Garlic

Heads of garlic. condesign / pixabay.com / 2016 / CC0 1.0

Garlic is a member of the onion family that is grown for its bulb. Inside the bulb are individually-wrapped sections called “cloves”. Garlic is used both for its taste and its aroma.

Some people also use garlic for its reputed medicinal value, but while some studies may look promising, it’s perhaps best to consider the whole “health angle” inconclusive at this point. (See Nutrition section below.)

When the bulb sprouts, it grows leaves that look like chives.

When buying fresh garlic, avoid any that are sprouting, or that feel loose in their skins. A garlic bulb should feel heavy and solid.

Another word for a bulb of garlic is a “head” of garlic.

Apparently there’s a scientific reason why munching on a sprig of fresh parsley or mint after eating garlic will help your breath: the sulphur compounds in the garlic, from whence comes the smell, bind to the chlorophylls in the herbs, neutralising the odour. ^[1]Bingham, Lottie. How to get the most goodness from your garlic. European Institute of Innovation and Technology (Food): Food unfolded. 13 May 2009. Accessed August 2020 at https://www.foodunfolded.com/things-you-did-not-know/how-to-get-the-most-goodness-from-your-garlic

Cooking Tips

Minced garlic. © Denzil Green / 2002

Garlic gives out more or less of its flavour depending on what you do to it. Crushing it releases most of its ‘garlicky effect’, chopping it slightly less; slicing it less still, and leaving it whole the least of all.

The molecule “allicin” in garlic is where its taste and aroma comes from. A raw bulb of garlic in its “found” state contains very little. The molecule is only produced when the flesh of the garlic is injured, which allows an enzyme called “alliinase” and an amino acid called “alliin” to come together to form the allicin. ^[2]Bingham, Lottie. How to get the most goodness from your garlic.

Some studies suggest that after chopping or crush, you should then let the garlic rest to allow the maximum amount of allicin to develop before incorporating the garlic into what you are preparing: “Numerous studies have found that you can get the most goodness out of your allicin by leaving the prepared garlic for ten minutes.” ^[3]Bingham, Lottie. How to get the most goodness from your garlic.

If you subscribe to the thought that garlic mellows in cooking, you’re right, and apparently it’s because “99% of allicin is lost during the frying process.” ^[4]Bingham, Lottie. How to get the most goodness from your garlic.

Take a whole, unpeeled clove of garlic and lay it on a cutting board. Take a broad-bladed knife or cleaver, lay it sideways on the clove and pound it once with your fist. The skin will easily pull away. Continue chopping or crushing as needed.

Technically, if you love garlic, it is better to use a crusher than to chop garlic, because when you chop it some of its flavour and oil can be lost into or onto the chopping board, whereas if you crush it over what it is going into, any drips get salvaged.

If you have to do many cloves of garlic at once, you can blanch them in boiling water for 5 seconds instead of whacking them with the knife.

To roast a whole bulb of garlic, chop off and discard the top third of it. Don’t peel it. Roast at 200 C (400 F) for about half an hour until the head is soft. Remove from oven, let cool, then squeeze the roasted garlic out.

Substitutes

Substitute the bottled, minced garlic for garlic gloves at this ratio:

1 small clove garlic = ½ to 1 teaspoon minced
1 medium-size clove garlic = 1 to 1 ½ teaspoons minced = 5 g / .18 oz
1 large clove garlic = 2 to 2 ½ teaspoons minced
⅛ teaspoon garlic powder = 1 clove garlic
1 teaspoon bottled minced garlic = 2 medium cloves, minced
12 cloves = ¼ cup of minced garlic (fresh or bottled)

Garlic. Conger Design / Pixabay.com / 2016 / CC0 1.0

Nutrition

Some studies have suggested that some compounds derived from garlic may indeed have some health benefits. What’s worth noting, though, is that it seems to be early days still to say that any definitive conclusions have been arrived at, let alone recommendations.

“Garlic… contains phytochemicals belonging to a … group [known as] organosulfur compounds. These molecules are responsible for the aroma and the smell of garlic, but, more interestingly, they have also been linked to potential health benefits. Although the cancer-fighting properties of these molecules, and therefore of garlic, are sometimes discussed and used as a selling point for garlic supplement, as of 2018 there is no clear proof that garlic can be effective in preventing or treating cancer.

However, some clinical trials suggested that garlic could reduce blood pressure in people suffering from hypertension, as well as improving the levels of circulating fats in people suffering from high levels of cholesterol.

It is worth remembering that, when considering herbs and spices, many studies investigate the effectiveness of standardized extracts or supplement, rather than fresh foods. Just as herbs and spices can lose flavour with time or with some drying processes, they can also lose some of the chemical compounds responsible for any beneficial effect they could have on our body.” ^[5]University of Turin. Superfoods: Myths and Truths. Herbs and spices: a different kind of superfood? Module 4.2. September 2020. Accessed September 2020 at https://www.futurelearn.com/courses/superfoods-myths-and-truths/4/steps/796844  

Also worth noting is that any hoped-for benefits may not actually come through when garlic is actually cooked. “Many of garlic’s pharmacologically active compounds are heat sensitive…. just 60 seconds in the microwave has been shown to completely block the herb’s anti-carcinogenic effects.” ^[6]Bingham, Lottie. How to get the most goodness from your garlic. So anyone wanting to naturally tap in any assumed benefits from garlic would want to be eating it raw.

