Ginger beer plant, Volga mushroom and kombucha

I recently came across this article, a really interesting writing on how in the old days people used to use and share something called ginger beer plant (aka "bees"), a weird gelatinous lumpy thing, to make ginger beer. That reminded me of something my mom told me about when I was younger. In the old days in Sweden when she used to live there people could buy at the pharmacy a living flat round disk that you kept in a jar with water and drank the broth of. My memory was bad so I sent her the link to the article saying I wondered if it was the same thing and what her "thing" was called. She replied:

No the thing that I had was called a "Volga mushroom" after the river Volga in Russia. Also, it was not a mushroom but more like a round very firm substance that was thicker in the middle than on the edges and cutting it was like cutting meat although much firmer. The color was white/slightly pink and it grew so you had to divide it now and then because it became the size of a dinner plate. They were sold at the old fashioned pharmacies we had in Sweden when I lived there. You made a black tea solution with sugar in it and let the whole thing stand for five to seven days and then you drank the product and it was considered beneficial to your health.
Love Mama xox

 So I googled "volga mushroom" and discovered that it's basically a SCOBY used to make kombucha. I've made ginger beer before but only with yeast, I'd like to try making this as well as kombucha sometime though.