I put on a Stout a few (3?) weeks go with US05 yeast.
Activity was slow to start, but took off with a light krausen which subsided after a week.
Still sitting on the yeast in Primary, I noticed activity again about 3 days ago.
The new activity has produced a very thin Krausen with airlock activity.
Infection? I don't think so, I have been meticulous.
I have found a number of reasons why this might be happening...
Change in air pressure.
Solution releasing CO2.
Change in Temperature.
Yeast has reacted to change in Temp and has found sugars to work on.
I may have underpitched initially as the yeast was from trub, and I could not for the life of me see the separation beween Yeast and trub when washing.
Has anone else had fermentation taking off again?
I will take a Gravity reading, sample, smell and taste this evening.
Have you a photo of the new krausen?
What was the OG?
I had a high gravity stout that stopped and started again a few days later. It tasted fine. I think high gravity beers can do funny things. It was irish ale yeast though
Infection is the first thing I though of as well. Lets hope not but keep us posted as regards its journey. :(
Temperature has taken an upwards swing recently, I call temps.
Sent using a complex system of semaphore and ninjas.
Temp is my first guess.
As temperature increases, the amount of dissolved carbon dioxide that the beer can support decreases, so CO2 would come out of solution and bubble to the surface. This will look like krausen, and act like krausen
You might find it happens if you lager in demijohns in the fridge. As it warms back up it will release the carbon dioxide that is stored there. It can only go back into solution if the beer gets cooled down and the CO2 couldn't leave the vessel.
I need to check my recipe for the OG, but It smells perfect and tastes good.
I can just about see yeast activity, so I'm thinking they've woken up for seconds!
I need to get a wee bit of carb into it and serve it through a handpump.
OG 1050
Gravity is currently 1012
BeerSmith 2 Recipe Printout - http://www.beersmith.com
Recipe: The Dark #27
Brewer: John Mangan
Asst Brewer:
Style: Dry Stout
TYPE: All Grain
Taste: (30.0)
Recipe Specifications
--------------------------
Boil Size: 28.04 l
Post Boil Volume: 26.00 l
Batch Size (fermenter): 23.00 l
Bottling Volume: 21.49 l
Estimated OG: 1.047 SG
Estimated Color: 66.9 EBC
Estimated IBU: 39.1 IBUs
Brewhouse Efficiency: 75.00 %
Est Mash Efficiency: 81.5 %
Boil Time: 60 Minutes
Ingredients:
------------
Amt Name Type # %/IBU
2.050 kg Pale Malt (2 Row) UK (5.9 EBC) Grain 1 40.7 %
0.900 kg Stout Malt (5.9 EBC) Grain 2 17.9 %
0.450 kg Roasted Barley (591.0 EBC) Grain 3 8.9 %
0.301 kg Barley, Flaked (3.3 EBC) Grain 4 6.0 %
0.300 kg Brown Malt (430.0 EBC) Grain 5 6.0 %
0.284 kg Caramunich Malt (110.3 EBC) Grain 6 5.6 %
0.257 kg Golden Naked Oats (11.0 EBC) Grain 7 5.1 %
0.250 kg Aromatic Malt (60.0 EBC) Grain 8 5.0 %
0.147 kg Wheat, Torrified (3.3 EBC) Grain 9 2.9 %
0.100 kg Black Barley (Stout) (985.0 EBC) Grain 10 2.0 %
20.00 g Bramling Cross [6.00 %] - First Wort 60. Hop 11 13.1 IBUs
40.00 g Bramling Cross [6.00 %] - Boil 60.0 min Hop 12 23.8 IBUs
0.30 tsp Irish Moss (Boil 10.0 mins) Fining 13 -
10.00 g Bramling Cross [6.00 %] - Boil 10.0 min Hop 14 2.2 IBUs
1.0 pkg Safale American (DCL/Fermentis #US-05) Yeast 15 -
Mash Schedule: Single Infusion, Full Body
Total Grain Weight: 5.039 kg
----------------------------
Name Description Step Temperat Step Time
Mash In Add 14.34 l of water at 76.3 C 68.9 C 45 min
Mash Out Add 5.26 l of water at 96.8 C 75.6 C 10 min
Sparge: Fly sparge with 14.69 l water at 75.6 C
Notes:
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