In response to a question from a list-member about the water in SCD yoghurt and if it is okay if it is sour,

Elaine writes:
The water is not whey, per se. Whey contains lactose is usually the word used when you separate milk into curds (protein) and whey just like Little Jack Horner. There is no culture involved, just separation which I believe is done by using rennet when making cheese.

The water we get in our lengthy fermentation is actually the "water of hydolysis) which forms when the culture splits lactose which yields two monosaccharides and H2O.
It varies often with temperature variations as well as when you use milk with varying amount of fat. Skim milk would yield the most water as it has more lactose than whole milk and, therefore, there would be more water of hydrolysis when this increased amount of lactose is split. If your yoghurt is sour, it is OK

Originally from the Long Island listserve.

Also from Elaine
The water of hydrolysis contains galactose, some proteins like lactoalbumin and some lactic acid. What you are getting in dripped yogurt is almost pure casein.

From Pecan Bread support group