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RevFrank

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5.5 gallon Winter Lager recipe using 14.75 pound grain bill. The recipe predicted OG 1.072 and a FG of 1.016 at my more normal than not 73% brewhouse efficiency. As I brewed, I was hitting the numbers. My fermenter started working on 5.5 gallons at the OG. On the nineth day in primary, I hit the estimated FG. Rather than move to secondary, I elected to stay in primary, with the intent to do a cold crash, follow with a gelatin adjunct then move the beer to the keg for lagering. Fermentation, using WLP830, has been in a temp controlled box at a constant 53F. Yesterday, I started the cold crash, adjusting the control to reduce temp to about 34F, a process that takes about 30 hours to achieve. This morning, I checked on it and noticed that the temperature has dropped to 47F and still falling but that the FG dropped 8 points!, now sitting at 1.008 and stable. Since OG hit the numbers at 73% efficiency, how can my FG be so far off (in a good direction, mind you!)? Is it the attenuation of the yeast? (76.5% listed average and this one is 88%) I'm lost to understand this but not so much as I won't drink it! What are your thoughts?
 
I assume you made corrections for temperature, and that there were no bubbles clinging to the hydrometer the first time. If it tastes good, drink it, and chalk it down to the magic of yeast.
 
What was your mash temp? Is it possible your mash temp settled significantly lower than intended?

Did you use a different yeast that what the recipe called for or what you planned on at first?

As I was told recently, yeast will do whatever the heck they want to do in a fermentation, the numbers given as far as apparent attenuation are just estimates or averages. 88% is an awfully high attenuation though.... Are you sure the beer was sitting at 1.016 for a few days or did you only check it once?
 
What was your mash temp? Is it possible your mash temp settled significantly lower than intended?

Did you use a different yeast that what the recipe called for or what you planned on at first?

As I was told recently, yeast will do whatever the heck they want to do in a fermentation, the numbers given as far as apparent attenuation are just estimates or averages. 88% is an awfully high attenuation though.... Are you sure the beer was sitting at 1.016 for a few days or did you only check it once?
Mash temp 154F
Mashed in 10 gallon cooler. temp gradually cooling.
Same yeast as planned in recipe

Did constant monitoring using Tilt ... chart appended



chart.jpeg
 
Mash temp 154F
Mashed in 10 gallon cooler. temp gradually cooling.
Same yeast as planned in recipe

Did constant monitoring using Tilt ... chart appended



View attachment 596380
Yeah then not sure man. Someone else smarter than me will have to chime in.

On a side note, that's a nice use of the tilt! I never even thought about that! Totally doing that on my next brew in a couple of weeks.

Just calibrate temp and drop it in the mash? Any tricks to it?
 
Yeah then not sure man. Someone else smarter than me will have to chime in.

On a side note, that's a nice use of the tilt! I never even thought about that! Totally doing that on my next brew in a couple of weeks.

Just calibrate temp and drop it in the mash? Any tricks to it?

No tricks. Doesn't need calibration as far as I can tell. I've used it in 4 brews so far. I love it!

I set up the monitor by using an old tablet ... It must have Bluetooth low energy (BLE), aka bluetooth 4. It's built-in in android 4.3. The tablet takes a BLE reading every so often and sends it to a free charting website you open at www.brewstat.us. Because its on the net, I check in anywhere and any time from a net connect. On the last brew, I was out of town and still tracking it and saw I needed to give it attention on my return.
 
I find my TILT gets wonky when I cold crash. A few beers ago my TILT showed I was around 1.001 or something so I thought I had an infection. Nope! All normal when I took a hydro sample.

I bet if/when you take a hydro sample it will be closer to your expected FG.
 
I find my TILT gets wonky when I cold crash. A few beers ago my TILT showed I was around 1.001 or something so I thought I had an infection. Nope! All normal when I took a hydro sample.

I bet if/when you take a hydro sample it will be closer to your expected FG.
Yeah mine was just way off on an Imperial stout. It was reading 1.045 for a week so i thought it was stuck. I added 2 packs of rehydrated 05 and still nothing. Pulled a hydro sample and it was 1.034...
 
Yeah mine was just way off on an Imperial stout. It was reading 1.045 for a week so i thought it was stuck. I added 2 packs of rehydrated 05 and still nothing. Pulled a hydro sample and it was 1.034...
Interesting ... something to watch, I guess. I did a hydro sample at the end and it verified the low 1.008 ... which is 8 points lower than the recipe calculated 1.016 FG
 
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