by nreid on Fri Sep 05, 2014 5:15 pm
@laripu
I don't profess to be a "more experienced" person in any reagrd. But I can confirm that in no way is a Jun culture free of yeast. Yeast is everywhere in our environment and all over us, inside our bodies, and yes, also inside a Jun culture and its "tea". It's a basic fact of biology that yeasts inhabit the same environments we inhabit, just like millions of other fungi and bacteria we're completely oblivious to.
For example, think of how sourdough cultures used in bread making are fermented. These cultures rely in part on wild yeasts in their surrounding enviroments to establish themselves. This is why the flavour of sourdough cultures can very so widely from place to place - even just the wild yeasts within an individual home or region can be a little different than those found in other places. (This is also why buying a sourdough culture from SanFrancisco is pointless - the culture will quickly acclimate to the wild yeasts in your own home enviroment so that it no longer retains the strains of yeasts that make SanFrancisco sourdough breads famous.) So when it comes to a Jun culture, no one can claim it is yeast-free. By virture of the way the culture is fermented via being exposed to air means it has yeast on and in it.
However, according to Hannah Crum of Kombucha Kamp, apparently "Jun cultures and Kombucha SCOBYs look similar but thrive on completely different substrates." Therefore, it is likely that due to the differences in brewing methods and in the ingredients used, the yeast compostion of a Jun culture is different from a kombucha culture. (Although brewing both Jun and kombucha in the same enviroment will result in some similarities in yeast composition.) I don't necessarily think, though, that the use of the term "SCOBY" in regard to a Jun culture is wrong, as a Jun culture is still technically a "Symbiotic Community Of Bacteria and Yeast". One reason is due to the way in which black tea is produced from fresh tea leaves (black tea is fermented) may introduce yeasts into a kombucha scoby that aren't present in a green tea. The use of honey in Jun also introduces yeasts into a Jun brew that are not necessarily present in a kombucha brew. Also, keep in mind that the production methods used to process black and green teas could vary from producer to producer depending on the quality of their practices in regard to sanitation and the storage of fresh and dried tea leaves. This too also introduces various yeasts into Jun and kombucha teas that can vary depending on the type of tea used in brews.
It's worth noting that a kombucha scoby cannot be "converted" to a Jun culture by virtue of the fact that they are just not the same colonies of organisims. As Hanna Crum points out, Jun substrates evolved differently than kombucha scobies. This is due to the difference in basic nature of the materials that comprise a Jun culture. So if you want a true Jun culture, get one. Converting a kombucha scoby into a Jun culture will only end up in something other than a Jun culture.