Low final OG at 1.083 due to low BH & Mash Efficiency so corrected with DME to 1.099 (with hindsight, I probably should have used X amount of sugar too to keep FG estimate a little lower!?)
New FG estimate with DME addition: 1.030
Fermenting the Wee Heavy
6 weeks at constant 18c - Racked to bottling bucket before checking FG (I know!!). I guess fermentation stuck due to yeast flocculation (Wyeast 1728) and needed to be roused. Damn! FG when bottled: 1.038. Thought I’d give it a chance.
Primed with Corn Sugar to 2.30 volumes of CO2.
Checked after 2 weeks conditioning (as after some research was very worried I may have little bottle bombs in the room!) - Carbonation good but far too sweet!
BIG QUESTION (drum roll) - Should I re-pitch and re-ferment?
The first question is how did you measure FG? Did you use a hydrometer or a refractometer? If you used a refractometer you need to calculate a correction for the presence of alcohol which throws off the measurement.
Frankenbrew may have a point, but in this case it’s not the most likely problem. Personally I think 1.099 was maybe too huge for the style. Too much for my own taste anyway.
What temperature are you conditioning the bottles? Fermentation should continue in the bottles, which should trade some of the sweetness for carbonation. I would keep them warm, 70-75 F (21-24 C), and check a bottle for possible overcarbonation every 3 or 4 days. When they begin to overcarbonate, I would bleed some pressure off each bottle then re-cap. You may find they lose enough sweetness this way on their own without having to dump them all into a fermenter for re-fermentation. Might be worth a try. That, or just blend with a little water or light beer in each glass so that the sweetness is not overly strong.
If they aren’t over carbonated after two weeks in the bottle, that’s a pretty solid indication that the fermentation was finished. In which case adding more yeast wouldn’t do anything.
Cheers Dave. I was following Jamil’s BCS recipe. Should be 9.70% ABV, mine turned out 8.10% @ 1.038 and way too syrupy. Conditioning in the living room at about 20-21c. I will try your suggestion of bleeding pressure… How long would you try this method before re-fermentation route?
I was thinking the same… Wondering if there were just to many Dextrins in there from mashing at 68c and then the addition of DME to adjust OG to 1.099? But if this were the case the new estimated FG of 1.030 should still have been achievable but with less ABV and more body yes? Maybe back to yeast flocculation??? Or do you think there would have been enough re-suspended and transferred when racking?
I did end up with 1 litre more wort in the fermenter (need to adjust Loss to Trub & Chiller for next batch), but after entering session figures into Beersmith the estimated OG for new batch size was spot on at 1.083 @ 56.60% BH Efficiency & 67.60% Mash Efficiency. So I believe conversion was complete (need to get some Iodine for mash test too!).
My method will truly only work if fermentation is still happening in the bottles as evidenced by over-carbonation. But if fermentation is totally complete and you’re not experiencing gushers at all, then you may be forced to re-ferment by pouring out all the bottles, adding a metric ton of highly active yeast (sometimes called “krausening”), OR simply dilute the beer enough with water or weak beer so it doesn’t taste overly sweet anymore. Perhaps the very last suggestion is really the best and easiest one to do for this batch. Next time you brew this recipe, don’t add so much sugar.
Now I’m also wondering whether the yeast simply has hit its maximum alcohol tolerance. If that’s the case, a more alcohol tolerant yeast strain would be needed. I’m not very familiar with this yeast strain.
Definitely not the max alcohol tolerance. I use that strain frequently for my Strong Scotch Ales. I’ve taken it up to O.G.'s above 1.100 and abv of @11% with no problem.
The one time I hit 1.038 FG it was because I accidentally mashed in at 164F. In the end there was nothing I could do about it but put the stuff down the drain. And that was my one total failure as a brewer.
My friend, who is also an MD, says that a 1.038 FG brew will give you the shi*s if you drink it. But I didn’t test that because the crap was too sweet to drink.
Mash In temp was 73c (Beersmith) for a 60 min rest at 68c. Hit 68c pretty quickly.
Ph good at 5.43 after 10 min.
Will triple check actual mash temp next time with Thermapen rather than relying on Grainfather temp display. :
Will get some Iodine for mash conversion testing - Maybe need to lower mash temp a couple degrees? Longer rest?
Will check carbonation levels again tonight, see where they’re at.
Would like to figure this out as not to repeat! :-[
There seems to be two issues here:-
Est Mash efficiency @ 76.60% Vs Measured Mash efficiency @ 67.60%
Est Attenuation @ 67.90% Vs Measured Attenuation @ 59.40%
You definitely need to calibrate your thermometer, hydrometer, and pH meter. The only other factor would be the mill crush if that could have changed.
I wouldn’t worry about iodine; the test is almost entirely subjective and you can get more repeatable results by measuring gravity during the mash (I’m assuming the Grandfather recirculates, which should make that pretty easy).
Because of the DME addition, I don’t think you can conclude there was a problem here from a single data point.
In my experience, mashing at around 68°C yields normal attenuations (75-85% ADF depending on yeast strain). I didn’t see any mention of the grist, so it could be that the base malt was under-modified and would have benefitted from a step mash - low conversion efficiency could support that, but again it’s hard to conclude anything from a single data point.
Calibration & Grain Crush - Have calibrated, will double check though! Grain crush remains the same.
Iodine - Interesting as a lot of resources highly recommend it? I always check pre-boil gravity, will check gravity during next time though to see where I’m at.
Attenuation - I thought so too, but when I enter the DME addition into Beersmith the Est Attenuation is 67.90%?
Yeast - Wyeast 1728 Scottish Ale - Est 218 Billion
Grist for 10 Litre Batch:-
Marris Otter Pale (5.9 EBC / 2.80 L) = 4621.79 g (89.90 %)
Crystal Malt Light (100 EBC / 39 L) = 229.26 g (4.50 %)
Honey Malt (49.30 EBC / 19.03 L) = 119.56 g (2.30 %)
Chocolate Malt Pale (525 EBC / 197 L) = 58.55 g (1.10 %)
Crystal Malt Extra Dark (340 EBC / 128 L) = 58.55 g (1.10 %)
Munich Malt (25 EBC / 10 L) = 54.86 g (1.10 %)
P.S. Checked carbonation levels again last night after 2.5 weeks at room temp. I think there’s a little more carbonation than last week and maybe a tad less syrupy? Tasting pretty good. Gave them a rousing! Maybe de-gas a bottle after another week and check gravity? Haven’t had The Sh#ts yet though!
154 may not be out of range, but mashing in >163* to me definitely is. Depending on how long it took to get down to 154* you could get a lot of enzyme fry, and little or no beta amylase activity, hence syrup.
