Reasons to Make Your Own Yogurt:
- It is cheaper to buy milk and make your own yogurt than it is to buy yogurt.
- Store-bought yogurt, even plain yogurt, often has additives you can avoid by making it yourself.
- It can be less sour and more sweet tasting than store-bought plain yogurt.
- It’s FUN! (Which is really the best reason of all)
- You’ll be shocked at how easy it is.
How to Make Yogurt:
- Fill a quart sized glass jar (a canning jar works best) with fresh milk.
- Fill a large pot with water and place an old dish rag in the bottom of the water. (This will prevent the jar from jangling against the bottom of the pot when it is heated.) And place it on the stove burner.
- Put the jar of milk inside the pot of water, making sure the water comes at least half way up the side of the jar.
- Place a candy thermometer inside the jar of milk. (These are very cheap and easy to come by. Most grocery stores sell them.)
- Turn the stove burner on to medium-high heat. Keep an eye on it to make sure the water doesn’t boil over at any point.
- Occasionally stir the milk and check its temperature on the thermometer.
- When the milk reaches 180 degrees F, turn off the stove and remove the jar of milk from the pot of boiling water with hot pads. Keep the thermometer in the milk.
- Allow the milk to cool to 120 degrees. While the milk is cooling, get a few tablespoons of plain yogurt out of the fridge and let it warm to room temperature.
- Add 2 to 3 tablespoons (I don’t measure, I just dump), of plain, room temperature, yogurt in to the milk and stir. This yogurt is your “starter culture.” (The yogurt you use can be store-bought, as long as it contains live active cultures, or it can be from the last batch you made. After several generations of using the yogurt from your previous batch to make your next one, it begins to lose its ability to culture well and you’ll have to start with some store-bought yogurt again.)
- Preheat your oven to 120 degrees and then turn it off.
- Remove the thermometer from the milk. Put a lid on the jar of milk. Wrap the jar in a dishtowel and place it in the preheated, but off, oven.
- Set the timer for 6 hours. Do not disturb the yogurt.
- When 6 hours has passed. Remove the jar from the oven and pop it in the fridge! Voila! You have yogurt! Homemade yogurt is usually thinner than store-bought, (because store-bought has extra ingredients added to thicken it further), so don’t be surprised by that.
Yogurt is too thin and runny:
First, it will be thinner than store-bought yogurt, but if it is really too thin, there may be several reasons:
1. You may not have used enough starter culture in step #9.
2. The starter you used didn’t have active cultures in it.
3. The starter yogurt was getting to be too many generations old and you need to start over with a few tablespoons of store-bought yogurt.
4. You didn’t let the milk cool enough before you added the starter in step #9 (more than 120 degrees will kill the culture and it can’t reproduce).
5. You let the milk cool off too much before adding the yogurt in step #9 (90 degrees or less is too cold for the culture to reproduce).
6. Your oven was hotter than 120 degrees when you put the jar of milk and yogurt mixture into it and the mixture got too hot.
Maintaining a temperature range between 90 and 120 degrees F is necessary for the duration of the 6 hours of culture time. If it gets too hot, the yogurt cultures die and if it gets too cold they go dormant and stop reproducing. If incubated at the higher end of the temperature range, the yogurt cultures more quickly, at the lower end it cultures more slowly and may need more than 6 hours. You can add dried milk powder or gelatin to the milk before culturing it for a thicker yogurt.
If the whey (thin, yellow fluid) separated from the rest of the yogurt, it could be because the yogurt was disturbed somehow while it was culturing. The yogurt is still perfectly good to eat, but may be a bit less smooth in texture. You can either stir the whey back in or you can pour it off for a thicker yogurt. If you pour the whey off, you can use it in smoothies, soups, baking, etc. Whey is very high in protein.
Yogurt is very sour:
If the taste of the yogurt is very sour it could be a couple things: first, the longer time it spends culturing, the more sour it will be. You can let it sit longer than 6 hours and it will continue to culture and thicken, but it will become more sour to taste, although it will still be perfectly fine to eat. Second, it could be that your starter culture came from a sour batch of yogurt. I have found that when I use a starter from a batch that was more sour the next batch is more sour also.