Asparagus is a much-welcomed sign of spring to chefs and foodies. Its true harvesting season only lasts around 2 weeks but here in Canada, asparagus is available year-round.
The difference between green and white asparagus comes in how it was grown. White asparagus does not turn green because it is completely grown underground since farmers mound dirt around it. The sunlight never hits it so it does not produce the green pigment (chlorophyll). Purple asparagus is a particular variety of asparagus. White asparagus requires more labour in planting, growing, harvesting, and packaging so it is more expensive.
Underground, there is a network of nodes and buds from a crown. Energy is stored in the crown and then spears of asparagus shoot up out of the ground from the same crown. When asparagus is picked, more asparagus grow there in the future, however over-cutting can deplete future growth.
Dorothy Duncan, in Nothing More Comforting, shares Canadian asparagus recipes from as early as 1727 (p 22). The history of asparagus goes back to Roman times and asparagus is a Greek word. In parts of Africa, they are grown as ornamental plants.
Asparagus can be blanched, sautéed, steamed, and roasted--served hot or cold. It is also edible raw in salads and shaving paper thin slices like ribbons can be lovely and delicate.
White asparagus is often thicker-stemmed and benefits from peeling, at least the bottom half.
When working with a bunch of asparagus, it is best to snap asparagus spears by hand and allow the stem to break where the natural weak point is. The weak point is where the fibrous and woody base ends and the tender middle part begins. Be careful not to break too high up! The yield will be low. Another option is to consider cutting closer to the base and peeling the bottom portion to remove woodiness.
Consider cutting a tiny end of the base of asparagus and store standing up in a small amount of water (uncovered) for optimum freshness.
Why is asparagus often seen tied in bundles when blanching? It is not necessary, but some chefs like to gently tie asparagus together to avoid causing damage to the spears. It also allows for an easy and delicate removal of the asparagus into an ice bath for cooling. Tongs and other utensils can bend or bruise tender spears.