3. Incubate.
Pour immediately into clean, sterilized, warm
container(s); cover and place in prepared
incubator. Close the incubator and incubate
for 4–7 hours at 110°F (plus or minus 5°F.)
Yogurt should set firm when the proper acid
level is achieved (pH 4.6). Incubating yogurt
for several hours after the yogurt has set will
produce more acidity. This will result in a
more tart or acidic flavor and eventually cause
the whey to separate.