Never Rinse Them in Water
The coating of milk around the kefir grains protects them and makes them strong. Think of it this way. It is like walking around naked in a snowstorm. They need this coating to reproduce themselves, and protect themselves, because of the combination of bacteria and yeast they make up the composition of kefir grains. Rinsing them washes this away.
If you need to change milks then rinse them in the milk you are changing them too. You really don’t need to rinse them at all, but if you want to rinse them. Rinse them in fresh milk. You can also give them a prebiotic like Prebio Plus which feeds them and makes them stronger and will also make your kefir more creamy especially if it is separating a lot.
Keep Your Kefir Grains Alive
Resist the temptation to rinse them and tell your friends Donna said so. I will sleep so much better at night if you do. Tortures me when people tell me they’ve rinsed their kefir grains.