Wild Strawberry Sauce

This is an uncooked butter sauce in the hard-sauce family, with crushed berries beaten in a few at a time so the fat never breaks. The slow addition is the whole technique.

• Pulverized sugarA finely ground sugar, closest today to confectioners' or powdered sugar rather than granulated. Modern boxed versions contain a little cornstarch, which is harmless here.
• Add the berries slowlyTwo or three crushed berries at a time, fully beaten in before the next go in, keeps the butter from separating under the load of juice. Dumping the cup in at once gives a curdled, weeping sauce.
• Butter temperatureCool room temperature, around 65F, is right. Softened past that the sauce will not hold air and will slump on the plate.
• Wild strawberriesFragaria virginiana berries are small, intensely perfumed and much less watery than cultivated fruit. Cultivated strawberries substitute acceptably, but hull and chop them fine and expect a wetter, paler sauce; alpine or fraises des bois are the closest match.
• Salt and butterButter of the period was often farm butter, salted or fresh depending on the household. With modern unsalted butter, a pinch of salt sharpens the fruit.
• YieldThe recipe gives none; the quantities make well over a cup of sauce, enough for several servings spooned over dessert.
• Serving and holdingChill until firm and serve cold; it softens fast at the table. It is a raw dairy-and-fruit mixture, so keep it refrigerated and use it within a day or two, when the berry flavor is still bright.
• What to serve it withJunket is a rennet-set milk pudding, rarely made now; the sauce works the same way on panna cotta, plain baked custard, or a slice of pound cake.