So I'm throwing this one out to the boards to see if I can get any helpful feedback. This one really has me baffled and is threatening to be the first dump-out batch I have brewed in 6 years. I brewed a porter on 9/22 with a target OG of 1.060. I will include the recipe in a separate post but I don't think it is anything out of the ordinary. I am only about 3 brews into my new, larger, igloo-cooler-style mash tun so there were a couple of irregularities in the mash:
1) I am still getting a feel for the thermal response of the system. As a result, my mash started a little warm, about 156F versus my target of 152F
2) Also still getting a feel for average efficiency of this system, so I ended up a bit high on my OG. The value I read was 1.066
I pitched S-04 at 72F and my house ranged from 65-72F over the course of the fermentation There was vigorous fermentation in the first day and it slowed to a very slow bubble by day 6. Let it ferment in the primary for a total of 12 days before transferring it at 1.018 or so to the secondary. It spent 21 days in the secondary and I racked it to a keg at 1.016. At that time, the taste was still a tiny bit sweet and the beer tasted a bit unbalanced, as though I had over hopped it or the malt character hand't come through, but the SG hadn't changed in days and the gravity wasn't obscenely high so I kegged it anyway. It wasn't a great beer, but it wasn't bad at all and sometimes it's hard to tell when the beer is uncarbonated and at room temperature how it will turn out. Now, there were a few unusual things in the kegging process:
1) My kegerator had been empty for about a month and was turned off. I plugged it in a few days before kegging to make sure it was cool and ready. I set the thermostat to its usual position which normally gives me a temp of between 38-40F. I crash cooled the keg and force carbonated at 8 psig. After tasting the beer it was not bad. A bit unbalanced and not quite fully carbonated yet, but decent in a way that makes a man hopeful about what improvements the next couple of days in the keg will bring.
2)Trouble! Two days later I checked on the beer and noticed that a) the temp in the fridge was around 34F and b) the regulator was reading over 10 psig. I suspect that the temperature change was due to the fact that the fridge defrosted while it was unplugged and thereby became a bit more efficient at cooling. The only thing I can think of with the regulator is that I set it to 8 psig when the regulator was at room temperature, and the innards contracted once they cooled, decreasing the restriction and raising pressure.
I poured a glass and, needless to say, it was badly overcarbonated. I got mostly foam and mentally prepared myself for a week long process of venting and letting the keg re-pressurize, then venting some more. Once the foam died down, I tasted the beer again. Wow! It is bad. Specifically, it feels thick on the tongue like an imperial stout or even a barleywine, a complete 180 from the slightly thin mouthfeel of just days before. Second, there is very strong, raisiny taste at the front that was just barely present a couple of days ago. I had originally attributed this to the Special B malt. Finally, there is a "hot" finish that reminds me of a 12%abv beer or even a distilled spirit- again, not at all present 2 days ago. There may even be a bit of phenolic flavor, but there is too much going on with it for me to be sure.
So what happened to that middling beer I put into the keg? Thoughts?
Here is the recipe:
10.75 # 2 row
1 # Munich
.5 # crystal 60
.5 # Special B
.5# Chocolate
.25# Black Patent
1.15 oz Centennial 60 min
.5 oz Goldings 15 min
.5 oz Goldings 1 min
1.5 oz Goldings in secondary
Safale S-04 Dry Ale Yeast
Kevin Schwartzenberg
My first redflag is the yeast...Although I never used it (I have some for an upcoming beer though, but not sure I will use it now), I just came across a thread on Fermentis S-04 on HBT and no one had anything nice to say about it. Alot of off flavors produced... based on your OG and FG sounds like you have almost a 7% ABV beer...so there will be some warmth at the finish...if it is really pronounced fusel alcohol then it can be attributed to a warm ferment. Although 72F is not too bad...Ales should be at 68F...and yes a couple degrees can make a difference. The first three days of fermentation is critical (temp control) as that is when most of the flavors are developed.
As for the over carb, I would think 10 psi should not be too much of an issue...easily solved with a longer tap line...An easy way to drop your carb level is to hook up your CO2 to the outlet side of your keg and reapeatdly lift the pressure relief valve a couple seconds at a time(try around a dozen times)...foam will start to come out of relief valve...what is happening is the CO2 bubbles rise up through the beer and cause CO2 to be scrubbed out of solution....As you may know when you pull off the tap and get a glass full of foam the resulting beer after the foam settles will be flat and dull...
Also...not sure your timeline but looks like your beer is about 6 weeks old? Give it some time to mello out..it is still young beer...Put the keg out on the porch where it is now cold...and let it sit another month or so...I bet it will improve...
Hope this helps...
Thanks for the input. I was a bit concerned about the yeast because I was originally planning to use Wyeast London Ale yeast and couldn't find any. I agree that my ferm temp was high also. What really throws me off is the fact that these flavors seemed to develop only after the beer had been in the keg for a few days. In my limited experience with fusels they tend to be more noticeable when the beer is warm because you get so much more of them in the aroma.
I'm going to have to remember that CO2 scrubbing technique for dealing with overcarbed beers.
For some reason, Porters have been my white whale and haven't been able to pull off a really solid one despite several attempts. I think on my next attempt this weekend I am going to bring things back to basics. Simpler grain bill, skip the dry hopping, and start with S-05. My ferm temp should be perfect now that it has cooled off.
Kevin Schwartzenberg
You can't go wrong with S-05...I would try to ferment at 64F to 66F....that should eliminate any off flavors...I am currently doing a cream ale with S-05 and fermenting at 66F...
One more thought is you might of under-pitched....typically yeast packs are made for 1.050 beers...and even though dry yeast typically has a higher yeast count then liquid yeast, Fermentis is good for two years past date on package...I just bought some and my S-04 was made back in March...and S-05 back in April...based on that date BeerSmith said I should pitch two packs...and that was for a 1.043 OG beer....
I have over-carbed a beer or two before... All I did to lower it was disconnect the keg from the CO2 and beer line, shake it a few times, then purge the CO2 valve. You may have to do this 2-3 times depending on how over-carbed it is. Afterwards reconnect the CO2 at a lower level.
I used the S-04 once and didn't get any off flavors from it. I did ferment at a lower temp than you did though (~66-67). Also prefer S-05.
I have no idea what your problem could be based on your description. Bring some in next meeting. There is nothing in the process that you described that I would think could cause a dramatic change of flavors.
I use Safale 04 all the time, no problems. However, I have not done a side by side with a number of other English yeasts so I am not sure how its flavor profile relates to the other available strains. That would be a great education session if someone wants to put it together.
Ive used s-04 mant times. it is a good english yeast. Should be fermented on cooler side to prevent throwing esters.
Maybe your keg or lines were dirty? and you caught an infection? Hard to imagine at such a low temp....but it is possible.