Lifetime Kefir milk kefir grains are one of most high quality grains you will find in the US at this time. Our grains are quality controlled to ensure a high quality product that is unmatched within the kefir community. We use a special process which was developed through many trials and experiments to make sure that our grains are the best you can find. Our commitment to helping others extends beyond our products with our excellent customer service. If you are not happy with any product, we offer a money back or replacement of the product (sometimes both) because we care about our customers. May you have a lifetime of good health!