Homemade Yogurt

Homemade yogurt. Here's why: 

I like tangy plain yogurt of the variety sold at my local co-op. 

I can't possibly re-use all of of the plastic yogurt containers that are piling up in my cupboard.

The containers aren't recyclable. Guilt, guilt, guilt.

Yogurt in bulk. What could be better?

I've made 3 or 4 batches of this with varying results. The most important secrets seem to be the use of milk solids and incubation time. Thanks to the assistance of not one but two yogurt gurus, I have a darn good recipe.

1 quart milk

1 packet starter culture (or 1 Tbsp live active culture yogurt)

1/2 c. non-fat dried milk powder

Heat milk in a double boiler (don't let it boil). When it reaches 100 degrees scoop out 1/2 c. and put it in a separate bowl with the starter culture. Set aside. Note that temps above 120 degrees will kill the culturing bacteria.

Add powdered milk to warm milk and continue heating until it reaches 180 degrees. Hold temp at 180 degrees for about 20 mins and then quickly bring the temp down to 116 degrees. In the winter this can be done by placing the milk pan in the snow, or just use a sink full of ice water. The temp will drop surprisingly quickly so watch it.

Add the 116-degree milk to the starter culture until you have about 1 1/2 c. Then add the starter to the milk. This split process might give the culture a chance to acclimate to the new temp.

Put the milk into a sealed container. Ideally you'll culture it at a constant 100-110 degrees. Without a yogurt incubator, you can warm your oven and leave the oven light on. You can put it in a cooler and wrap a big blanket around it. I tried monitoring a crock pot, intermittently turning the heat on and off. Skip this - unless you have nothing better to do that watch yogurt incubate for 7 hours. 

I put the milk in a jar and into a styrofoam cooler. Ideal incubation time is 7 1/2 hours. 5 hours will make it sweet but not solid. At 9 hours it starts to get a little sour. This still might taste good with middle eastern dishes, for example. I tried Doogh, a savory Persian yogurt drink, for the first time last weekend and immediately thought of homemade yogurt.

After incubation, put to yogurt in the fridge right away and chill for a day. The yogurt will firm up more as it cools. My yogurt has tended toward a thinner consistency, likely because I incubate below 100 degrees. But it's tasty and is great in smoothies. 

* Recipe thanks to Jamin Johnson's decades-long yogurt experimentation. Additional tips from Lauren Dee.