High FG - All-Grain Brown Ale

[Brew_G]

Folks...

I know these questions about high FGs have been asked a million times, but obviously not everyone's situations are the same, so here's an issue I'd like to throw out to the HBT collective for feedback.

Here's my process:

19 days ago: Brewed BIAB brown ale that came out with a higher OG than expected (1.066 v expected 1.062)
5 days ago: Started cold crash
3 days ago: Fined with gelatin and continued crash
1 day ago: Bottled and checked FG at the same time - FG 1.021 (expected was ~1.016)

I foolishly didn't take a gravity reading before cold crashing. That's something I'd normally do, but I was lazy and didn't do it because I figured I'd be just fine letting it ferment out for 14 days. With this strain, I've always been at FG in under a week. I was also dumb in that I continued with bottling after taking that 1.021 reading!

I made a starter of harvested Bell’s yeast a few days prior to brew day, let it crash, then decanted most of the spent wort. Night before brew day, I added about 1L of 1.036 wort and set it back on the stir plate and let it run for about 12 hours, then pulled it from the stir plate and let it sit for a few hours, at which point I pitched it into 66F wort. It was pretty much at high kräusen at that point. I use a 30L Speidel, so I rely on the airlock for indications of fermentation – airlock activity started within 8 hours.

My intent was to hit mash temp of 154F, but I got up to 156F, and it took about 8 minutes of stirring to get it down to 154F (it was hot on my brew day!). That said, I’ve mashed at 157F before with Bell’s yeast and got about 75% attenuation. Edit: That was actually 71% attenuation.

Fermentation took place at 68-69F. At day 4 of fermentation, I bumped the temp to 70F, then raised it by 1-2F every 12 hours, up to 76F, where it stayed for about 5-6 days. No signs of active fermentation at that point. I then proceeded with my cold crash.

Now…this is yeast that I split out from a starter about 5-6 months ago and has been sitting in jelly jars in my fridge ever since. I’m wondering if this could be the reason for the low attenuation. Is that possible, even though the starter fermented nicely and I pitched a healthy amount of yeast at (close to) high kräusen? I generally get 77% attenuation with this strain (give or take a couple percentage points), so the 67% I got on this obviously seems funky.

I’m pretty nervous that I got hasty and bottled this one waaaaay too early, so hopefully I can make any necessary adjustments based on feedback I get from you folks!

TL;DR: I bottled at 1.021 after 14 days of fermentation at proper temps. Did I 'eff up?

 

[kh54s10]

My guess is that you are fine, but 1.021 is a concern.... The high mash temperature is most likely the culprit, though it doesn't seem that high. You said that you have used the yeast at 157 degrees, similar recipe? Darker brews give more unfermentables which will increase the FG but it shouldn't be that high.

Without taking 2 fg readings there is no way to be totally certain that your fermentation was finished. If you are still concerned put the bottles in a storage box in case they explode. Chill and test a bottle at a week to see if they are getting seriously overcarbed. Keep checking them periodically.

Usual questions: Have you checked the calibration of your thermometers, hydrometer? What was the temperature of your sample? You didn't use a refractometer for your FG did you?

 

[Brew_G]

My guess is that you are fine, but 1.021 is a concern.... The high mash temperature is most likely the culprit, though it doesn't seem that high. You said that you have used the yeast at 157 degrees, similar recipe? Darker brews give more unfermentables which will increase the FG but it shouldn't be that high.

Without taking 2 fg readings there is no way to be totally certain that your fermentation was finished. If you are still concerned put the bottles in a storage box in case they explode. Chill and test a bottle at a week to see if they are getting seriously overcarbed. Keep checking them periodically.

Usual questions: Have you checked the calibration of your thermometers, hydrometer? What was the temperature of your sample? You didn't use a refractometer for your FG did you?

Good questions...

The 157F mash was on an American Wheat, so definitely a different grain bill. I just checked my notes and it looks like that went from 1.057 to 1.016, for an attenuation of 71%. Interesting...

Here's the grain bill for the brown:

10.5 lbs Maris Otter
1.00 lb C60
0.75 lb Victory
0.50 lb Chocolate
0.50 lb Rolled Oats
2 oz Acidulated Malt

My thermometer was calibrated insofar as it read 213F when the boil really got going. This is standard. I calibrated it a couple months ago in ice water and it read 32F.

Having reviewed my notes on the American Wheat, I'm now wondering if maybe my initial mash temp before stirring was even higher than 156F.

I use a hydrometer (not a refractometer) which is calibrated for 60F. I measured the sample at ~60F, and after the high FG reading, I checked the hydrometer against a reading in plain water at 60F. It read 1.000. I didn't let the FG sample sit, and it did have a little carbonation in it, though that *shouldn't* account for such an anomalous reading, should it? Strangely enough, the sample didn't seem overly sweet or thick when I drank it.

