Higher FG than expected...several things tried but I feel like I'm missing something more obvious here.

[jordo_99]

I've been using a propane kettle and cooler setup for the past 6 years but recently bought and fixed a Brewie B20 for it's automated brewing features.

I wanted to get the Brewie for it's multi-step mashing capabilities and all three brewdays have gone relatively smoothly as I'm hitting my volumes and my SG/OG numbers seem fine as well but my fermentation keeps stalling out around 1.023 on all three brews despite changing my mash each time to try and get a lighter body beer.


I've done the following beers and mash profiles...all 3 beers ended up at 1.023 or 1.024!

5gal Cream Ale (spotted cow clone)​

OG -- 1.046 (Est. 1.047)​

FG -- 1.024 (Est. 1.011)​

​

104F -- 30 min​

122F -- 30 min​

146F -- 30 min​

158F -- 30 min​

168F -- (60 min sparge)​

​

I just assumed my Kolsh wyeast packet was a dud and stalled out...Since it tasted fine, I just kegged and didn't bother trying to re-pitch more yeast or do an amaylze conver.

2.5gal Amber Ale​

OG -- 1.047 (Est. 1.050)​

FG -- 1.024 (Est. 1.014)​

​

104F -- 30 min​

122F -- 30 min​

146F -- 45 min​

158F -- 15 min​

168F -- (60 min sparge)​

For the amber ale, I got to thinking more about my mash schedule decided to increase the beta rest just in case there was something I'd overlooked but it ended up doing the exact same thing using S-04 yeast. I was still going for a balanced body but wanted to see what would happen here.

2.5gal Amber Ale​

OG -- 1.047 (Est. 1.050)​

FG -- 1.023 (Est. 1.014)​

​

153F -- 60 min​

168F -- (60 min sparge)​

With the second attempt at the exact same recipe as the last brew, I decided to just skip the fancy step mash and do a tried and true infusion mash of 153F...heated up the strike water and then just held it at 153F for an hour...fermented in a keg for 3 weeks and it still came out at 1.023


I'm now at a point where I'm not sure my mash schedule is the issue and I'm back to analyzing all the other factors in my recipe and brewday. I originally thought that a thinner mash would be better since I'm using a 2hr mash and I wanted to ensure I didn't convert all the starches before reaching the alpha range...Now that I've re-read the company's "recipe tips" I see they recommend a grist ratio of 1.3 for optimal efficiency -- I used 1.4 for the spotted cow recipe and 1.8 for the two amber ales.

I didn't have time to bother with PH for the two amber ale brews but with the first brew I showed 5.4 before making adjustments so I expected it to be fine.

I'm going to dig into a bunch of their default recipes to see what their mash schedules look like to see if I can figure out some of the tricks they may have worked out for this particular equipment.

Any suggestions on stuff to look into would be awesome

 

[VikeMan]

First things first: Did you recent;y switch from a hydrometer to a refractometer? If so, are you using a refractometer calculator to correct the readings?

If not, have you confirmed your mash temps with a known good thermometer?

 

[jordo_99]

You may have nailed it with the refractometer...I got one at the same time I bought the Brewie and have been using the refractometer the entire time.

As for the mash temps...I've been verifying the mast temps with thermometers throughout the brewdays and they're always spot on.

I'll definitely look into the refractometer conversion stuff...when I first tried it I did use my calibrated hydrometer to confirm the reading at OG but never at FG and just assumed the scale was reliable.

 

[VikeMan]

I'll definitely look into the refractometer conversion stuff...when I first tried it I did use my calibrated hydrometer to confirm the reading at OG but never at FG and just assumed the scale was reliable.

Refractometer OG only requires a small correction. FG requires a huge correction, and has to be calculated in conjunction with the OG reading. The numbers in your post are typical for this issue.

 

[jordo_99]

That's very interesting...I didn't realize the alcohol throws it off.

http://seanterrill.com/2012/01/06/refractometer-calculator/
Assuming that's a reliable calculator (I'll obviously want to find my calibration values...the default there is 1.040), I've hit all of my numbers all along and have been racking my brain for nothing!

Thanks a ton for the assist here!

 

[TheMadKing]

Refractometer OG only requires a small correction. FG requires a huge correction, and has to be calculated in conjunction with the OG reading. The numbers in your post are typical for this issue.

Agreed, I would go so far as to say that the calculations for trying to correct the FG result in numbers that are inaccurate enough to make this not worth the time. Just use a hydrometer to measure FG

 

[VikeMan]

Assuming that's a reliable calculator (I'll obviously want to find my calibration values...the default there is 1.040), I've hit all of my numbers all along and have been racking my brain for nothing!

Sean's is the best I've seen. I've incorporated it into my own software.

(I'll obviously want to find my calibration values...the default there is 1.040)

My implementation of Sean's calculator also recommends a "wort correction factor" value that varies depending on the expected fermentability of the wort. That feature is a work in progress, but others have told me it works well for them, and of course you can override it with 1.04 or anything you want.

