Hey guys, here’s one for the Single Malt distiller’s here.
I’m having trouble fermenting out my AG Single malt washes. To date, I’ve done 3 and they all have done exactly the same thing.
So, I’m using
4kg of Joe White Traditional Ale malt,
2kg of Simpson medium Peat
5g yeast nutrient
10g gypsum
2 Tbs of Safspirt Grain yeast
My water is soft with minimal mineral content
I mash for 90 mins at 64°, sparge and have 24ish liters at 1.060SG
Pitch the yeast and fermentation kicks off in roughly 6 hrs. Fermentation continues happily at 20-25° for 3-4 days, and then slows to a stop. FG has stalled at 1.020, and I haven’t been able to get them to go any lower.
I’ve tried pitching more yeast, raising the temp to high 20’s, and still no success.
I checked the ph, and they all come in around 3.3-3.4, and the have a strong sweet/sour smell and taste. I tried adding some calcium carbonate, but that didn’t help either.
So I believe that my ph is crashing during the fermentation, and killing off my yeast. But I have not been able to find any info on how to stop it, despite exhaustive searching. I’ve never had this problem with 30+ beers that I’ve brewed, but all 3 single malts have done the same thing.
Any ideas or suggestions on how to prevent this from happening on future attempts?