Update! I rewrote my yogurt tutorial in 2016 with tips and tricks to make your yogurt even thicker. You can find it here.
Did you try the butter or tortilla tutorial I recently posted? If not, maybe this one is more your pace. Yogurt. One of the easiest and most common fermented foods. And the cost is about half that of store-bought yogurt.
This recipe is nearly foolproof yogurt every time. No special equipment needed. Making yogurt is ridiculously easy. We make it three times a week.
Homemade Yogurt Tutorial
1 Quart milk (raw is awesome but store-bought works great, too)
1 Tb yogurt culture (details on lively yogurt cultures are below)
Cooler, oven, heating pad or yogurt maker
Kitchen thermometer (optional)
Step 1: Heat
Warm 1 Qt of milk over medium-low heat until it is about to simmer. A skin will form on the top. Stir it in (my method) or lift it off (Pete's choice). If you are using a thermometer heat to 180 F/82 C.
Why heat? Heating the milk to nearly boiling kills anything living in your milk and gives the yogurt an unpopulated place to grow and thrive.
Remove from heat.
Step 2: Cool
Transfer your still hot (but not jar-breakingly hot) milk to a clean wide mouth quart jar. I do this little by little to ensure I don't crack my jar. Pour, swirl, wait. Pour, swirl, wait. Then pour the rest in.
Allow to cool until it feels warm but not hot to the touch (if you are using a thermometer it will be between 108 F - 110 F (42 - 43 C).) Cool adequately so that you don't kill your culture.
Step 3: Culture
Add 1 Tb of unflavored live yogurt.
How do you source good yogurt? Look local. Do you have a friend who makes yogurt? Ask for a bit. Is there a local or regional brand at your coop or grocery store? Try a small cup. Always choose unflavored yogurt because the sugars in sweetened yogurt weakens the culture and doesn't result in thick yogurt.
Blend the yogurt into a small bowl of milk or add to the jar and shake well (really well) to incorporate. Don't add extra. In yogurt making less is definitely more. I've experimented with different quantities for years, but only after reading Wild Fermentation did I find this perfect quantity. Our yogurt is now amazingly thick thanks to this minimal quantity of culture.
Step 4: Insulate
Place your quart jar in one of three places:
A. A cooler filled half way with very warm water. This method requires a bit of monitoring. Check the water temp a couple of times. Is it still warm? If not carefully scoop some out and replace with hot water.
B. A warm oven. Turn on your pilot light and place jar inside. This is our preferred method. We make yogurt in 1/2 gallon jars this way frequently.
C. A yogurt maker. There are styles with little glass cups that you can find second hand, or newer versions like the one above. I bought this one on Ebay for $8 including shipping. Score. In essence a yogurt maker adds heat and insulates to keep your yogurt warm while it cultures.
D. Heating pad on low heat. This can be tricky if your heating pad gets too hot, but can work beautifully. Place heating pat in the bottom of a cooler and cover with a thick towel. Set to low and place yogurt on top. Cover.
Step 5: Wait
Let your yogurt culture undisturbed for 4 - 12 hours. Four makes for mild, thick yogurt and the full 12 hours creates a more sour yogurt with no residual milk sugars - great for people sensitive to such things. Don't jostle your yogurt while it cultures or it will be thin and disappointing.
Step 6: Chill
Cool your yogurt before you scoop it out or it will separate a bit. My kids love warm yogurt and we use whey for lots of other things, so we sometimes scoop while warm, but if you want your yogurt to not separate pop it in the fridge for an hour.
Step 7: Enjoy!
Fill a bowl with your homemade yogurt, some fresh fruit, granola, or a drizzle of maple syrup. This yogurt is so good that I ate two bowls while writing this. Really.