 

[doug293cz]

Agreed, I would go so far as to say that the calculations for trying to correct the FG result in numbers that are inaccurate enough to make this not worth the time. Just use a hydrometer to measure FG

I haven't found this to be the case. When I compare my corrected (using Sean Terrill's spreadsheet) refractometer FG's against a hydrometer, I'm usually within +/- 0.003. I find this "good enough" most of the time. Each brewer needs to make their own decision as to what level of accuracy is good enough for them. If you want the best possible accuracy, use a limited scale hydrometer, rather than a wide range one.

Brew on

 

[day_trippr]

[...]Assuming that's a reliable calculator (I'll obviously want to find my calibration values...the default there is 1.040), I've hit all of my numbers all along and have been racking my brain for nothing! [...]

This happens all the time around here.
Anytime someone comes on with "my beers all stop in the mid-20s and 30s" that's the go-to question...

Cheers!

 

[jordo_99]

I find this "good enough" most of the time. Each brewer needs to make their own decision as to what level of accuracy is good enough for them. If you want the best possible accuracy, use a limited scale hydrometer, rather than a wide range one.

That's honestly how I feel about it too...I couldn't care less about ABV in almost every situation (it's still nice to know...I just care far more about flavor than alcohol) but I calculate the SG/FG values so I can try to confirm that my brewing processes/controls are working as intended.

 

[TheMadKing]

That's honestly how I feel about it too...I couldn't care less about ABV in almost every situation (it's still nice to know...I just care far more about flavor than alcohol) but I calculate the SG/FG values so I can try to confirm that my brewing processes/controls are working as intended.

Yep same here, but a FG hydrometer sample also is a good opportunity to taste the beer and make sure there are no glaring off flavors - I'm not familiar with Sean's spreadsheet, I was speaking from my experience using some other online calculators where the accuracy was more like +/- .006

 

[bracconiere]

i need to know FG with a hydro.... 1.003 would kill my calorie counting, and make me fat....

 

[couchsending]

On another note I wouldn’t really bother with all those steps for the beers you’re making.

Big fan of step mashing but unless you have a really whacky grain bill you really shouldn’t be doing those first two low temp steps with modern malts. They can potentially do more damage to your beer.

If you must do a protein rest 130-133 would be optimal to not kill foam but again unless your grain bill is a high percentage of something other than barley I’d start everything above 140. Bump the alpha rest up to 162 as well. You’ll get some additional benefits at 162 over 158.

 

[Brooothru]

I haven't found this to be the case. When I compare my corrected (using Sean Terrill's spreadsheet) refractometer FG's against a hydrometer, I'm usually within +/- 0.003. I find this "good enough" most of the time. Each brewer needs to make their own decision as to what level of accuracy is good enough for them. If you want the best possible accuracy, use a limited scale hydrometer, rather than a wide range one.

Brew on

^^^this

I have a set of three hydrometers that measure different bands of SG with expanded scales for my aging eyes. One measures 1.130-1.060, next 1.070-1.000, and finally the most useful 1.020-0.980. I tracked a bunch of batches and found (using propper calculators and wort correction factors) that my refractometer and hydros were always in agreement down to two decimals. The great thing about refractometers is only needing about 1ml vs. 1+ cup of wort to take a reading. I seldom ever pull out the hydros anymore.

Brooo Brother

 

[Brooothru]

On another note I wouldn’t really bother with all those steps for the beers you’re making.

Big fan of step mashing but unless you have a really whacky grain bill you really shouldn’t be doing those first two low temp steps with modern malts. They can potentially do more damage to your beer.

If you must do a protein rest 130-133 would be optimal to not kill foam but again unless your grain bill is a high percentage of something other than barley I’d start everything above 140. Bump the alpha rest up to 162 as well. You’ll get some additional benefits at 162 over 158.

I'll play DeviI's Advocate and disagree, at least slightly regarding step mashes. If you have the capability (i.e., Grainfather, Braumeister, et. al), why not use it?

While it may not be 'necessary' to perform some of the various steps, having dedicated rests for b-amylase and a-amylase can only improve your yields and efficiency while also allowing you to 'shape' the body of the finished beer. A single infusion won't achieve that level of control.

As I sit here typing I'm monitoring the mash of an Irish Red ale, using about 30% Best Malz Red-X in the grist. The recommendation of the head maltster is to specifically use a step mash not for yield but for color! Seeing examples of single infusion vs step mash with this particular grain is VERY different in appearance.

I do agree that a protein rest at ~131F would be detrimental to body and head retention and is unnecessary with today's modern malts. But a brief rest around 45C/113F has been shown NOT to degrade body or head retention, but does improve liquefaction and final clarity. The German Hoch-Kurz mash schedule often includes this rest.

My standard mash profile is:

40C-45C-63C-72C-76C
or
104F-113F-145F-162F-169F

for Dough-in, Beta Glucan, Beta Amylase, Alpha Amylase, Mash-out.

It ends up covering all the bases, hitting Beta and Alpha enzymes at their most active temperatures. Timing of those two rests is adjusted depending on whether I want to emphasize crispness or maltiness in the finished beer. Works quite well, but does end up taking about :30 - :45 minutes longer in the mash.

