Sour Wort Rookie Question

[boomslang]

Hey guys, I tried my hand at brewing a sour-wort berlinerweisse yesterday and all seems to be going well.

Very small, 3 litre batch, which I added around 50g of whole grains to and kept at a cosy 43 degrees over night. I'm going to continue heating it to let the bacteria do their job, but I've just checked now and it's giving off all kinds of bubbles?

The demijohn literally looks like it's undergoing fermentation already. Could this be because of natural yeast on the grains, or is this to be expected from souring a wort?

I'm not worried, it was a very very cheap brew, but can anyone shed some light for further notice?

Cheers fellas.

 

[Gnomebrewer]

It's probably too late for you now, but a few thoughts on this....firstly, I'm only just about to brew my first sour, so I'm by no means an expert....

Souring is also a form of fermentation (acid producing rather than alcohol).
There is natural bacteria, and probably yeast, on the grains.
You should check the gravity and pH - ideally (assuming you are souring then adding yeast ethanol production once desired pH is reached) pH should drop in to the low to mid 3's before the gravity starts dropping.

 

[RPh_Guy]

Sounds to me like some wild yeast, but probably also the wild bacteria you were intending to pitch.

Have you smelled or tasted it yet? Don't give up on it unless it smells horrible.

 

[Morrey]

By no means do I want to discourage your au naturale efforts, but the same doubts you are having, I attempt to avoid. When it is so simple and inexpensive to introduce a lab cultured lacto strain for a few cents, why risk time and effort for naught. It is simple to sour wort with Swanson's L Plantarum probiotic tabs with a few of them per batch.