I've got a blueberry one ready today! I can't wait to try it.
I took a cup of blueberries and whizzed them in a blender. Then I put them in a mason jar with a tablespoon whey, a little bit of sea salt and enough water to fill the jar to 3.5 cups. I like leaving a little head space because when I open the jar, the soda will expand!
I leave it out for about 3 days. I know it's ready once the pop lid is stuck up (unlike sealed down as it would for jelly/jam) and I can't push it down again.
I've done this with all kinds of berries and concord grapes.
My next experiment will be plums I think.
I used curdled milk whey and it definitely was gross! What did I do wrong? I used fresh orange juice and a few tbs. of whey... when I opened it and tasted it, it just tasted like orange juice gone bad and I had to throw it out . How is it supposed to taste? Thanks! I have LOTS of whey and would love to make some YUMMY sodas!
I think NT has a simple recipe for grape juice soda using whey, hold on...
juice 16lb grapes
add 1tbs salt & 1/2 c. whey
ferment three days at room temp, skim off any scum
strain and store in airtight containers in fridge, flavor develops over time
can dilute with water to drink
that said, I like fruity 'whatever-ade' made by adding fruit to the second ferment of my kombucha - it really pulls a lot of the fruit flavor out into the liquid and is strongly fruity even diluted as I usually drink it. I hear the key to bubbles is airtight bottles for the second ferment, so I am sure you could get the soda effect with that too. I haven't had an opportunity to get any airtight bottles but I am looking forward to trying it.