Calories in Leeks, bulb and greens, root removed

What makes leeks so powerful?

Leeks (Allium ampeloprasum) carry a unique botanical distinction: they are the only major allium that does not form a true bulb. Instead, the edible "bulb" is actually a tightly packed pseudostem formed by overlapping leaf sheaths. When cut, leeks release volatile sulfur compounds like allicin, generated when the enzyme alliinase reacts with the precursor alliin. Unlike onions, leeks contain a higher proportion of specific fructans—chains of fructose molecules that act as prebiotic fiber. These fructans are responsible for the vegetable's subtle sweetness when cooked slowly, as they break down and caramelize without the sharp pungency of onion-derived sulfur compounds. Historically, the leek's layered structure made it a symbol of resilience, famously adopted by the Welsh. According to legend, King Cadwallon ordered his soldiers to wear leeks on their helmets during a 7th-century battle against the Saxons to distinguish friend from foe in the fields. Today, this structural quirk means leeks require meticulous cleaning, as soil routinely gets trapped between the sheaths during the blanching process, where farmers mound dirt around the base to keep it white and tender.