Greek Gods: "Kefi" Isn't Related to "Kefir"

the offending kefir bottle
Greek Gods, one of my favorite brands for kefir, has a little story on the back of their bottles:
The Greek word "kefi" refers to enthusiasm and the positive joyful spirit of life. Believed to have been consumed for thousands of years, kefir remains a great addition to any diet. It is delicious and may be beneficial to the body. The Greek Gods kefir is exceptionally creamy, smooth and rich in taste.
The only problem—which you might suspect right away—is this:

The word "kefi" has nothing to do with the word "kefir."

The word "kefir" is of unsure origins, but it is known to have come from the north Caucasus region from a complex family of languages entirely unrelated to Greek. The word might have something to do with "foam" (which makes sense)—but nothing to do with joy.

The funniest part, I think, is that Greek Gods is doing exactly the same thing the father did in My Big Fat Greek Wedding—taking any word and creating a false etymology going back to Greek.

Nice try, kefir company, but I caught you!