Description
Homemade yogurt is surpringly easy to make and a great way to extend it’s shelf life.
Ingredients
8 cups milk (any type, see note)
1/2–1 cup heavy cream (optional)
2 Tablespoons Store bought or home-made Yogurt with live active bacteria (see note)
Instructions
1) Fill a large pot 1/2 full of water, submerge your storage containers and any utenisiles you plan to use (tongs, heat proof spatulas, whisk, or measuring cup with spout, large spoons). Bring this pot of water to a boil. Dip your thermometer probe into the boiling water for a couple of seconds. Remove all utensiles from the pot (I use tongs for this) and transfer them to a clean towel on the counter to air dry. Meanwhile:
If Using an InstaPot to Make Yogurt
Make sure all parts are clean, including the lid and gasket.
Pour the milk into the inner pot. Cover it but leave the vent open. Set the Instapot to “Yogurt” and adjust to the highest position “Boil”. It will begin to heat the milk. This will take about 1 hour. It will beep and turn off when it has “sufficiently” heated. Open the Instapot (it may not be actually boiling), stir the milk and either use your probe thermometer to check the temperature or (if you don’t have one, and I highly recommend you do) visually inspect that the milk is actively steaming. It should be 180 F or higher. You may need to extend the heating time for another 5 or 10 minutes.
Now, pour about 1 cup of milk into a liquid measuring cup and remove the inner pot and place it on the counter or on your burner with the burner off to expedite cooling. Let the milk cool back down to 110 F. This will take about another hour. If you want to speed it up, you can place the pot into a larger pot with ice water and stir the milk occasionally.
The 1 cup of milk that you set aside in the measuring cup will cool faster than the large pot. Once that has cooled to 110 F, stir the yogurt into the 1 cup of milk to inoculate it, and let it sit while you wait for the rest of the milk to reach the target temperature.
When the large pot of milk has reached 110 F, stir in the cup of inoculated milk. Place the milk back into the InstaPot, cover it the vent open, and set it to “Yogurt” for 4-10 hours. The longer it sits the tangier it will be.
If Using the Stove Top:
Pour the milk into a pot (approx 4 quart size) with a lid. If you have a ceramic enameled cast iron brazier or dutch oven, that will work the best as it maintains a warm temperature over a longer period of time. Cover the pot and bring it to a low simmer over medium heat. If you boil the milk over high heat it will likely scald on the bottom. Check the milk every 5-10 minutes, stirring gently and checking the temp. If you do not have a probe thermometer, see note below. When it reaches 180 F, remove the milk from the heat.
Now, pour about 1 cup of milk into a sterilized liquid measuring cup and set aside. Let the milk in the pot cool back down to 110 F. This will take about another hour depending on the pot used. If you want to speed it up, you can place the pot into a larger pot with ice water and stir the milk occasionally.
The 1 cup of milk that you set aside in the measuring cup will cool faster. Once that has cooled, stir in the yogurt and let it sit while you wait for the rest of milk to cool.
When the large pot of milk has reached 110 F, stir in the cup of milk that you inoculated with yogurt bacteria. Cover the pot. Place it in a warm place (in front of sunny window, on your hearth, or a warm but not hot oven that has been turned off) or if you don’t have any of those things, wrap the covered pot in a couple of bath towels to insulate it. Let this inoculated milk sit for 6-12 hours. The longer it sits the tangier it will be.
3) Store your yogurt in the fridge for up to 14 days.
Home-made yogurt in the Instapot.
After 6-12 hours, the milk will be thick. You should be able to lift a spoonful out and it will maintain its shape. You can either strain it through a fine mesh sieve for Greek Style yogurt (several hours or overnight in the fridge) or whisk it vigorously to smooth out any lumps and transfer it right away to your sterilized containers. Cover and refrigerate the yogurt for up to 14 days. It will continue to get tangier in the fridge.
Notes
Selecting Milk For Yogurt
You can use any kind of lactose milk: cow, sheet, goat, etc. You can use skim, lowfat, whole milk and cream. My preferred combo is 8 parts whole milk and 1 part heavy cream. You can substitute about 25% of milk for milk alternatives like soy or coconut milk without making changes to this recipe.
It is possible to make yogurt from soy or coconut milk and other milk alternatives using probiotic capsules or yogurt cultures but it behaves a little differently and this recipe is not really applicable to milk alternatives. Cultures for Health is a great site for purchasing all different cultures and has information about “Alternative Milks for Making Yogurt“.
Selecting your Yogurt Culture
Your yogurt starter should include lactobacillus bulgaricus and streptococcus thermophilis. The easiest method is to use your favorite store-bought yogurt as your inoculum. You can then use your own batch of yogurt to inoculate the next batch that you make. Store-bought yogurt is readily available. You just need to make sure that it is unflavored and that it “contains live active bacteria” versus “is made with live active bacteria”.
You can also use heirloom yogurt starters, gifted from friends or purchased by specialty stores like Cultures for Health. These starters may be specific to a certain geographic region or family. If you strain your yogurt through a cheesecloth or towel, you can dry the towel without washing it (just a quick rinse with cold water) and then use it to inoculate milk.
You can use probiotic capsules that contain lactobacillus bulgaricus and streptococcus thermophilus. Other yogurt-making bacteria include lactococci, lactobacillus delbrueskii, lactobacillus fermentum, lactobacillus casei, and lactobacillus brevis. Probiotic capsules also contain other strains of bacteria that are known to survive the human digestive system and provide health benefit to us but are not known to make the best tasting or creamiest yogurt: bifidobacteria (from breast milk- acidifies the stomachs of infants before stomach acid is produced), lactobacillus plantarum (makes fermented pickles), lactobacillus acidophilus (native to the intestinal tract) and Lacticaseibacillus rhamnosus (native to the urogenital tract). If you use probiotic capsules make sure that they contain primarily probiotics that turn milk into yogurt and be aware that the end product will be healthful but perhaps not as delicious as it could be if you used only yogurt-making species.
If you do not have a probe thermometer:
If you do not have a probe thermometer, you will need to use your senses to check the milk’s temparature. At 180 F, the milk will be steaming even after you stir it. When left alone, it will be slowly moving in the pot from convection, but not boiling.
Liquid at 110 F is the temperature of an extra-hot hot tub. Check the milk by touch without contaminating it. Wash your hand very thoroughly. You know, sing the Happy Birthday Song, hot water, lots of soap, scrub scrub scrub. Then you either can dip your knuckle in it (not your finger because bacterial is hard to completely remove from under your fingernails). Or you can pour a spoonful over the back of your very clean hand.
I highly recommend having a probe thermometer. Mine is one of my most used kitchen tools.