Brussels sprout

Although native to the Mediterranean region with other cabbage species, Brussels sprouts first appeared in northern Europe during the 5th century, later being cultivated in the 13th century near Brussels, Belgium, from which they derived their name.[1][2] Its group name Gemmifera (or lowercase and italicized gemmifera as a variety name) means gemmiferous (bud-producing).

Forerunners to modern Brussels sprouts were probably cultivated in Ancient Rome. Brussels sprouts as they are now known were grown possibly as early as the 13th century in what is now Belgium. The first written reference dates to 1587. During the 16th century, they enjoyed a popularity in the southern Netherlands that eventually spread throughout the cooler parts of Northern Europe.

Brussels sprouts grow in temperature ranges of 7–24 °C (45–75 °F), with highest yields at 15–18 °C (59–64 °F).[2] Fields are ready for harvest 90 to 180 days after planting. The edible sprouts grow like buds in helical patterns along the side of long, thick stalks of about 60 to 120 cm (24 to 47 in) in height, maturing over several weeks from the lower to the upper part of the stalk. Sprouts may be picked by hand into baskets, in which case several harvests are made of five to 15 sprouts at a time, or by cutting the entire stalk at once for processing, or by mechanical harvester, depending on variety. Each stalk can produce 1.1 to 1.4 kg (2.4 to 3.1 lb), although the commercial yield is about 900 g (2 lb) per stalk.[2] Harvest season in temperate zones of the northern latitudes is September to March, making Brussels sprouts a traditional winter-stock vegetable. In the home garden, harvest can be delayed as quality does not suffer from freezing. Sprouts are considered to be sweetest after a frost.[3]

Brussels sprouts are a cultivar group of the same species as broccoli, cabbage, collard greens, kale, and kohlrabi; they are cruciferous (they belong to the family Brassicaceae; old name Cruciferae). Many cultivars are available; some are purple in color, such as 'Ruby Crunch' or 'Red Bull'.[4] The purple varieties are hybrids between purple cabbage and regular green Brussels sprouts developed by a Dutch botanist in the 1940s, yielding a variety with some of the red cabbage's purple colors and greater sweetness.[5] In the 1990s, Dutch scientist Hans van Doorn identified the chemicals that make Brussels sprouts bitter. This enabled Dutch seed companies to cross-breed archived low-bitterness varieties with modern high-yield varieties, over time producing a significant increase in the popularity of the vegetable.[6]

Raw Brussels sprouts are 86% water, 9% carbohydrates, 3% protein, and negligible fat. In a 100 gram reference amount, they supply high levels (20% or more of the Daily Value, DV) of vitamin C (102% DV) and vitamin K (169% DV), with more moderate amounts of B vitamins, such as folate and vitamin B₆ (USDA nutrient table, above right); essential minerals and dietary fiber exist in moderate to low amounts (table).

Brussels sprouts, as with broccoli and other brassicas, contain sulforaphane, a phytochemical under basic research for its potential biological properties. Although boiling reduces the level of sulforaphane, steaming, microwave cooking, and stir frying do not cause a significant loss.[11]

Consuming Brussels sprouts in excess may not be suitable for people taking anticoagulants, such as warfarin, since they contain vitamin K, a blood-clotting factor. In one incident, eating too many Brussels sprouts led to hospitalization for an individual on blood-thinning therapy.[12]

Brussels sprouts prepared for cooking in a wood-fired pizza oven

The most common method of preparing Brussels sprouts for cooking begins with cutting the buds off the stalk. Any surplus stem is cut away, and any loose surface leaves are peeled and discarded. Once cut and cleaned, the buds are typically cooked by boiling, steaming, stir frying, grilling, slow cooking, or roasting. To ensure even cooking throughout, buds of a similar size are usually chosen. Some cooks make a single cut or a cross in the center of the stem to aid the penetration of heat. The cross cut may, however, be ineffective, with it being commonly believed to cause the sprouts to be waterlogged when boiled.[13]

Overcooking renders the buds gray and soft, and they then develop a strong flavor and odor that some dislike for its garlic- or onion-odor properties.[9][14] The odor is associated with the glucosinolate sinigrin, a sulfur compound having characteristic pungency.[14] For taste, roasting Brussels sprouts is a common way to cook them to enhance flavor.[14][15] Common toppings or additions include Parmesan cheese and butter, balsamic vinegar, brown sugar, chestnuts, or pepper.

Wikimedia Commons has media related to Brassica oleracea var. gemmifera.

• Brassica oleracea gemmifera – Plants For a Future database entry