I mashed a Berliner Weisse on Tuesday for kettle souring - pasteurised it at 82°C for a bit then chilled it and dropped it into an old fermenter so it would fit in my temperature controlled brew fridge at 35°C to incubate.
I used a carton of Fage Total 0% for the lactobacillus source, which I've done before with good success. I didn't pre-acidify the wort (as I hadn't bothered doing so last time) so the starting pH was 5.6, S.G. 10.43.
Checked 24h in - pH was 4.82. So far so good.
After 48h, the pH was 4.2. Was hoping it would be down to the target of 3.5 by now but figured I'd leave it to run
60h and it was at 3.98, with significant bubbling in the airlock (should have realised this was a sign of things to come)
72h in (Friday night) and it had reached 3.72. Okay, tomorrow is the day for finishing this off.
Woke up this morning, 84h in and the pH had risen to 4.2. Checked the gravity and it had dropped to 1.018...
I'm guessing either the lacto (or a wild/residual yeast in the fermenter) has turned some of the sugars into alcohol instead of lactic acid, which I guess might account for the rise in pH.
Tasted fine, so I brought it back to the boil, added some lactose (going to fruit it with raspberries, and maybe a touch of vanilla in secondary) and threw in half a pack of CML Kveik. Hopefully the brief boil didn't drive off too much of the alcohol, as there's not much sugar left to ferment out now by the look of it.
It's back in the brew fridge, so I guess I'll find out what the end result is in a couple of days. No idea what the ABV is going to be - so long as it tastes okay I'm not going to worry too much tbh, but this one has me scratching my head trying to work out what went wrong. If anyone has any thoughts or opinions they'd be gratefully received.
I used a carton of Fage Total 0% for the lactobacillus source, which I've done before with good success. I didn't pre-acidify the wort (as I hadn't bothered doing so last time) so the starting pH was 5.6, S.G. 10.43.
Checked 24h in - pH was 4.82. So far so good.
After 48h, the pH was 4.2. Was hoping it would be down to the target of 3.5 by now but figured I'd leave it to run
60h and it was at 3.98, with significant bubbling in the airlock (should have realised this was a sign of things to come)
72h in (Friday night) and it had reached 3.72. Okay, tomorrow is the day for finishing this off.
Woke up this morning, 84h in and the pH had risen to 4.2. Checked the gravity and it had dropped to 1.018...
I'm guessing either the lacto (or a wild/residual yeast in the fermenter) has turned some of the sugars into alcohol instead of lactic acid, which I guess might account for the rise in pH.
Tasted fine, so I brought it back to the boil, added some lactose (going to fruit it with raspberries, and maybe a touch of vanilla in secondary) and threw in half a pack of CML Kveik. Hopefully the brief boil didn't drive off too much of the alcohol, as there's not much sugar left to ferment out now by the look of it.
It's back in the brew fridge, so I guess I'll find out what the end result is in a couple of days. No idea what the ABV is going to be - so long as it tastes okay I'm not going to worry too much tbh, but this one has me scratching my head trying to work out what went wrong. If anyone has any thoughts or opinions they'd be gratefully received.
