PNB Rack to secondary
After 9 days in the primary, the PNB fermentation has slowed to < 1 bubble/minute. Almost all bubbling activity on the surface has ceased, so I decided to finish the primary, and rack to the secondary.
There is a distinct layer of yeast on top of the trub layer. Both layers are about 1cm.
I filled my syphon tube and racking cane with sanitizer, by connecting the tube to the tap on the sanitizer bucket. Once the whole thing was full, I stopped flow with a bulldog clip over the folded tubing.
I put the racking cane end of the syphon assembly in the primary, and let the beer displace all the sanitizer into a waste jug. I then filled a test tube for a gravity reading. The measurement was 1025 at 70 deg F, so temperature corrected is 1026, which corresponds to "potential alcohol" of 3.6%. Since the OG was 1044 (6% potential alc.), we have only 2.4% alcohol. AA is 1-(26/44) = 41%. This is not really as far along as I'd hoped, so hopefully we'l lget more attenuation in the secondary.
I'm hoping for an FG in the 1010-1015 range. This will equate to 4-4.6% alc. and 66-77% AA, so I guess we're about 2/3 of the way along.
I tasted it. It has an interesting sweet and sour quality. There is still lots of sugar in here, which I hope can still be fermented, and I guess the sour taste comes from yeast. Probably good that there's still plenty of yeast in suspension. There is enough hoppiness, which I was concerned about, from the 12 year old hopped ME.
I think this one needs at least 2 more weeks before I bottle, maybe more.
Even if this doesn't turn out to be drinkable, it has still been worth making it. I feel a lot happier with my technique, from preparing an boiling wort, to racking and syphoning, to general sanitation.
At this stage, I believe there are 3 factors contributing to the slow/sluggish fermentation.
1. Slow chilling of wort. At first, I just put the pot in the sink with cold water; the pot was only 1/2 submerged, so immediately I had <50% of potential cooling efficiency. Only when I put it in a bucket with ice (fully submerged) did the temperature start to drop off at a useful rate. I'll use the ice-bucket again next time (and make sure I have plenty of ice).
2. Poor aeration. I tried aerating the 2.5 gallons of water first, then the whole wort, by shaking. I must have got some aeration, but could do much better. I've been thinking a lot about this, and when I was cleaning the primary with a bottle brush today, after racking, it struck me that swishing the bottle brush around in liquid produces a lot of bubbles and general frothiness. I figured that a bottle brush connected to a power drill could be just the trick. I used various fittings to connect a bottle brush (not carboy brush) to my power drill, and put ~5 gall. of water in the 6.5 gall. carboy. This system really agitated the water. I couldn't find any literature about this method. I think the only downside is potential sanitation problems. The bottle brush is probably a haven for all sorts of nasties, and I think is galvanised, not stainless steel. If I use this method, I'd like to start with a nice new clean brush. Perhaps I can build some kind of whisk-type thing that'l do the same job.
3. Old malt extract. Nothing I can do about this now for this batch, but will be instantly remedied next time. If I ever come across old malt again, I'll use it in less than 50% proportion with new malt.
So for next time round, I think the biggest hurdle is getting good aeration.
--------------
I went to a party last night and took home a 3L wine bottle that was there. The wine was pretty crap (what can you expect for $9 for 4 regular bottles worth), but the bottle will make a near perfect yeast starter bottle. The neck is even the right size for one of my stopper/airlocks.
There is a distinct layer of yeast on top of the trub layer. Both layers are about 1cm.
I filled my syphon tube and racking cane with sanitizer, by connecting the tube to the tap on the sanitizer bucket. Once the whole thing was full, I stopped flow with a bulldog clip over the folded tubing.
I put the racking cane end of the syphon assembly in the primary, and let the beer displace all the sanitizer into a waste jug. I then filled a test tube for a gravity reading. The measurement was 1025 at 70 deg F, so temperature corrected is 1026, which corresponds to "potential alcohol" of 3.6%. Since the OG was 1044 (6% potential alc.), we have only 2.4% alcohol. AA is 1-(26/44) = 41%. This is not really as far along as I'd hoped, so hopefully we'l lget more attenuation in the secondary.
I'm hoping for an FG in the 1010-1015 range. This will equate to 4-4.6% alc. and 66-77% AA, so I guess we're about 2/3 of the way along.
I tasted it. It has an interesting sweet and sour quality. There is still lots of sugar in here, which I hope can still be fermented, and I guess the sour taste comes from yeast. Probably good that there's still plenty of yeast in suspension. There is enough hoppiness, which I was concerned about, from the 12 year old hopped ME.
I think this one needs at least 2 more weeks before I bottle, maybe more.
Even if this doesn't turn out to be drinkable, it has still been worth making it. I feel a lot happier with my technique, from preparing an boiling wort, to racking and syphoning, to general sanitation.
At this stage, I believe there are 3 factors contributing to the slow/sluggish fermentation.
1. Slow chilling of wort. At first, I just put the pot in the sink with cold water; the pot was only 1/2 submerged, so immediately I had <50% of potential cooling efficiency. Only when I put it in a bucket with ice (fully submerged) did the temperature start to drop off at a useful rate. I'll use the ice-bucket again next time (and make sure I have plenty of ice).
2. Poor aeration. I tried aerating the 2.5 gallons of water first, then the whole wort, by shaking. I must have got some aeration, but could do much better. I've been thinking a lot about this, and when I was cleaning the primary with a bottle brush today, after racking, it struck me that swishing the bottle brush around in liquid produces a lot of bubbles and general frothiness. I figured that a bottle brush connected to a power drill could be just the trick. I used various fittings to connect a bottle brush (not carboy brush) to my power drill, and put ~5 gall. of water in the 6.5 gall. carboy. This system really agitated the water. I couldn't find any literature about this method. I think the only downside is potential sanitation problems. The bottle brush is probably a haven for all sorts of nasties, and I think is galvanised, not stainless steel. If I use this method, I'd like to start with a nice new clean brush. Perhaps I can build some kind of whisk-type thing that'l do the same job.
3. Old malt extract. Nothing I can do about this now for this batch, but will be instantly remedied next time. If I ever come across old malt again, I'll use it in less than 50% proportion with new malt.
So for next time round, I think the biggest hurdle is getting good aeration.
--------------
I went to a party last night and took home a 3L wine bottle that was there. The wine was pretty crap (what can you expect for $9 for 4 regular bottles worth), but the bottle will make a near perfect yeast starter bottle. The neck is even the right size for one of my stopper/airlocks.
posted by number9 at 8:12 PM
1 Comments:
I took another look at the yeast I used. Here is the data sheet: http://consumer.lallemand.com/danstar-lalvin/PDF/Nottingham%20July%202004.pdf
Apparently the expected attenuation is "High" down to 1008 FG. So the yeast itself is not to blame for the slow fermentation. The yeast is well within its expiry date (by 20 months).
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