Making yogurt at home is a fairly straight-forward process. Heat milk to 180F (82C), cool that milk to at least 110F (43C), add live cultures, usually in the form of yogurt with said cultures, incubate, then chill.
There are several variables in the process, some of which are: The fat content of the milk (I typically use whole), how long to hold the milk during the initial heat step, how long it takes to cool the milk, the temperature of the incubation step, and the length of time for incubation, to name a few.
While length of time for incubation, and temperature at this stage, clearly contribute to sourness, I am trying to nail down the variable that contributes to a creamy texture. I'm not referring to breaking or clumping, as described in Why isn't my homemade yogurt smooth?. My yogurt comes out smooth.
My initial hypothesis is that holding the milk for a length of time at the initial 180F(82C) (rather than immediately removing from heat and/or chilling) has an impact on final texture. Any thoughts or experience that might inform my hypothesis?
Best Answer
I've been experimenting with goat milk yogurt - changing things up one variable at at time. I've been able to get a consistently creamy texture with 10 minutes at 195, one hour at 120, and then lowering to 86 and incubating until it reaches a pH of around 4.3. A lower pH or a higher incubation temperature result in a more tart (of course) but also more firmly set yogurt. At 4.3 I get something silky smooth.