For me it's a fun hobby. With that said, as a software developer making $XXX,XXX per year, your time is worth more than the money you save by DIY. So it's up to

For me it's a fun hobby. With that said, as a software developer making $XXX,XXX per year, your time is worth more than the money you save by DIY. So it's up to you. The final caveat is that w/ milk kefir in particular, the stuff you buy in the store is different that making it yourself. Commercially made milk kefir is inoculated w/ ~7 specific bacteria strains whereas homemade kefir is made with kefir "grains" --- a symbiotic culture of 40+ different strains. Interesting scientists have not been able to directly synthesize kefir grains in a lab due to how complex the symbiotic ecosystem is. All Kefir grains around the world today are from other grains stretching back thousands of years to when the first grains were discovered (people suspect in the digestive track of a ruminant).