Cottage Cheese

This is the standard pre-refrigeration method for turning milk that has gone off into food, and it depends on a milk supply that no longer exists. The instructions as printed have no step that would make the finished curd safe.

• "Sour milk" is not spoiled milk from the fridgeThe recipe assumes raw milk left in a cool larder, where native lactic acid bacteria dominate and clabber it into a clean, firm, tart curd. Pasteurized milk has had that flora reduced; left out, it is colonized by whatever spoilage organisms reach it, and it tends to putrefy rather than clabber. Smell and appearance are not a reliable guide to which has happened.
• 100°F is an incubation temperature, not a kill stepWarming to about body heat is done to help the curd contract and release whey. It sits in the middle of the growth range for Salmonella, E. coli O157:H7 and Listeria, all of which are associated with raw milk. The quart of hot water poured over the curd washes it; it does not pasteurize it.
• Draining at room temperatureHanging the bag "until all whey has drained off" can take several hours. The curd is moist and unrefrigerated for that whole period — the conditions under which any surviving organisms multiply fastest.
• Cream and butter add a second unheated ingredientCream and butter are added at the end -- The cream goes in uncooked, and depending on source may have been unpasteurized; the butter is only melted, which is not a heat treatment. Nothing after this point is cooked.
• What the original would have yieldedThe recipe gives no quantity of milk; the quart named is the hot rinse water. A curd of this kind yields a modest amount of cheese from a quantity of milk that would otherwise have been discarded.
• If you want cottage cheeseUse a current recipe built on pasteurized milk and a measured acid or a commercial culture, with the holding and chilling temperatures specified.