Brooo Brother

 

[couchsending]

I'll play DeviI's Advocate and disagree, at least slightly regarding step mashes. If you have the capability (i.e., Grainfather, Braumeister, et. al), why not use it?

While it may not be 'necessary to perform some of the various steps, having dedicated rests for b-amylase and a-amylase can only improve your yields and efficiency while also allowing you to 'shape the body of the finished beer. A single infusion won't achieve that level of control.

As I sit here typing I'm monitoring the mash of an Irish Red ale, using about 30% Best Malz Red-X in the grist. The recommendation of the head maltster is to specifically use a step mash not for yield but for color! Seeing examples of single infusion vs step mash with this particular grain is VERY different in appearance.

I do agree that a protein rest at ~131F would be detrimental to body and head retention and is unnecessary with today's modern malts. But a brief rest around 45C/113F has been shown NOT to degrade body or head retention, but does improve liquefaction and final clarity. The German Hoch-Kurz mash schedule often includes this rest.

My standard mash profile is:

40C-45C-63C-72C-76C
or
104F-113F-145F-162F-169F

for Dough-in, Beta Glucan, Beta Amylase, Alpha Amylase, Mash-out.

It ends up covering all the bases, hitting Beta and Alpha enzymes at their most active temperatures. Timing of those two rests is adjusted depending on whether I want to emphasize crispness or maltiness in the finished beer. Works quite well, but does end up taking about :30 - :45 minutes longer in the mash.

Brooo Brother

Did you not read my post? I am a proponent of step mashing. However I’m not a proponent of steps that are for the most part virtually worthless with modern malts.

There’s zero reason to rest at 104. It takes hours for that rest to work if your goal is acidification which would be the only reason to actually rest that low unless you’re using some seriously under modified malt with crazy high beta glucan content.

Fine you could rest at 113 if you wanted. However you are gaining so very little plus adding a serious amount of time to your brew day by not only resting at that time but also the time it takes to go from 113 to at least 140, especially with these small electric brewing systems (I have a grainfather). Even if the temp gauge says you’re at X temp after a step turn the heat off and the pump and see how far the temp falls. In my experience it takes the grain bed a lot longer to reach the desired temp than the temp gauge would indicate.

Too there’s just as much data out there now that would say you’re creating a fair amount of stalling compounds by doughing in at any temp below 140.

If you have the ability to step easily I recommend it as well. Separate beta and alpha rests can be beneficial as well as a full mashout step.

 

[Brooothru]

Did you not read my post? I am a proponent of step mashing. However I’m not a proponent of steps that are for the most part virtually worthless with modern malts.

There’s zero reason to rest at 104. It takes hours for that rest to work if your goal is acidification which would be the only reason to actually rest that low unless you’re using some seriously under modified malt with crazy high beta glucan content.

Fine you could rest at 113 if you wanted. However you are gaining so very little plus adding a serious amount of time to your brew day by not only resting at that time but also the time it takes to go from 113 to at least 140, especially with these small electric brewing systems (I have a grainfather). Even if the temp gauge says you’re at X temp after a step turn the heat off and the pump and see how far the temp falls. In my experience it takes the grain bed a lot longer to reach the desired temp than the temp gauge would indicate.

Too there’s just as much data out there now that would say you’re creating a fair amount of stalling compounds by doughing in at any temp below 140.

If you have the ability to step easily I recommend it as well. Separate beta and alpha rests can be beneficial as well as a full mashout step.

I'm not resting at 104F. That's just the temperature I mash-in. The rest at 113F is more of a pause (10 mins) on the way to 145F for b-amylase. As you stated, these electric kettles take their time getting from room temperature to 145F. For me it's about :15 mins., depending on ambient conditions, so a 'pause' at 113F is likely of little consequence in the larger scheme of things either in producing staling elements or improving liquefaction. I will note that I've never had a stuck sparge even when using an abundance of wheat or oats in the grist, and my mash numbers are consistently accurate.

I generally mash-out for :15 minutes. Do you find it beneficial to go longer? I usually get about a gallon of 1.020 wort when I sparge that gets used for the next starter yeast. Am I leaving too much behind?

Brooo Brother

 

[jordo_99]

I'm really enjoying the back and forth here; I'm seeing a lot of great information to go research...we can't learn something new until we realize what we don't know!

As far as my mash schedule is concerned...it sounds like my 104/122F rests are overkill and my alpha rest should be raised to 162F.

This was really helpful and I appreciate the advice a great deal!

 

[Brooothru]

I'm really enjoying the back and forth here; I'm seeing a lot of great information to go research...we can't learn something new until we realize what we don't know!

As far as my mash schedule is concerned...it sounds like my 104/122F rests are overkill and my alpha rest should be raised to 162F.

This was really helpful and I appreciate the advice a great deal!

I agree. The points brought up by @couchsending piqued my interest. I've always mashed-in between 95F-110F because that's how I started out years ago. I'm guessing it was probably something I read about and just started doing. There's probably no reason for me to mash-in that low, and maybe some valid reasons why not to. It's gotten me to do some more research and maybe modify my ingrained procedures. "Just because we've always done it that way" is a poor excuse for not keeping a mind open to change.

Brooo Brother