Before we begin let’s discuss some side notes. Do not ignore this advice. We don’t want you losing cultures!
Please do not add probiotic capsules or powders during activation batches. We recommend that you don’t do it at all because it can and often does kill the culture over time, but definitely do not do it during activation.
If you are planning to make yogurt with raw milk, please refer to our raw milk yogurt guide. The raw milk guide does not give you all the information you need to make your yogurts properly, so come back here when you’re done over there. We recommend activating your yogurt cultures with pasteurized milk: this is typically 3 batches of yogurt. Your cultures have been dormant, so it’s gentlest to give the little guys a chance to wake up and thrive rather than forcing them to struggle through their jet lag.
The first three batches of your yogurt need to be done back-to-back (one right after the previous batch, with no more than 24 hours between batches).
Activating The Culture: Thermophilic Yogurt
Activating The Culture
Slowly heat 1/2-1 cup of pasteurized milk to 180 degrees Fahrenheit. Use the lowest setting your stove has, or a crockpot on the lowest setting. To prevent the milk from sticking to the bottom of the pan, you can rub an ice cube along the bottom or you can pour a bit of water into the pan, swirl, and pour the excess off. Add the milk as usual.
Remove the milk from the heat and allow to cool to 95-105 degrees Fahrenheit.
Pour cooled milk into a container and add half the packet of starter culture. Mix well. Put the other half of the packet in the freezer as a backup.
Cover the mixture and incubate at 95-105 degrees for 5-12 hours in a yogurt maker or similar appliance.
Check after 5 hours to see if it has set. If it has not set, leave it for up to 12 hours, checking every 30-60 minutes. Once it has set, or at the end of 12 hours (whichever comes first), turn off the yogurt maker and allow it to cool for 2 hours.
Refrigerate the yogurt for at least 6 hours.
For the remaining activation batches, you will repeat steps 1-6, except you will use 1 tablespoon of the yogurt you just made in place of the powdered culture you received in the mail.
Making Yogurt On The Regular
Spoiler Alert: You can’t do this until at least 3 activation batches are complete and your culture is setting up properly
Slowly heat 1 quart of pasteurized milk to 180 degrees Fahrenheit. Use the lowest setting your stove has. To prevent the milk from sticking to the bottom of the pan, you can rub an ice cube along the bottom or pour a bit of water into the pan, swirl, and pour the excess off. Add the milk as usual. Alternately, UHT milk.
Remove the milk from the heat and allow to cool to 95-105 degrees Fahrenheit.
Add 4 Tbsp. (1/4 cup) of yogurt from the previous batch and mix well. The ratio here is one tablespoon of culture per cup of milk.
Pour the milk into the container(s), cover the mixture, and culture for 5-8 hours at 95-105 degrees Fahrenheit. After 5 hours, check the yogurt frequently by tilting the jar gently. If the yogurt moves away from the side of the jar in one mass instead of running up the side, it is finished culturing. Some yogurts will need longer than 8 hours, so if it isn’t set at 8, give it some more time.
Once it has set, allow it to cool for 2 hours.
After 2 hours, refrigerate it for at least 6 hours before eating.
Don’t forget to save a couple tablespoons for culturing the next batch, plus a couple to freeze as backups!
Should you have any problems with your yogurt starter, please email us prior to throwing the starter away.
We can probably help you save it.
In some cases, your culture will be a bit sluggish when you first activate it. You’ll know this happened if it is too thin or runny, or if it has some lumps and some milk. Just keep keepin’ on, and it should be acting normally by the the third batch. Your second and third batches will use a ratio of 1 tablespoon of yogurt from the last batch to 1 cup of fresh milk. Even if your batch is runny, overfermented, or otherwise weird. This is the same ratio you’ll use once your culture is activated. Don’t forget to check out our FAQ for answers to common issues!
You can skip the pasteurization step entirely if you use UHT (ultra-pasteurized) milk, and simply heat your milk to 100F. Sabrina prefers to activate all 3 batches with one cup of milk per batch; Allie never uses more than half a cup for activation batches.
If you choose to incubate in a cooler or in the oven with the light turned on (wrap your closed container in blankets first!), this process will take up to 24 hours. You can just set an alarm and come back in 24, if you like. You may also use the “mead method” in your Instant Pot, which does all 3 activation batches in one continuous cycle for 36 hours. This is Allie’s favorite activation method these days, and it was developed by our lovely community member, Tara S.
You can eat your yogurt any time after it’s made, except what you save for the next batch. Refrigerating helps set the yogurt, but if you want to eat some of your warm yogurt, dew eet! In some of our houses, kids claim the first bowls while the yogurt is still warm.
Tips and Tricks
We like to ferment our yogurt in pint or quart-sized mason jars. This makes it easier once it’s done culturing. Just put lids on the containers and set on the counter to cool for the 2 hours. There is no need to transfer to another container at the end of the ferment. We find that the quart and pint sized jars fit very well in the DASH bulk yogurt makers. To make serving size portions, the half-pint or pint sized jars are perfect and fit very well in an instant pot over the rack. If using an instant pot, the pint sized fit perfectly on top of the rack!
Never buy yogurt again! Heirloom yogurt can be cultured over and over again. This means that if you take care of your culture, you never have to buy yogurt again! To keep your culture viable, you must try to make your next batch of yogurt within 5-7 days. After that time frame, the culture can start to die off and may not be healthy enough to re-culture. As an aside, people still make Trotsky’s yogurt. Heirloom yogurts can seriously reculture milk for centuries.