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Consistent 1.006 FG

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wsmith1625

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My last few beers have all been coming up with a low final gravity. The funny thing is they are all landing at the same spot, 1.006. I have no idea why I am unable to hit my target final gravity anymore. I used to be very consistent at hitting 1.010 and I don't know what changed. I started looking at my notes and unfortunately I don't always record my FG, so I don't know exactly when this problem started. I am very meticulous about sanitation and always wash my gear with Oxyclean and sanitize with StarSan. Also, no visible signs of infections or off flavors.

I switched to BIAB brewing this year and have had a lot of success with this method. My mash temperatures are typically between 150 and 152 and temperature drop is 2 degrees over an hour. I even mashed my last batch at 152 despite the recipe calling for 150 just to be sure I wasn't too low.

I also calibrated my hydrometer and it's reads 1.000 in room temp water.

Overall, I have been making delicious beer, but I feel I am on the dryer side and missing some of the malt sweetness. I am planning to brew a few malt forward beers for the fall and don't want them turning out too dry. Any ideas on what can be causing this issue?
 

Coastalbrew

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What is the calibration temperature for your hydrometer? Most hydrometers are calibrated @ 60* F. Also what yeasts are you using? Is it possible you have a var. diastaticus infiltration happening?
 

kh54s10

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For me .004 is close to my acceptable error factor in just reading the gravity. But I would be surprised that every recipe is truly exactly 1.006. I can't imagine that happening. I would look for the calibration temperature of the hydrometer, it is usually printed on the paper scale inside the bulb. Calibrate you thermometer. Then try a bigger change in mash temperature. I would go to 154 (maybe even a bit higher) for a malty recipe.
 
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wsmith1625

wsmith1625

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My hydrometer calibration temp is 60* and it reads 1.000 at that temp. My samples are not at 60* though. I am fermenting at 68* took a reading straight from the fermenter. Let me get another sample and cool it to 60*.
 

rsquared

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My hydrometer calibration temp is 60* and it reads 1.000 at that temp. My samples are not at 60* though. I am fermenting at 68* took a reading straight from the fermenter. Let me get another sample and cool it to 60*.
The conversion from 68 to 60 only adds 0.001. You can use a calculator for other temps, but if you're typically reading at around 68, you can just keep that number in mind.
 
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wsmith1625

wsmith1625

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Yup, second test was 1.007, so the temp conversion was sufficient and I'll use it going forward. Thanks for sharing that.

I still wish I knew why the FG is lower than expected. Besides raising the mash temperature, which I did on the last brew, I cannot thing of anything else I can do to fix this.
 

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Yup, second test was 1.007, so the temp conversion was sufficient and I'll use it going forward. Thanks for sharing that.

I still wish I knew why the FG is lower than expected. Besides raising the mash temperature, which I did on the last brew, I cannot thing of anything else I can do to fix this.
Are you repitching the same yeast? Checking mash pH? Calibrating your mash thermometer? Changed malt brands?

Those are the things I can think of that would impact this.
 
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wsmith1625

wsmith1625

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Are you repitching the same yeast? Checking mash pH? Calibrating your mash thermometer? Changed malt brands?
Last 2 brews have been fresh packets of dry yeast. Previous brew was BRY-97 and this one was US-05. I don't check my mash PH. Just use my tap water filtered through the fridge carbon filter and then treated with a 1/2 campden tablet. I do treat my total water volume, not just the strike water. For the malt brands, I guess they have changed. I buy all grain recipe kits and mill the grain myself. Last 2 kits were from Atlantic Brew Supply and the 2 before that were from Great Fermentations.

Most of the hydrometers I've seen over the past decade or so have been calibrated at 20C (68F). When in doubt, look at the bottom of the internal paper slip. It's usually stated there.
Yes, the paper slip on my hydrometer says it's calibrated to 60*. It's a Brewers Edge and probably about 6 yrs old. I don't think my reading are inaccurate. Definitely getting a low FG.
 

rsquared

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You've skipped the thermometer calibration question twice now... Have you checked that your mash thermometer is reading correctly? Mix up ice with a little water and it should read 32f. Then check that it reads 212f in boiling water.

If it's not right, mashing a few degrees low could be giving you a more fermentable wort.
 
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wsmith1625

wsmith1625

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You've skipped the thermometer calibration question twice now... Have you checked that your mash thermometer is reading correctly? Mix up ice with a little water and it should read 32f. Then check that it reads 212f in boiling water.
I originally thought it was a temperature/thermometer issue. Around 5 batches back, I took my mash temperature with my dial thermometer and thought I was dead on at 152. Then I checked with my digital and got a 4* lower reading. When I was done brewing I calibrated my thermometers and it was the dial thermometer that was reading high and the digital was correct. I calibarated the dial thermometer but didn't trust it much after that. I replaced it with a Thermoworks RT610B-12 digital thermometer. I checked the calibration when I received it and it's dead on.

So I have the Thermoworks RT610B-12 to get strike water and mash temp readings and use a Lavatools PT09 for most cold side readings. Both are excellent thermometers and highly accurate.



 

day_trippr

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I second the T'works RT610B. I have been using the 24" long version for a handful of years now for checking temps in my 20g 3v2p system vessels and it has proven itself trustworthy...

