I have been reading this post and have so insight on Kefir.
I purchases my milk kefir grains fron Cultures for Health. I hydrated the grains as directed and haven’t had any problems. I live in South Florida where it’s warm. My grains ferment in about 12 hours. They taste the best at this time. Consistancy is thick and sometimes lumpy. Sometimes I refrigerate them and sometimes I let them go for a 2nd fermentation. They will last several weeks in the refrigerator. The longer they set the more tart they will taste and the odor will be stronger also. Find a place that your Kefir is comfortable. Mine happens to be on a piano bench in my frontroom. There is a fan in the area. They do the best there for me. Best of luck,