I'm looking to increase my quantity of GBP to share with a friend. I've brewed a few batches of ginger beer, but I always end up with the same amount or slightly less GBP than I started with. What needs to be done to come out with more GBP after a batch, or how can I just increase my quantity of GBP? Leave it in a jar full of sugar and ginger for n days?
This is an universal solution that works for most microorganisms, and I bet it will for yours, too. After all, both Saccharomyces and Lactobacillus finds everything they need in it, so symbiotic colony of them should as well.
Use beer wort, may be from extract. It's a soup of everything microorganisms needs. OG at about 8 to 10 Plato (1.030 to 1.040 as Americans call it). Put it in a jar. Add yeast nutrient, compound one. Yeast cell walls kind, if possible. Aerate it by swirling. Try on small part of your GBP, and see yourself. Magnetic stirrer would be ideal, but if you don't have, swirl it three, four times a day, at least few minutes each. This is to remove CO2 and add oxygen.