Adapted from Maureen Abood
I use an heirloom starter that a friend of the family brought to the States from Yazd, Iran in 1998. If you are using commercial yogurt as a starter, make sure you purchase plain, not vanilla, and look for “live, active cultures” on the package. Typically a thinner, European, and not “Greek” yogurt works better, but some have suggested success with Greek-style yogurts such as Fage Total. After making a batch, set aside a half-cup of yogurt (store in the fridge uncovered) to use as a starter for the next batch.
The recipe that follows is lengthy and full of details I’ve learned over many years of making yogurt on a weekly basis; don’t let this deter you! Making yogurt is really very easy; it is a simple 4-step process:
- Heat the milk to 180F, or to just below the boiling point.
- Cool the milk to 110-120F – a thermometer is good, but not essential.
- Inoculate the milk with the yogurt culture (“starter”).
- Incubate for several hours, until thickened.
½ gallon (2L) dairy milk (skim, 1%, 2%, or “vitamin D” whole milk)
¼ cup (60ml) yogurt, at room temperature. This is your starter.
Heavy saucepan, 3-quart (3L) or larger
Candy or Instant-Read Thermometer (optional)
Porcelain or Ceramic Bowl (2 or 3 quart) to incubate the yogurt (optional, in case you don’t wish to use your saucepan)
Kitchen Timer (optional)
Fahrenheit-Celsius Temperature Conversions:
180-190F = 82-88C
110/115/120F = 43/46/49C
Prepare the equipment. Start by removing your starter from the fridge and setting it aside. Scrub the pan, its lid, the spoon, and the whisk very well, and then rinse them with very hot water to make sure everything is free of any grease or dirt. Or, just run the equipment through the dishwasher. Rinse it well with cold water, or run an ice cube over the inside, until the pan is quite cold. Dry well. Chilling the inside of the pan will stop the milk sugars from sticking to the pan for easier clean-up later. If you will be using a gas oven as an incubator, turn on the light and turn the oven to its lowest temperature. As soon as temperature is reached, turn the oven off, leaving the light on. It will cool down during the rest of the steps to the required warm & cozy environment.
Heat the milk. Add the milk to the pan, cover, and turn the stove to medium heat. Bring to just below a boil (180-190F); it should take about 10-15 minutes to reach this stage. Stir the milk occasionally, taking care to keep your spoon clean. Setting a timer can help avoid milk spilling over onto the stove. Stay nearby, because the milk will froth up, and as it begins to boil it will rise up swiftly in the pan. Remove from heat immediately.
Cool the milk. Pour the milk into the container in which the incubation will happen (alternatively, leave it in the saucepan). Let the milk cool down to 110-120F*. You can place your container in a large bowl of ice to help it cool down much faster. Without the ice, expect 40-60 minutes for cooling time; with the ice, 5-8 minutes. Whisking the milk during the cooling period will help cool it faster and will discourage the formation of a skin on the final product. If you are not using a thermometer, the equivalent is when your clean pinky finger can just withstand being held in the milk for ten seconds. Using a timer and checking the temperature every so often can help avoid the milk getting too cool. If the milk cools below 110F, gently warm it up to 110-120F. If in this process of reheating, the temperature goes above 120F, wait again until it comes back down to 110-120F.
Add the starter. Remove the thermometer if you’ve used one. Spoon a few tablespoons of the milk into the yogurt starter to temper it, and add it to your bowl or pot of milk. Very gently stir it into the bowl or pot of milk. If you haven’t whisked in the previous step, you will notice a skin forms on the surface of the milk; this can be stirred right in with the starter, or spooned out.
Rest the milk (incubation). Cover the bowl or pan with a lid or a plate. Set it aside, undisturbed, in a warm spot for anywhere from 6 to 30 hours*. An ideal incubator is a gas oven with only the light on to keep it warm and cozy. An alternative incubation spot is the corner of the kitchen with several towels and blankets over it. It needs to remain absolutely undisturbed during incubation.
Chill the yogurt. Remove the pot or bowl from the oven. The milk will have thickened into yogurt, probably with liquid whey on the top. Place, undisturbed as of yet, into the refrigerator for 24-72 hours to further set the yogurt before eating or straining to thicken, if desired. If you wish to strain your yogurt for thickness (“Greek” yogurt), you can use a special yogurt strainer, an inexpensive nut-milk bag, or cheesecloth.
Store, uncovered, in the refrigerator, for up to 2 weeks.
*I like yogurt to have an acidic, fermented taste. Therefore, I add the starter at 120F and rest it for at least 20 hours. For a mild flavor, add the starter at 110 or 115F and rest it for 6-8 hours.