Buttermilk Eurasia Crème frche Europe Sour cream Europe Ropy milks Scandinavia Koumiss Central Asia Kefir Central Asia Product Microbes Lactobacillus, delbrueckii, Streptococcus salivarius (in rural Yogurt areas, assorted lactococci and lactobacilli) Lactococcus lactis, Leuconostoc Buttermilk mesenteroides Crème Lactococcus lactis, Leuconostoc frche mesenteroides Sour Lactococcus lactis, Leuconostoc cream mesenteroides Lactococcus lactis, Leuconostoc Ropy milks mesenteroides (Geotrichum mold) Koumiss Lactobacilli, yeasts Lactococci, Lactobacilli, Acetobacter, Kefir yeasts Product Fermentation Temperature, Time 106–114ºF/41–45ºC, 2–5 hrs, or Yogurt 86ºF/30ºC, 6–12 hrs Buttermilk 72ºF/22ºC, 14–16 hrs Crème frche 68ºF/20ºC, 15–20 hrs Sour cream 72ºF/22ºC, 16 hrs Ropy milks 68ºF/20ºC, 18 hrs Koumiss 80ºF/27ºC, 2–5 hrs plus cool aging Kefir 68ºF/20ºC, 24 hrs Product Acidity Yogurt 1–4% Buttermilk 0.8–1.1% ...milks mesenteroides (Geotrichum mold) Koumiss Lactobacilli, yeasts Lactococci, Lactobacilli, Acetobacter, Kefir yeasts Product Fermentation Temperature, Time 106–114ºF/41–45ºC, 2–5 hrs, or