OK, so not everything can be neatly categorized. When that arises, this is where I’m going to put it.
Let me be clear at the outset - while I cook with it I don’t eat it. Hence, I will leave it to others to comment on flavor. Below is my first attempt, based on both a recipe from Pitre’s Instant Pot® Indian cookbook and other suggestions from a variety of online sources (such as this one).
There are two protocols for fermenting yogurt, dubbed “cold start” and “hot start”. In the cold start method, one starts with ultrapasteurized milk, the kind that will keep for months without spoiling. Since it has already been completely sterilized, there is no need to heat it to a high temperature prior to initiating fermentation. On the other hand, the hot start method is for regular old homogenized milk, which does need an initial sterilization step. So which to use? Both have tradeoffs, to wit:
Cold Start is simpler - just dump and go. However, the cost of the milk per quart is about double that of regular milk.
Hot Start uses cheaper milk, but does require initial heating to 180o F, followed by cooling prior to inoculation. Thus, it takes longer to complete.
1 quart whole milk
1 packet of yogurt starter*
- Add milk to inner pot. Select the yogurt cycle set to high and press start.
- When the pot reads “boil” check the temperature of the milk. It should be ~180o F. The pot should turn off after a few minutes; when it does, remove the lid and let the milk cool to < 110o F.
- Remove the film from the surface of the milk by dragging a fork through it.
- Add 1 tbsp yogurt starter culture or 2 tbsp of a previous batch and mix briefly.
- Set yogurt cycle to Low and press start. Time should auto set to 8 hours, and milk will be held at 110o F. I typically set mine to 9 hours, but that’s personal preference.
- Put glass lid or pressure lid on venting on and let incubate. Yogurt is done when it moves as a solid mass.
- Place in refrigerator over night. For Greek style, place it in a strainer lined with cheesecloth or a coffee filter over a bowl.
- In the morning, whisk it until smooth and place in a storage container. For Greek style, place it in a strainer lined with cheesecloth or a coffee filter over a bowl and let it strain 1-2 hours. Reported refrigerator shelf life is two weeks.
* It is possible to start with commercial yogurt, assuming is says “live culture” or somesuch on the package, but I initiallydecided to buy a dehydrated starter from Amazon. Subsequently I’ve been able to keep this going like sourdough starter, making a new batch every week or so.
- Place 1 quart of ultrapastured milk into the pot.
- Add either dried yogurt started or 2 tbsp. active culture yogurt. Stir briefly.
- Press the Yogurt button and select “Low” and the desired incubation time (again, I find 9 hours to be optimal).
- Follow steps 7 and 8 of the hot start method.
So which method is better? I’ve tried both, and in truth I got the best results with a cold start. Yes, the milk is more expensive per volume, but I found that, when buying milk by the half gallon, I usually ended up throwing away the second quart. So, all in all the cost evens out, thus making the convenience of cold start the determining factor.
The results after being drained through a coffee filter overnight
The separated results - greek yogurt on the left and whey on the right. If a thinner yogurt is desired, some of the whey can be whipped into it prior to use.