milk kefir grains fresh mr & mrs. kefir mr & mrs kefir / mmk the healthiest & most active real kefir grains on the market. very well cared for and will make amazing milk kefir for many years to come, grains can last a lifetime. they are sold by mr. & mrs. kefir and shipped fresh. 100% satisfaction guarantee, please contact with any questions or issues. detailed instructions are included and live customer support through mr & mrs kefir website. 24/7 customer support through phone or e-mail. 24 hours and 7 days a week. stir strain & sip!