Horseradish

A plain preparation of fresh horseradish root, meant as a garnish rather than a sauce. The whole difficulty is in the grating and in how fast the flavour fades.

• Ventilate before you grateGrating horseradish releases allyl isothiocyanate, which is far more aggressive to the eyes and nose than onion. Work near an open window or an extractor hood, and turn your face away when you first uncover a food processor bowl.
• Peel, then soakSoak, then peel -- The hour in cold water freshens a root that has been out of the ground a while. The recipe does not say so, but most modern cooks peel off the tan outer layer and cut away any woody core before grating.
• Use it within the hourThe pungency peaks a couple of minutes after grating and then declines steadily as the volatile oils escape. Grate immediately before serving, not in advance.
• Acid fixes the heatAcid checks the heat -- If you need to hold it, tossing the shreds with a spoonful of vinegar or lemon juice slows the reaction and helps hold the heat near the level it has reached. Waiting several minutes before adding acid gives a fiercer result.
• QuantityA root of about 6 inches and an inch thick yields well under a cup of shreds. Very little is eaten per person; the recipe itself specifies no quantity.
• StorageUnpeeled root keeps two or three weeks wrapped in the refrigerator. Grated horseradish left loose in the refrigerator loses most of its character within a day and turns grey-brown.
• Beyond beef and fishThe same shreds are good on boiled potatoes, smoked trout, beetroot, and in a spoonful of whipped or sour cream if a sauce is wanted rather than a garnish.