Cheers!
 

dmtaylor

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I originally thought it was a temperature/thermometer issue. Around 5 batches back, I took my mash temperature with my dial thermometer and thought I was dead on at 152. Then I checked with my digital and got a 4* lower reading. When I was done brewing I calibrated my thermometers and it was the dial thermometer that was reading high and the digital was correct. I calibarated the dial thermometer but didn't trust it much after that. I replaced it with a Thermoworks RT610B-12 digital thermometer. I checked the calibration when I received it and it's dead on.
Sounds like you have done everything right. Maybe just start mashing at 155 F. Or, try a less attenuating yeast (both BRY-97 and US-05 attenuate high). You might have better luck with Nottingham. Or try London ESB, it's my new favorite, and fermented cool it is actually very clean.
 

Jayjay1976

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Sounds to me like a diastaticus infection, explains the consistently low FG. I had a similar streak after brewing with a diastaticus saison strain. Bleach soak all your fermentation gear then give it a good airing out. Hand scrub all threads, crevices, etc. with a toothbrush and use a sponge inside the fermenter if possible. Some diastaticus strains form a stubborn biofilm which must be physically removed to get rid of it entirely. Good luck.
 
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catalanotte

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Have you made any Saisons lately. I know BE-134 is diastaticus as are some others, and can stick around for a while as @Jayjay1976 mentions. I found crud inside the valve on my siphonless BMB fermenetors, even after many wash/rinse cycles. Had to take it apart.
 
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wsmith1625

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I haven't brewed any Saisons or sours, just Pale Ales, IPAs, and a Kolsch. I think it's definitely a good idea to do the bleach soak to kill any possible contaminants and will probably do so as a precaution.

I did replace my fermenter bucket with a Fermonster which I converted to do closed pressure transfers, thanks to the great thread posted by Dgallo. I also replaced my 2 piece ball valve with a new 3 piece. I replaced the weldless bulkhead, dip tube, and ball valve, so basically all new kettle fittings. I've used the Fermonster for my last 2 brews, and the new ball valve on my last brew. The only piece that I haven't changed and have been using since I began brewing back in 2014 is my transfer hose.

I have always soaked the transfer hose in hot Oxyclean solution to clean it and StarSan to sanitize, but I have definitely gotten my moneys worth from that 3 feet of tubing. It's going in the trash today so I can use a fresh one for my next brew.
 

catalanotte

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If the system is clean and measurements are calibrated and accurate, the only other thing you could look at is mash/sparge process. Are you spending too much time in the lower temp range that is creating more fermentability in the wort than desired? Do you perform a mash out? I think you mentioned BIAB, which I have not done, so not very familiar with the mash out/sparge process, but getting that mash/wort up to 168 as quickly as possible after your last mash step may help. Good luck, I went through a couple batches of an amber ale that kept finishing at 1.008 or so and was pretty frustrated. It got much better up around 1.013 or so. The fix for me was in the management of the time and temperature after the initial infusion step.
 
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wsmith1625

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My last batch was a Pale Wheat which I mashed at 152* for 75 minutes. When the 75 minutes was up, I took a temp and was at 150* which I thought was good. Then I pulled the bag and transferred it to a bucket for a dunk sparge and started heating the kettle to a boil. I poured my 2 gallons of 168* sparge water over the grains and gave them a good stir and and a few dunks up and down. Then I hung the bag back over the kettle to fully drain while I added the sparge water into the kettle.
 

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IMO, 1.007 is a good thing. Enjoy your well attenuated beer!
 

TheMadKing

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My guess is that the switch to BIAB is causing it.

I used to BIAB and my FG was consistently 1.007 to 1.010 and when I switched to 3-vessel HERMS I found that I had far more control over my FG. The thinner mash and steadily dropping mash temp seemed to result in maximum fermentability in all of my worts, no matter what I intended. You could try mashing higher, like 156F and using multiple infusions to keep mash temp up, and then a mashout.
 
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wsmith1625

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You could try mashing higher, like 156F and using multiple infusions to keep mash temp up, and then a mashout.
Yeah, my gut tells me it's a temperature issue. I would like to do multiple infusions at some point, but want to get the single infusion process worked out first. I usually cover the kettle and set a timer for the full mash duration, not taking temperature readings mid way to avoid heat loss. Do you think I should get a temp reading mid way and apply heat if there's a drop? A little more work than my set it and forget it method, but just to test my processes.
 

VikeMan

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Yeah, my gut tells me it's a temperature issue. I would like to do multiple infusions at some point, but want to get the single infusion process worked out first.
If you're getting higher than desired attenuation with a single infusion, step mashing is probably not the solution, as step mashes tend to produce more fermentable worts than single infusion mashes.
 
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TheMadKing

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If you're getting higher than desired attenuation with a single infusion, step mashing is probably not the solution, as step mashes tend to produce more fermentable worts than single infusion mashes.
Agreed, I didn't mean to imply a multi step mash, but rather using multiple infusions of hot water to maintain the temperature at a steady temp
 

Jayjay1976

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My guess is that the switch to BIAB is causing it.

I used to BIAB and my FG was consistently 1.007 to 1.010 and when I switched to 3-vessel HERMS I found that I had far more control over my FG. The thinner mash and steadily dropping mash temp seemed to result in maximum fermentability in all of my worts, no matter what I intended. You could try mashing higher, like 156F and using multiple infusions to keep mash temp up, and then a mashout.
I had this issue for a long time before I realized that the probe near the bottom of my kettle was consistently reading about 8 degrees higher than the actual mash up above. This was causing higher attenuation than I wanted and some bland, bitter beers. I'm looking for a long-ish probe I can drop through the lid into the mash, until then I set the controller higher to compensate.
 
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