Yeah...I realize my mistake on not taking two readings. I honestly knew it as soon as I saw that high FG reading, but I continued with bottling anyway. I'm thinking of moving the bottles to a safer place in the basement in a few days, just to be sure.

Good call on testing a bottle in about a week. I'll have to drink a beer.

 

[IslandLizard]

A 1 liter starter doesn't give you enough yeast for that batch. It also depends on the viability of your old saved starter after 6 months, so your first step may have been short already.

I'd say there's a good chance you underpitched by quite a bit, and that's why it didn't attenuate as much as expected. Then 2 weeks fermentation can be a bit short too, it may have gone down a few more points over the next 2 weeks. Did you oxygenate well when pitching?

 

[tim_c7]

Hey Brew_G. It looks like a mighty fine beer. The only way to tell if you F'd up is to know the terminal gravity of your wort before bottling ....or to send me a six pack .

You mention the difficulties in maintaining mash temp, did you perform an iodine test to ensure starch conversion? Perhaps that is why your gravity is higher.

Also take a look at the link http://www.winning-homebrew.com/forced-fermentation-test.html on performing a test to get terminal gravity.

I hope this helps in the future.

 

[Brew_G]

A 1 liter starter doesn't give you enough yeast for that batch. It also depends on the viability of your old saved starter after 6 months, so your first step may have been short already.

I'd say there's a good chance you underpitched by quite a bit, and that's why it didn't attenuate as much as expected. Then 2 weeks fermentation can be a bit short too, it may have gone down a few more points over the next 2 weeks. Did you oxygenate well when pitching?

Sorry if it didn't come across correctly, but that was a second step up. Here's what I did:

• Started with approximately 25-30mL of slurry in a 250ml jelly jar with spent wort covering it
• Pitched that slurry into 1.5L of 1.036 wort and set on stir plate for about 30 hours
• Crashed 1.5L starter for 72 hours and decanted to about 250mL
• Night before brewday, added 1L of 1.036 wort to the flask and popped onto the stir plate
• Took starter off stir plate at around mash in and swirled occasionally - kräusen was definitely up there
• Pitched full starter at ~66F

The first step yielded a pretty healthy amount of yeast. I was actually surprised at how healthy the yeast seemed to be after that amount of time. That second step in getting it to high kräusen probably led to an overpitch, but I wanted to try something new.

 

[joshesmusica]

Well there's no reason you should be getting that high of a temp with boiling water, unless you're somehow in an over-pressurized chamber when brewing?
Are you letting it rest on the bottom when measuring that?
If that is the temp of the water then your thermometer is actually reading too high at warmer temps. Which makes your fg conundrum even more of one, as you could be reading as much as 1 degree high.

 

[Brew_G]

Well there's no reason you should be getting that high of a temp with boiling water, unless you're somehow in an over-pressurized chamber when brewing?
Are you letting it rest on the bottom when measuring that?
If that is the temp of the water then your thermometer is actually reading too high at warmer temps. Which makes your fg conundrum even more of one, as you could be reading as much as 1 degree high.

That'd be kind of cool to brew in a pressure chamber.

I clip it to the lip of the kettle. It's a candy thermometer, so it's designed to handle those high temps.

I figured that it would read that high because I reach boiling at 212F (or maybe just slightly less), but there's some sort of buffer that allows the temp to rise a degree or two as it boils violently. If that's not correct, then I need to check my thermometer again in some ice water!

So if I'm actually reading 1-2 degrees high, then I could potentially have had mash temps of up to 158F before the stirring brought my temp down to what I thought was 154F (but may have actually been 156F). That would go some way to explaining things...

 

[joshesmusica]

I was confused about that as well. The wort doesn't really add enough to allow the boiling point to jump that high. I found an article once that talked about it. If you were at sea level and it was a normal sized wort it would read like 212.2 or something like that. Boiling point is a deep subject to talk about actually because there are different variables that affect it. But either way you're not gonna be at 213. So maybe you're actually boiling at 210, which would mean at boiling your thermometer is off by 3 degrees. I'm not sure if that is gonna be sorta like some slope algorithm though. If it is you can guess that you're thermometer is telling you 1-2 points higher than actual temp. So it's the opposite of what you're saying. So if your thermometer was reading 156, you were more than likely at 154-155. That's why I said it would only add to the conundrum.

