Although commonly defined as an herb, sorrel is part of the buckwheat family. It was used by the Greeks and Romans to help digestion. It was also wrapped around meat to help tenderize it. During the Middle Ages, before citrus fruit was brought to Europe, folks used this green herb to add a sour punch to dishes. Once citrus fruit reached Europe, poor sorrel was cast aside. Only recently has this citrus-flavored herb been gaining popularity.
Its tart flavor and tenderizing capabilities come from a compound called oxalic acid, which can also be found in spinach and black tea.
Your best bet is checking your local farmer’s market for sorrel starting in mid-May. Its leaves can either be shaped like a shield or rounded. The color can range from pale to dark green and range from 2 to 12-inches in length. Keep your eyes peeled though, sometimes the young leaves are tossed together with the salad greens. As the herb ages, the acidic flavor becomes stronger.
Varieties also vary in sourness with Garden and Belleville being the strongest flavored, while Dock sorrel is one of the mildest varieties.