Self carbing query

Hey there. I am new to this home brew stuff, but picking up things pretty fast through my own experiments. I have started a fiery spiced ginger beer recipe, it kicks ass so far.

My query is about the must. I bottled some spare up to later back sweeten and bring back some of the residual flavours if needed. Well i left it at room temperature and a day later i checked it and there was no carbonation and everything smelled (and tasted) fine. A couple days later though i thought i would use it after the fermentation was transferred to secondary. The surprise was that is had carbed itself, quite a lot considering there wasn't any yeast in the reserved must. Is this supposed to happen? I have heard of the ginger bug, however i assumed that only worked with fresh ginger that hadn't been boiled up. Quite interesting either way, i'd like to try an experiment with this.

After boiling ip you would have let it cool before bottling. If it was uncovered at any time while cooling or even combined with air during transfer from boiling pot to bottle it could easily have picked up some wild yeast in he air. This is why wine makers use Campden tablets and potassium sorbate to stabilise wine. If you ever look into sour dough bread you will see the first step to making a starter is mixing water and flour then wandering around your kitchen whisking the mixture frantically in order to trap theses wild yeast.

Thanks for the heads up! I never thought about yeast being in the air. I might try a soda recipe using wild yeast.

Sure but it's worth keeping in mind that wild yeast will take a lot longer to carb up and also as they are weaker than those strains that you buy, it's easy to stress them which will result in off flavours.