What Is White Asparagus?
One of the first signs of spring is the abundance of bright green asparagus spears at the grocery store—it's something cooks in the United States look forward to, but in Germany, they look for those spears in a much lighter shade: white. But what is white asparagus?
A German Delicacy
In Germany, white asparagus (weißer spargel) is celebrated (literally) with festivals from April to June. If you've never had white asparagus, it is exactly like green asparagus but without chlorophyll (the green in plants that helps generate oxygen in the photosynthesis process). It has to do with the deliberate harvesting process where it's grown without sunlight. It's sweeter and more tender than the green variety.
Harvesting Asparagus: White vs. Green
White and green asparagus are grown the same way but there's one huge difference in the process. White asparagus stalks are picked before they peek through the soil–they never see the sun. The green asparagus stalks are picked after they break through the soil and are exposed to the sun to develop chlorophyll, which is what makes them green.
To Peel or Not to Peel
The outer layer of white asparagus can be tough and fibrous, which means it's best to peel white asparagus. To remedy this, use a vegetable peeler to remove the woody layer before cooking the same way you would with green asparagus. Peeling the outer layer of white asparagus makes the stalk very tender after it's been steamed, roasted or sauteed.
The Price of White Asparagus
White asparagus is typically more expensive than green asparagus because it's only available a few weeks a year and the growing process requires special attention. That rarity translates to premium prices, but to some people, those sweet stalks are worth it.
White Asparagus Availability
There are select growers that make fresh white asparagus available in the United States, but it's not as common as it is in Germany. Most of the white asparagus that you find online or in the grocery store is packaged in cans or jars.
White Asparagus Nutrition
The nutritional value of white asparagus is not that different from green asparagus. Cooked white asparagus has about double the amount of vitamin C (18.18 mg per cup vs. 9.93 mg) and about half the amount of vitamin A (757.58 IU per cup vs. 1297.74 IU).
The Scent of White Asparagus
Green asparagus is notorious for changing the odor of urine–white asparagus has the same effect. Asparagusic acid is responsible for the odor. Only asparagus (white and green) contain asparagusic acid. When it goes through our digestive systems, it gets broken down into compounds that contain sulfur. It's the sulfur that stinks when it leaves the body. However, according to a study published in the BMJ, only some people with particular genes can smell it.
Cooking White Asparagus
The delicately sweet spears demand kid-glove treatment in the kitchen too. Lay spears flat on a cutting board and peel the bottom two-thirds of each spear with a vegetable peeler. Boil in a large skillet filled with several inches of water until very tender, 10 to 20 minutes. (Don't leave them tender-crisp as you might with green asparagus.)
For an easy dip, stir together 3 tablespoons each of nonfat plain Greek yogurt and low-fat mayonnaise with 2 teaspoons lemon juice, 1 tablespoon chopped fresh dill and a pinch of salt.