Do you like yogurt?
Would you like to learn how to make your own delicious yogurt at home, just the way you like it, without having to buy a yogurt maker?
Up until yesterday, I always bought yogurt at the supermarket – Beatrice, Danone (or Dannon, apparently, as it is known in the States), Breyer’s, Activia, and my latest love, Stonyfield Farms. Then it dawned on me that as a trained microbiologist, it’s probably just as easy as starting a bacterial culture like I routinely do in the lab. Okay okay… don’t worry, you don’t need to have experience working with bacteria to make your own yogurt. I’ll write a more detailed post with step-by-step photos next time, but I’m so excited that I made my own yogurt that I wanted to share this really easy and inexpensive way to make your own yogurt at home.
Making yogurt at home
This sort-of recipe is for a 1/2 gallon (8 cups) of yogurt. You can scale up or down depending on how much you want to make. Properly stored, the yogurt can last for at least a week. You’ll need:
Make sure these pieces of equipment have first been washed with hot water and dried. Otherwise, if they’re dirty with germs and such, you’re providing the bad boys with food and a nice, warm place to grow –> spoiled yogurt –> a batch of yogurt that you’ll have to throw away.
– A pot that holds at least a 1/2 gallon (8 cups) of liquid, which will become your new favourite yogurt.
– A wooden spatula.
– A thermometer that can read from 100 – 180F (~37-82C). I bought a candy thermometer on sale at the grocery store for $4.00. It’s handy because it comes with a clip so I can clip it onto the side of my pot and not have to hold it as the milk is heating.
– A working oven. More on this in a bit.
– 1/2 gallon of milk.
I used whole milk because I love Stonyfield Farm’s whole milk french vanilla yogurt, but I’ve read that lowfat can also be used, or even reconstituted nonfat dry milk.
– 1/3 cup nonfat dry milk, optional.
I added this because I like thick, creamy yogurt and read that the addition of nonfat dry milk a.k.a. milk powder helps make the yogurt thicker. If you don’t use it, you’ll still be able to make yogurt but it will be a bit thinner. Keep in mind that because the yogurt is homemade, it will be slightly thinner than what you buy at the grocery store since no thickeners like cornstarch have been added.
– A yogurt starter.
Think of this as a “seed” for your batch of yogurt. What this means is to make your own yogurt, you’ll first need to introduce a bit of yogurt to the pot of milk. The bacteria in the yogurt will convert the milk into fresh yogurt. Some people buy dry yogurt starter (available in packets), but you can also just buy a small cup of yogurt. Buy as plain and natural a yogurt as you can. I cheated and used the aforementioned Stonyfield Farm whole milk french vanilla yogurt and it still worked, but the main point is to try and avoid using yogurt with fruit as your starter. The extra fruit or toppings might affect the resulting taste, consistency and quality of your yogurt.
1. Pour the milk into the pre-washed, clean pot and mix in the dry milk powder if you are using it. Heat up the milk (and milk powder) to 170-180F (~77-82C), stirring as you do so. Hold the milk at this temperature for 2-3 minutes. Apparently this prepares the proteins in the milk for the magical transformation into yogurt. Avoid heating the milk to higher than 180F/82C because this will ruin your yogurt.
2. Turn off the heat, and cool the milk to 105-110F (~41-43C). I put the pot over a bowl full of cold water to cool it faster. You can probably even use ice to cool it faster still. You want to bring the temperature down so that when you add the yogurt starter, you won’t kill it because the milk is too hot. Once the milk has cooled, add your yogurt starter and stir it into the milk. Some people say to use ~3 tablespoons, some say use the entire cup of yogurt (~6 oz)… I happened to add 3 heaping spoonfuls of yogurt.
3. At this point in time, you can divide your yogurt into cups/bowls/containers (washed first with hot water and dried) for individual servings. I just left it in the pot and figured I could divide it into smaller portions as needed. Incubate your milk and yogurt – this means let the milk/yogurt mixture sit in a warm place where it won’t be disturbed. The more you move it around and jiggle the pot, the less likely it will set. Some ideas for a makeshift incubator are a big cooler with some containers of hot water and towels to keep the environment nice and warm, a hot plate, a heating pad, or an oven. I chose the last option because I didn’t have any of other items. I turned the oven to 350F for a few minutes just to warm it up a bit before I put in my pot of yogurt.
4. How long do you let your yogurt sit? It depends on how tangy you want it to be. I tried 4 hours at the recommendation of a friend, but found it to be a bit mild in taste, almost like tofu pudding (豆腐花) if you’ve ever tried it… which is not entirely a bad thing 🙂
Next time I think I will try letting it sit for closer to 6-7 hours. The longer you let the yogurt sit, the tangier it will be.
5. Test and see if your yogurt has set! You can tilt your pot slightly to check: the yogurt shouldn’t move as you tilt the pot. You can also try scooping out the yogurt like so:
6. However, there is still one last step before you’re done. This fresh batch of yogurt needs to firm up in the refrigerator before it’s ready – I left mine in the refrigerator overnight. Then, dish it out in a bowl and enjoy. I had a bowl of newly made yogurt with some blueberry jam and maple almond granola.
7. Save some of your homemade yogurt to use as a starter for your next batch. Generally this only works for 4-5 batches before having to start again with some store-bought starter. I have heard that you can freeze a part of your yogurt too, to use for a starter as needed.
Update 10/24: Made another batch using the last spoonfuls of my first batch, and incubated for ~6 hours in the oven. This gave the exact “sour” taste I was looking for in yogurt but I noticed that even though I kept my first batch in the refrigerator, it progressively got more sour over the course of a week. I’m wondering how this second batch will behave in a few days…
If you have any suggestions or ideas for homemade yogurt, please give me a shout. 🙂