It’s a wonderful time of year for garlic lovers, when recently harvested garlic has cured for the requisite two to three weeks and is ready for eating. There are many ways to prep and use garlic in the kitchen to elicit its profound flavours. First, a quick lesson in what makes garlic tick will help to appreciate how to get the most out of the odiferous bulb.
Dr. Eric Block has been studying garlic for more than forty years. His book, Garlic and Other Alliums: The Lore and the Science, brings to life the complexity of allium chemistry. Understanding garlic’s chemistry makes for good conversation at the dinner table or the water cooler. And it may just help your cooking, too.
Imagine the parts that make up nitroglycerin. Separately they’re inert and stable. But when mixed, they react violently. Something similar occurs in garlic when an invading pest or herbivore gnaws its way into the plant’s cell walls. That bite triggers a tripwire that activates the plant’s defense mechanism. Two substances stored separately in thousands of cells in the garlic plant are called into action. When the cell walls are breached by the invader, the enzyme alliinase and the compound alliin instantly react to form allicin. That chemical repels the invading pest, which can’t stand the odour. Allicin accounts for much of the smell and taste of garlic. While pests are repelled, we humans have adapted it into our cooking and medicine. Most of the allicin is created in less than a second. However, additional reactions occur over minutes and hours. Each reaction begets a new chemical reaction, with unique corresponding flavours. Because the chemical composition differs among garlic varieties, their individual tastes and odours also vary.
Understanding garlic’s chemistry makes for good conversation at the dinner table or the water cooler. And it may just help your cooking, too.
The amount of allicin created in preparation for cooking depends on the number of cell walls breached. And that depends on the method used, such as chopping, using a garlic press, or other means.
Each method produces a different texture, flavour, and intensity. Feel free to experiment. Here, in order of strength, are the most popular methods of releasing garlic’s flavours.
Boil unpeeled cloves as directed in a recipe. This releases some mild garlic flavours (very little allicin is created) and, some say, a subtle sweetness. I’m not a fan of boiling garlic.
Peel, smash, and chop coarsely. This produces a small amount of allicin. It works best for garlic bits fried in oil. The browned nuggets are a tasty garnish on soup or salad. Coarsely chopped pieces retain some of the clove’s structure, leaving most cells intact until the dish is served. As the bits are chewed, allicin is released inside the mouth.
Finely chopped garlic is stronger and works better in liquids than fried in oil.
Smashing (mortar and pestle)
Peel, place in mortar, and grind to a paste. This produces a larger amount of allicin, similar to mincing. The paste it produces works well in liquids and makes a good spread.
One of the quickest ways to get the flavour out of garlic is to use a blender. Place the desired number of peeled cloves in a blender and turn on for a few seconds.
Peel, smash, mince, and smash again. This produces the most allicin of any knife-prep method. It works best in liquids.
Pressing (garlic press)
Peel, place in garlic press, and squeeze over a small bowl. This produces more allicin than any knife-based method and protects your fingers from touching the garlic. Most presses these days are self-cleaning: tiny nubs are aligned to poke out the garlic pulp after use. Scrape off any pressed garlic and add to the bowl. Pressed garlic works best in liquids.
Peel, hold clove in two fingers, and grate. This method releases the most allicin and provides maximum garlic flavour. Microplaned garlic works best in liquids. Take care to protect your fingers!
Whatever prep method you use, timing is critical. Once the cells of the clove have been breached, add garlic to the recipe as soon as possible. Unlike most ingredients, the volatile compounds that make up the odour and taste of garlic will quickly dissipate. Dr. Chung-ja Jackson has studied garlic at the University of Guelph and noted that most of the allicin is created within a few minutes. That’s why chef Michael Stadtländer uses garlic immediately after chopping. “I don’t like it sitting around when I’m cooking á la minute.”