserve garlic for a shorter time than freezing. Dehydrating will significantly alter the taste of garlic and canning is time-consuming. So overall, freezing is the best way to preserve garlic.
Health benefits of frozen garlic
Garlic is a very important element of the human diet. In raw garlic, the amounts of zinc, manganese, copper, selenium, and iodine in 100 g of garlic are 556.1, 446.9, 143.3, 5.5 and 2.5 mg, respectively. The protein content of raw garlic ranges from 2.6% to 3.0%, depending on the variety of garlic. The average content of free amino acids is 2.13%. Concentrations of dietary fiber and total tocopherols in raw garlic are 2310 and 103.1 mg/100 g weight, respectively. Ascorbic and total polyphenols levels are 73.6 and 1.9 mg in 100 g dry weight. Over 70 fatty acids have been determined, with linoleic (46-53%), palmitic (20-23%), oleic (4-13%), and linolenic (3-7%) acids being most abundant, accounting for 80% of the total lipids (3).
Since freezing keeps the nutrient content close to original, the nutrient loss is minimum. Other than prolonging the shelf life, retaining the nutrients is another important factor that decides the success of a preservation technique. Some of its health benefits are (3):
- Helps to reduce blood pressure
- Improves immunity and helps to fight off sickness
- Helps to detoxify the body of harmful compounds
- High in nutrition but low in calories which makes it perfect for any diet
In addition, the garlic organosulfur compounds display potential for suppressing the growth of cancer cells. Consuming garlic helps in preventing many types of cancer, including oral, stomach, esophageal, colon, and prostate cancers (3).
What are the dangers of eating spoiled garlic
Garlic is a low acid vegetable. A bacterium called Clostridium botulinum has inactive spores in low acid vegetables. Sometimes these spores can become active.
The result of consuming bad garlic is botulism, a rare but dangerous foodborne illness and potentially lethal neuroparalytic disease, is caused by ingesting preformed Clostridium botulinum neurotoxin. Improper food handling practices that permit germination and growth of C. botulinum with subsequent toxin elaboration were identified in events involving non canned homemade foods. Home-bottled garlic-in-oil was associated with events in 1991 in California and in 1999 in Florida. In one of these events, the garlic-in-oil was prepared by using home-canning methods; the mixture was heated to a temperature insufficient to kill C. botulinum spores (4).
It is a must to preserve garlic correctly and check for signs of spoilage such as odd coloring and smell before eating.
Other FAQs about Garlic that you may be interested in.
In this brief guide, we answered the question, “what is the best way to preserve garlic?”. We also discussed the ways to preserve garlic by freezing
If you have any questions or comments, please let us know.
- Çubukçu, Hikmet Can, Nazlı Seda Durak Kılıçaslan, and İlker Durak. Different effects of heating and freezing treatments on the antioxidant properties of broccoli, cauliflower, garlic and onion. An experimental in vitro study. S P Med J, 2019, 137, 407-413.
- Zhang, Bin, et al. Effect of blanching and freezing on the physical properties, bioactive compounds, and microstructure of garlic (Allium sativum L.). J Food Sci, 2021, 86, 31-39.
- Tsai, Chia-Wen, et al. Garlic: Health benefits and actions. BioMed, 2012, 2, 17-29.
- Sobel, Jeremy, et al. Foodborne botulism in the United States, 1990–2000. Emerg infec dis, 2004, 10, 1606.