Making my own Saudi Arabian Buttermilk ( Kefir )

If anyone knows of a better forum category please advise or move this message please.    For two years I have been purchasing one quart Lifeway brand KEFIR ($4) at Kroger grocery store and mixing with one gallon of skim milk ($3) that has been heated to 75 degrees F in the microwave.  This mix is left out on kitchen counter room temp for 2 days.   Lots lf kurds form from the live cultures in the form of general thickening of the liquid.   I then blend in a blender 16 oz of frozen blueberries and pour this into the two empty gallon jugs that I have poured the mixture in and shake vigorously.  This is then refrigerated and it takes about ten to fourteen days to consume usually.  In anycase I am doing this for my 95 yr old mom and she drinks at least 24 oz daily.  Into this blender mix I sometimes add olive oil ( cant taste it ) carrots or carrot juice or some powdered fiber like metamucile etc.
Significant improvements in pooping, eye health, and calcium absorbstion etc.   It tasted really good like fruit flavored yogurt etc.   I just thought I would share this as I have made yogurt before and the significate difference
is the temperature of  fluid as a different set of bacteria is growing at the much lower temp compared to yogurt which grows at 115 degrees  F.     I believe I have read histories where the camel and goat herders in the middle east preserved their milk in the desert this way a thousand years ago.   Sure enough a bottle of store bought Kefir  was accidentally left in the garage for five months  and had not gone rancid at normal garage temps.    It was quite a bit more acidic than normal Kefir.   I then refrigerated it and then finally drank it all.

It does sound like you're making your own kefir Scott! Have you tried using some of the fermented milk to make another batch, or do you always use a new shop kefir as starter?