Pineapple Ice Cream

A shorthand entry that assumes you already have the book's two base custards in hand. The pineapple itself is the part that needs attention.

• The hinge: fresh pineapple and dairyFresh pineapple contains bromelain, a protease that breaks down milk and egg proteins, and it will thin a custard base and can leave it grainy or faintly bitter. Heat the juice and pulp to a simmer for a couple of minutes before adding it, or use canned pineapple, which is already heat-treated.
• Which base"French" ice cream in this period means a cooked egg-yolk custard; "Philadelphia" means cream and sugar with no eggs. Against a household batch of base, two cups of fruit is a substantial addition.
• Add it cold, and lateChill the cooked juice and pulp thoroughly and stir it into the cold base just before churning. Warm acidic fruit dropped into a cream base will curdle it.
• SweeteningPineapple is acidic enough that the base will taste flat if you sweeten only for the dairy. Taste the combined mixture before freezing and expect to add 2 to 4 tablespoons of sugar; it should taste slightly too sweet cold, since freezing mutes sweetness.
• Texture from the pulpTwo cups of juice and pulp adds a lot of water, which freezes hard and icy. Draining some juice, or reducing it by a third before chilling, gives a smoother result.
• FreezingFor a crank freezer, pack in three parts crushed ice to one part rock salt and turn until the dasher stiffens, then remove the dasher and ripen the packed can an hour under ice and salt. In a modern machine, churn 20 to 25 minutes and firm in the freezer for two hours.
• YieldDepends on the base you start from; a quart of base plus the fruit will give roughly 1 1/2 quarts churned.