Horseradish

A two-ingredient preparation whose success depends almost entirely on the freshness of the root and how quickly you work. Ranhofer gives no quantities, so treat it by feel.

• Work fast, and away from your faceGrating horseradish releases volatile isothiocyanates the moment the cells rupture; the fumes are genuinely eye-watering in a closed kitchen. Grate near an open window or in a food processor with the lid on, and let it settle a moment before opening.
• The soakRanhofer gives no reason for the few minutes' soak after washing; the likeliest purpose is to loosen grit from the crevices of the root rather than to soften it. Peel the outer skin and any greenish or woody core, which is bitter and fibrous.
• Heat and acid are the switchThe pungency peaks a minute or two after grating and then fades. If you want it to stay sharp, add a teaspoon of vinegar or lemon juice once it has reached the heat you want; the acid stops the reaction. Adding it immediately gives a milder sauce.
• CreamRanhofer specifies neither the type nor the amount, only 'a little cream,' added until the mass is thick enough to lift with a fork; unwhipped heavy cream added by the spoonful, on the order of a couple of tablespoons per cup of grated root, will do it. Lightly whipped cream folded in gives similar body with a lighter texture.
• Quantity and yieldRanhofer gives no quantities. A single large root grated will make a generous side dish for a table of several, served with boiled beef, ham, tongue or smoked fish.
• KeepingMade with cream it should be eaten the same day. Plain grated horseradish packed in vinegar in a sealed jar keeps a few weeks refrigerated, though it loses bite steadily.
• Prepared horseradish as a substituteBottled prepared horseradish is already acidified and salted; drain it well before adding cream and expect a flatter, more uniform heat than the fresh root gives.