As the milk mixture heats to 170°, be sure to stir gently and occasionally; if you stir too vigorously or too frequently (more than every few minutes), the curds may not separate as effectively from the whey. And don't stir after the milk mixture reaches 170°, or the cheese will become grainy and thin. If your kitchen sink has a gooseneck faucet, it might be difficult to hang the cheesecloth bag on it. If so, lay a long wooden spoon across one corner of the sink, and hang the bag on the handle.
1 gallon 2% reduced-fat milk
5 cups low-fat buttermilk
1/2 teaspoon fine sea salt
How to Make It
Line a large colander or sieve with 5 layers of dampened cheesecloth, allowing the cheesecloth to extend over outside edges of colander; place colander in a large bowl.
Combine milk and buttermilk in a large, heavy stockpot. Attach a candy thermometer to edge of pan so that thermometer extends at least 2 inches into milk mixture. Cook over medium-high heat until candy thermometer registers 170° (about 20 minutes), gently stirring occasionally. As soon as milk mixture reaches 170°, stop stirring (whey and curds will begin separating at this point). Continue to cook, without stirring, until the thermometer registers 190°. (Be sure not to stir, or curds that have formed will break apart.) Immediately remove pan from heat. (Bottom of pan may be slightly scorched.)
Using a slotted spoon, gently spoon curds into cheesecloth-lined colander; discard whey, or reserve it for another use. Drain over bowl for 5 minutes. Gather edges of cheesecloth together; tie securely. Hang cheesecloth bundle from kitchen faucet; drain 15 minutes or until whey stops dripping. Scrape ricotta into a bowl. Sprinkle with salt; toss gently with a fork to combine. Cool to room temperature.