Equivalents

1 bulb = approximately 10 cloves
1 clove = 1 teaspoon peeled, chopped = ½ teaspoon minced = ½ teaspoon dried garlic flakes = ⅛ teaspoon garlic powder
1 tablespoon minced garlic = 6 cloves
40 cloves garlic, roasted = 6 tablespoons roasted garlic purée
4 bulbs = ½ cup whole fresh garlic

Storage Hints

You can store whole bulbs for up to two months in those specialty terra-cotta storage jars. If any garlic you have at home has started to sprout, discard the green sprouty bits, as they will taste bitter. If the garlic has gone dry and spongy inside, just give up on it entirely and bin it.

For directions to pickle garlic, see Pickled Garlic on our preserving site.

You can freeze garlic cloves (peeled or unpeeled) in a freezer bag in the freezer. They’re a bit quicker to use, obviously, if they’re peeled first. When thawed, they’ll be a bit soft, which is fine for use in cooking as opposed to in fresh items such as salsas or salad dressings.

To freeze puréed garlic, purée garlic with oil (1 part garlic to 2 parts oil) and freeze. The oil, in a fridge freezer at least, will stop the garlic mixture from freezing solid, so you can spoon off what you need as you need it.

For a thorough discussion of ways to safely preserve garlic, see: Linda J. Harris (University of California): Garlic: Safe Methods to Store, Preserve and Enjoy.

Garlic in oil

Any homemade mixture of garlic in oil not frozen should be refrigerated and used within 1 week.

The reason is that covering garlic is oil actually provides the perfect environment for botulism. The bacteria that causes botulism is “Clostridium Botulinum.” It can’t grow in the presence of oxygen. When garlic is covered with oil, however, there is no oxygen and the bacteria can thrive. Refrigeration will only slow down its growth.  Some sort of acid is necessary to prevent the C. Botulinum spores from “germinating” and releasing their deadly toxin.

Food infected by botulism doesn’t look or smell different from safe food. The same danger applies to storing chopped ginger in oil.

“At least four outbreaks of botulism associated with garlic in oil mixtures have been reported in North America in the late 1980s and 1990s. Outbreaks in 1991 (California) and 1999 (Florida) were associated with garlic in oil prepared in the home.” ^[7]Harris, Linda J. Garlic: Safe Methods to Store, Preserve and Enjoy. University of California Agriculture and Natural Resources. ANR Publication 8568. October 2016. Page 3.

A 1989 botulism outbreak was caused by storing garlic in olive oil product out of refrigeration. Heating the food being made with it did not provide any safety:

“A botulism outbreak in 1989 was associated with a garlic-in-olive oil product that had been stored at room temperature (Morse et al., 1990). The implicated product was prepared by mixing chopped garlic, ice water, and extra virgin olive oil and was labeled “keep refrigerated” in small print. The index patient had stored the product at room temperature for approximately three months before opening it, and then placing it in the refrigerator. He had used small quantities in cooked items before using it to prepare garlic bread. The garlic bread was wrapped in aluminum foil and heated at 300°F (149 C) for 20 min before serving. Three individuals became ill with botulism.” ^[8]Palumbo, Mary and Linda J. Harris. Microbiological Food Safety of Olive Oil: A Review of the Literature. UCDavis Olive Center. 2011. Page 7.

For a safe procedure for storing garlic in oil, as well as other garlic preservation tips, see this excellent publication with lab safety-tested recommendations by Linda J. Harris from the University of California: Garlic: Safe Methods to Store, Preserve and Enjoy.

When buying commercial “garlic in oil” products, look on the label for an acid (typically something such as vinegar or citric acid) being amongst the ingredients, which would make it safe.

Frozen Garlic

You can buy garlic frozen in small disks of about 5 g (.18 oz) each. The garlic is puréed; you just pop a portion out of the plastic package and use. Each portion is separate from the other for ease of use. Each portion is equivalent to 1 medium clove of garlic, peeled and minced.

History Notes

The best guesses on garlic’s origin place it in the south-west Asian steppes. Garlic was used by the Egyptians, Greeks and Romans. The Bible mentions the Hebrews eating garlic in Egypt. The Romans used it a lot, but some considered it vulgar and common. The Romans almost certainly introduced it to Britain, as it was a staple in their soldiers’ diet.

Literature & Lore

“And, most dear actors, eat no onions nor garlic, for we are to utter sweet breath; and I do not doubt but to hear them say, it is a sweet comedy.” — Bottom. A Midsummer Night’s Dream. Act IV, Scene II. Shakespeare.

The use of garlic is forbidden to Brahmins and Jains in India on religious and cultural grounds; they use Asafoetida as a substitute.

Language Notes

Our word garlic comes from the Anglo-Saxon word “garleac.” “Gar” meant spear, presumably referring to its spiky stalks, and “leac” meant leek.

Sources

Ross, Graham. “Garlic-in-oil”. Health Canada, November 2002.

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• Bottled Garlic
• Colorado Black Garlic
• Elephant Garlic
• Garlic Flakes
• Garlic Granules
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• Garlic Scallions
• Garlic Scapes
• Green Garlic
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