We have been brewing for over 10 years and never had a stuck fermentation. We have now had two in a row. Few facts. 1. Created 1.035 yeast starter using Wyeast 1056. In last four attempts they never got a krausen. We follow the process quite rigorously with bringing yeast to an room temp, smacking and let expand at 70f for 2-3 hours before pitching into starter wort. The yeast viability dates were all good. This summer we had yeast die in transit to Central Oregon. Remaining 3 starters were hand carried by me from cooler to my fridge. 2. What’s néw in our last two 15g batches is we used LME in the brew to adjust wort to OG target. Both were to be IPAs @ 1.065 - 1.067. 3. Temp control for all starters was 68-74. 4. We aerated wort on transfer into ferm. We didn’t have timing right so our pitch for both batches was several hours after transfer to ferm. 5. In both batches our gravity got stuck around 1.030 to 1.035. We repeated starter and pitched additional aerated yeast 6. We have let starters go on stir plates from 24 to 48 hours. Same negative result of stuck fermentation 7. The fermentater is temp controlled and never got below 66 and never above 72. 8. We use multiple measurement tools to measure gravity including Tilt and spectrometers. 9. There was no massive take off on the fermentation. Both batches took 3+ Days to get from 1.065 to 1.030. We ate perplexed and would love the wisdom of this community in what we did wrong.
I’m not anyone take advice from, so I’ll guess maybe it’s a mash issue not a yeast issue? Maybe you are making sugar the yeast doesn’t like? I don’t know how to say that more technically lol
Did you use a refractomter calculator (not a standard brix to SG converter) to adjust the refractometer readings? If not, the FG (in particular) is lower than you think is.
On the two "stuck ferments', were the refractometer and Tilt readings close to each other? Reason I ask is if they were close, and your adjusted refractometer reading is considerably lower than the pre-adjusted reading, your Tilt might need to be re-calibrated. Prior to the these two batches, were you using a refractometer & Tilt, or something else?
I’m leaning toward what @VikeMan is suggesting, that it maybe a misread. I have only used LME once in a stout but I didn’t take any readings. I do use DME now on big beers but I only use a hydrometer to read it .
And so... Did you use a refractomter calculator (not a standard brix to SG converter) to adjust the refractometer readings? With a refractomter calculator, you enter both the "OG" brix reading and the current brix reading together. If you're not doing that, your "FG" reading is way off.
If you didn't use a refractometer calculator and would like see if that's the culprit (as opposed to the beer not being finished) here's a link to one: https://www.morebeer.com/products/brewing-refractometer-dual-scale.html?a_aid=hbf (Scroll down to Refractometer Alcohol Correction Spreadsheet � For Beer) BrewCipher, (< link) available to download and use for free, is a powerful recipe builder and uses the same/similar calculator as the one referenced above. (VikeMan correct me if that's not right)
I just plugged the numbers in on the caculator I use (https://www.brewersfriend.com/refractometer-calculator/) and came up with, using OG of 1.067, FG at 1.030 |(close enough to 7.6 Brix) equals corrected FG of 1.009, 7.6% ABV. This is with no correction at all - which having backed up readings on my own brews with hydrometer ending up close enough for government work. OP|:| what was your expected FG? Did you sample the beer or just rely on the readings of gravity? There'll be a noticable difference between 1.030 and 1.009 - you'll be able to tell the sweetness immediately, versus the dryness if it is in fact finished.
nope. we have temp adjusted readings. i think it might be the dme. it's the one variable that looks sneaky.
Nobody asked if you have temp adjusted readings. I'll ask for the third time: Did you use a refractomter calculator (not a standard brix to SG converter) to adjust the refractometer readings? Also, why do you think DME is a sneaky variable? It generally makes a wort that's very slightly less fermentable than an equivalent all grain wort, but nothing that would cause problems.
I have never had any problems with my brix readings. 1.039 isn't even close to 1.06 which is target gravity so not sure we have conversion issue. I've used the same technique for dozens of batches and never once had a problem. The DME is a new variable. We use it to increase gravity when we don't hit target sugar level.
we aren't worried about the brix readings. From VikeMan: Did you use a refractometer calculator (not a standard brix to SG converter) to adjust the refractometer readings? If the answer is no, then I think you're probably done, and pretty close to your expected FG. You can read the brix on the fermented beer all you want, but it doesn't read accurately because of the alcohol, hence the adjustment calculator.
