Lemon Puffs

This is an eighteenth-century sugar-paste biscuit rather than a soft meringue: the ratio of sugar to egg white is high enough that the mixture is shaped by hand or piped, not spooned. The hinge is the oven, which must be cool enough to dry the puffs without colouring them.

• Double-refined sugarThe whitest, hardest loaf sugar of the day, beaten and sieved fine at home. Use caster or superfine sugar; a pound and a quarter is about 2 3/4 cups.
• The ovenThe original gives neither temperature nor time. A period 'moderate' oven was hotter than these puffs want; to dry them without colouring, bake low, in the region of 275-300F, until firm and still pale, which may take upwards of 45 minutes.
• Beating for an hourWith a stand mixer, whip the whites to firm peaks and then beat in the sugar and zest until the paste is smooth, glossy and holds a sharp edge, about 10-15 minutes. The hour in the original reflects hand beating.
• The consistencyThree whites to more than a pound of sugar gives something close to a stiff royal icing, not a pourable batter. Expect to pipe it or roll it into small shapes; if it is too stiff to work, a teaspoon of extra white brings it back.
• The lemon rindTake only the yellow zest, on a microplane, and rub it into the sugar before the whites go in. The oil released that way flavours the whole mass; pith makes the puffs bitter.
• Paper and tin platesBaking parchment on a flat sheet replaces the oiled paper and tin plates. The instruction not to lift them until cold still holds: warm sugar paste tears, cooled paste releases cleanly.
• Yield and keepingAbout three to four dozen small puffs, depending on how they are shaped. Store airtight the moment they are cold, as they draw damp from the air and go sticky within a day in a humid kitchen.