Peach Sherbet

A plain fruit sherbet from the era of the hand-cranked ice cream freezer, with one element that no longer passes muster: the egg white goes in raw and the mixture is never heated at any stage.

• The raw egg whiteNothing in this recipe reaches a temperature that would kill Salmonella; freezing preserves bacteria rather than destroying them. An uncooked white stirred into a cold fruit base and frozen carries the same risk as raw egg in any other unheated preparation, and sherbet is often served to children and the elderly. Use a current recipe if you want to make peach sherbet.
• Why the white is there at allThe albumen is doing mechanical work, not flavour work. Its proteins interrupt ice crystal growth and hold a little air, which is exactly what the note about "more creamy and less fluffy" describes: beaten white would inflate the mixture, unbeaten white simply softens the texture.
• "Freeze" means a churnIn this period the instruction assumed a bucket freezer packed with cracked ice and rock salt, cranked until the paddle stiffened. Left still in a modern freezer the same mixture sets into a solid block, because there is no dairy fat and very little sugar syrup to keep it soft.
• Peach pulp by volumeA pint of pulp rubbed through a colander takes roughly 1 1/2 to 2 lb of ripe peaches, depending on how much the fibre holds back. The colander, not a blender, was the point: it holds back coarse fibre while leaving the purée slightly textured.
• Sugar is doing structural workThree-quarters of a cup for a quart of liquid is modest by sherbet standards. Sugar depresses the freezing point, so a low-sugar fruit ice freezes harder and scoops worse than a sweeter one; a mealy or underripe peach makes the problem worse still.
• YieldThe finished quantity is close to a quart before churning, which serves six to eight as a small course.