Heat milk to 86*, or start with warm fresh, just milked, milk. Sprinkle culture over milk and let rehydrate 1 minute, stir in. Cover and let ripen for 1 hour.
Add annatto, mix in. Add rennet, mix in. (I don’t dilute annatto or rennet). Cover and let sit 40 minutes or until you get a clean break.
Cut curd into 1/2” pieces and let sit for 5 minutes.
Then slowly bring the curds to 104* over about 45 minutes. Stir continuously, but slowly. Once curds reach 104, remove from heat and rest curds undisturbed for 15 minutes.
Ladle enough whey out until you see curds. Replace the whey with the same amount of 104* water. Gently stir for 2 minutes.
Rest for 10 minutes.
Strain curds. Transfer curds to a lined cheese mold.
Press 5 lbs for 1 hr. Remove cheese, flip, and press again at 10lbs for 12 hrs.
Brine cheese in a medium-heavy brine for 8 hrs.
Remove cheese from brine, pat dry, and air-dry at room temp until surface is dry to the touch.
Vac seal and age in cheese cave for 6 weeks. You can age longer, but the Colby will get sharp.