My old friend from India, Madhu Puri Trehan, told me many years ago that she would never buy yogurt as home-made is so easy and so much better. She added that all one has to do is save a little from the present batch to start the next batch.I've long been intending to try making my own yogurt but somehow never got around to it until inspired by my new bread proofer! I wanted to be sure that it would work so I purchased some freeze-dried yogurt culture from Integral Yoga--a store in the West Village in New York. Yogurt culture is also available on line.
In the space of one afternoon I produced 4 half pint jars of deliciously creamy and flavorful yogurt--ever so much better than anything I have ever tasted that was store-bought. I received some excellent guidance from Michael Taylor, producer of the bread proofer. He also gave me moral support when, after about 3-1/2 hours I could detect no thickening. But sure enough, after about 4 hours I could see it was beginning to 'take.' Michael said he uses commercial yogurt as a starter and to check on the container to make sure it says live culture. He uses 1/4 cup per gallon of milk. (I scaled it down to 1 tablespoon for 1 quart of milk. Now I wish I had made more but it's a simple matter to make a new batch.)
Michael's basic technique is as follows: Pre-heat the proofer to 115˚F/46˚C with four empty quart Mason jars inside to get them warm. (This keeps from cooling down the milk when poured into the jars). After heating the milk to 180˚F/82˚C and cooling to 120˚F/49˚C, remove 1 cup of milk, add 1/4 cup of fresh organic yogurt, then stir it back in. Immediately pour the milk/yogurt starter into the jars. The temperature drops to about 112˚F/44˚C. Put all the jars (covered) back in the proofer at 115˚F/46˚C for an hour, then turn down to 110˚F/43˚C. (As the temperature didn't drop after pouring the mixture into the jars--and was 115˚F/46˚C I used 110˚F/43˚C for the entire time.) The total time once the mixture is in the jars and in the proofer is about 4-1/2 hours but if you want more tang leave it in longer. Michael writes: Incredible! Creamy and luscious with the perfect balance of sweetness and acidity. I entirely agree!
I may stop buying crème fraîche as well now that I have the perfect place to incubate it! All you need is 1 cup of heavy cream and 1 tablespoon of buttermilk. Ultra-pasteurized cream will take as long as 36 hours but plain pasteurized cream at 90˚F/32˚C usually takes 12 to 14 hours. I'm going to try 110˚F/43˚C. No need to heat the cream and buttermilk mixture before placing it in the jar(s).