Seeking some advice on a topic I am sort of stuck on. My past 3 batches, 1 of which is on day 5 of fermentation, have ended with a significantly higher FG than expected. For the first batch, I used harvested yeast (did not make a starter with it) and it was roughly a month old. It fermented down to 1.020 after 14 days. I was expecting between 1.012-1.014. The second batch was a white ipa using WLP400. I used Mrmalty.com to get the correct pitching cell count and made a starter. Again, after 10 or so days, it fermented down to 1.019. Was expecting 1.010-1.012. The third and current batch is in the fermentation chamber. I brewed the Julius clone from the BYO magazine. I used harvested yeast, but made a starter with it. After 5 days, it is at 1.032. Will this end up being much higher like the rest? I am stuck as to where this is all going wrong. I ferment in a temperature controlled freezer at around 68 degrees F. Any and all help/suggestions would be greatly appreciated. Very frustrating when brew day goes off with no issues and fermentation kills it all!. I must mention that all 3 batches had an OG in the 1.060’s. The julius clone that is on day 5 had a OG of 1.064/1.063
Have you calibrated your hydrometer? Sometimes the paper inside can slip up/down and then you will always get readings that are off by however much it slipped. Try just measuring some room temp water and see if it comes in at 1.000 or if you get 1.005 or something. I had this happen, I was very confused by it for a while until I figured out what was going on.
I did read up on that and I did try some room temp water after the 2nd batch. It came in perfect at 1.000. It is calibrated for 68 degrees. I will double check again and see if it works properly. It is also worth mentioning that my wort that I use for my yeast starter always ends up in the 1.030 to 1.040 range. Never over .040
Yup, Hydrometer is fine… came in right at 1.000 with room temp water. Does this batch of beer have any shot and continuing to ferment down to the teens? It was still bubbling today and definitely high krausen at the top.
If you are doing all grain brewing, is your thermometer calibrated correctly (as in, you aren’t mashing at 165 and not knowing it are you)?
Do you have temperature control for your ferment? If the temperature is dropping as fermentation slows down a bit, the yeast might be giving up and dropping out. If you can warm up the fermentor a few degrees when the krausen starts to drop you will decrease your likelihood of that happening.
Also, do the other batches taste right? If the yeast got cool and gave up then there would probably be some fermentation off flavors in there (butter, green apple).
Yes Nate, these were all grain batches. I use 2 different thermometers and the mash temps end up being where I need them. The first to batches were at 150, the one fermenting away now was at 154. I don’t believe that temp during fermentation is an issue. I did just warm it up to 71 degrees. I have a probe taped to the bucket and I have a ferm wrap on the other side of the bucket. The first batch was a simcoe/amarillo ipa with london ale 3 yeast. It came out tasting way too sweet/malty. My guess is cause of the high FG. The white ipa using WLP400 actually came out pretty good. The FG bothered me still and I was hoping this wasn’t going to become a trend. The current batch is also using London ale 3. Harvested then made a 1.4 ish liter starter. I did taste the sample from today and I didn’t detect any real off flavors? But then again… I am not a professional judge. Nothing blaring about the taste though.
Unless you’re WAY off, mash temp may not make a huge difference. First question is, what lead you to expect those FGs? Have you made those recipes before? Second, let’s see the recipes. That’s often the cause of it. If not, at least we can rule it out.
All grain. First batch and most recent batch was mostly 2row. The most recent batch was 11.2 pounds of 2row, .5 pounds of honey malt, .5 pounds of carapils, .75 flaked oats and 8ozs of turbinado sugar.
I believe the simcoe/amarillo was roughly 12 pounds of 2 row, roughly 1/2 pound of crystal 20 and a pound of flaked oats.
The white ipa was 8 pounds pilsner malt, 4 pounds of 6 row, 1.75 flaked wheat.
Honestly, the only other thing I could suspect… Could it be the crush of my grains? I recently bough a barley crusher and I am trying to recall if I used it prior to the past 3 batches… I started to think that it is milling the grains a little too fine? Would that potentially be an issue even though the OG is where it should be?
I’ve never heard of grain crush size affecting fermentability, not to say that it can’t. I think that it mainly just changes the efficiency that you get. For sure, I’ve never seen any change from crush size (I usually grind pretty fine).
From the recipes, I would expect them to ferment down to the mid to low teens.
Right. So considering temp really isn’t an issue. It has to do with my pitch rate? What could I potentially do differently? The crazy thing is I have made 4 or so starters prior these last 3 batches and they all had no issues with fermenting down properly.
I am going to guess, that I decanted some of the yeast. I am pretty sure I cold crashed the last 3 batches of yeast starters and either the yeast didn’t completely settle out or I decanted some off of the bottom. If that isn’t it, than I have no idea what my issue is. I am going to rebrew the white IPA next week and if that ferments down lower than the first time, than I will know I have solved the issue. Fingers crossed.
You might want to check the thermostat that’s controlling your fermentation chamber if it’s not reading correctly like an independent thermometer inside you could be cooling down below optimal temperatures and making the yeast sluggish
I wonder what the temp is inside the freezer… Controllers may give a few degrees leeway before kicking in. If the temp is getting really high it might make a difference. Heat transfer from air is slow. Maybe have some wet towels pre chilled to wrap or set it in water or even just have a a few gallons further water in there. I used to cool in a fridge run off a crude controller & it was pitiful to hear the controller start the fridge off/on every 3 minutes during krausen.
Are you taking the final gravity readings with a Hydrometer or a refractometer? If you are using a refractometer and not using an adjustment calculator that could explain the high readings.
Just a little update for those who are interested. I am fortunate to have a smaller chest freezer (roughly 5cb ft) for cold crashing and hopefully lagering soon) and a larger 8footer. With that, I have to Ink bird temp controllers. One of them I purchased over the summer, while the other I just got no more than 2 months ago. I decided to swap them and crank the heat up to 71. I also gave the bucket a gentle swirl. It took off for 24 hours much like an active fermentation would look like. I will take a hydrometer reading tonight since it would of been over 48 hours since my last reading. I also need to look at a more “accurate” way of taking temp for the controller. I currently have a heavy duty paper towel that is folded up to about the size of half of a dollar bill, duck taped around the edges while leaving just enough room to slide in the temp probe. Any better suggestions?
Maybe you could start fermentation a few degrees lower and raise it a degree a day over 5 days of so. I’ve had good results improving my attenuation that way.
So last night was Day 8 after pitching yeast. I first said it fermented down from 1.063ish to only 1.032. After jacking up the temp to 71 and giving the bucket a couple swirls here and there, it has fermented down to roughly 1.017. Dry hops added and will be kegged by Sunday morning. Maybe might fall a couple points? I will live with 1.015/1.016. Fairly strong green apple smell now. I assume after conditioning in the keg it will dissipate.
I use a combination of 1/2" foam pad, 1" thick styrofoam, and a bungee cord to hold the temperature probe to the side of the fermentor. The styrofoam has a narrow channel cut into it to protect the probe from excess pressure exerted by the bungee cord. The piece of foam padding is against the carboy with the more rigid styrofoam completing the seal from the temperature of the ambient air.