I have used half & half, and it usually was very tasty. I got it down to where I could produce 16 ounces a day, so I'd refrigerate the new batch, drink the day-old batch from the fridge, and start a new one all within a few minutes. I decided to cut back when I realized I was consuming more carbs from the milk than I wanted. Homemade kefir is much easier than yogurt and has more varied and healthy cultures than yogurt. For those that want an excellent quality probiotic, it's a winner. Store bought varieties don't come close.