 

[Brew_G]

I was confused about that as well. The wort doesn't really add enough to allow the boiling point to jump that high. I found an article once that talked about it. If you were at sea level and it was a normal sized wort it would read like 212.2 or something like that. Boiling point is a deep subject to talk about actually because there are different variables that affect it. But either way you're not gonna be at 213. So maybe you're actually boiling at 210, which would mean at boiling your thermometer is off by 3 degrees. I'm not sure if that is gonna be sorta like some slope algorithm though. If it is you can guess that you're thermometer is telling you 1-2 points higher than actual temp. So it's the opposite of what you're saying. So if your thermometer was reading 156, you were more than likely at 154-155. That's why I said it would only add to the conundrum.

:smack:

Of course! I completely misinterpreted that.

Ugh. Now I'm really wondering WTF happened!

 

[Brew_G]

I've been thinking about this since yesterday, and I'm wondering whether the low attenuation has to do with "tired" yeast.

Is it possible that the yeast sitting in my fridge for that long simply didn't have the strength to fully ferment a 1.066 wort mashed on the higher end, even though the starter produced plenty of seemingly healthy new cells?

 

[joshesmusica]

If they fermented out the starters, they were likely pretty healthy. Did you check attenuation on those?

 

[Brew_G]

If they fermented out the starters, they were likely pretty healthy. Did you check attenuation on those?

That's what I figured, but thought I'd ask. I didn't check the gravity of this spent starter wort...but I usually do!

Funny thing is that I drank about a liter of the fermented starter because 1) I was curious to see how it tasted and 2) it was actually pretty good. It had a little diacetyl (which my Bell's starters usually have in spades) and was really clean and crisp with a little bit of carbonation. It was one of the more refreshing "beers" I've made!

I just made another starter with another jar of slurry that I put in the fridge at the same time. It's crashing in the fridge now, so when I decant, I'll check the gravity on it. I'm making these starters to build up my "yeast bank" - I split a few starters into two or three jelly jars for future use.

 

[Brew_G]

OK...having done some research on this, I *may* have found the culprit.

I mentioned how this yeast has served me well in the past. This is true; however, I haven't used it since I switched to a new fermenter - a 30L Speidel, compared to my 6.5-gallon glass carboy. Both of my last two batches were made with dry yeast (Notty and US-05).

Now...here's the kicker: I used to slosh the wort in my carboy pretty vigorously in order to aerate. With the Speidel, I just dump the whole contents of my kettle into it and figured that would suffice for aeration. Given that my last two batches hit their expected FGs, I figured I was doing it right. But that was with dry yeast, which it seems doesn't really need aeration.

So...given the fairly decent OG on this beer and the fact that I didn't aerate beyond a vigorous pour into the fermenter, it may very well be that the yeast crapped out a bit early due to a lack of sufficient oxygenation. Make sense?

 

[IslandLizard]

OK...having done some research on this, I *may* have found the culprit. [...]

So...given the fairly decent OG on this beer and the fact that I didn't aerate beyond a vigorous pour into the fermenter, it may very well be that the yeast crapped out a bit early due to a lack of sufficient oxygenation. Make sense?

Yeah, that's very possible. I already hinted at that earlier in the thread:

[...] Did you oxygenate well when pitching?

 

[Brew_G]

Yeah, that's very possible. I already hinted at that earlier in the thread:

Smarty pants...



Thanks for that, though. The lights were on but no one was home! I hadn't thought of the difference between dry and liquid yeast until I went back and looked through my notes and did some research online. Then it clicked - the lack of aeration makes perfect sense now when you consider my transfer process, the OG, and the use of liquid v dry yeast.

 

[Gavin C]

I foolishly didn't take a gravity reading before cold crashing. That's something I'd normally do, but I was lazy and didn't do it because I figured I'd be just fine letting it ferment out for 14 days.

I don't think you will have any bottle bombs. 2 weeks and all visible signs of fermentation gone, beer cleared/clearing things are finished. It's not going lower than that SG.

Trust your experience on this one. The safe rule mantra of repeated stable gravity readings is not bad advice but gets trumped by experience here. Sleep Easy @Brew_G

I think a culprit in BIAB with thin mashes and fine milling is slow dough-in. Conversion is so rapid that if you're too slow it may impact the FG. I have no good data or citations to add to this thinking. Possibly nonsense.

I've been step mashing starting at 130-144F for a first step and going up from there. Doughing in in under 1 minute. As apposed to striking high and coming down. I'm striking in the protein rest or beta amylase range and coming up either with direct firing the tun and stirring (important) or adding infusions.

It's very simple and under utilized with BIAB IMO. Step mashing can in theory add complexity to the mouthfeel and head retention of the beer. Again, not very well versed in the science so a pinch of salt warranted.

If you enjoy a bit of complexity, have the time and a good thermometer, this could be something to consider for a future brew.

This morning's mash. Protein rest, infusion to beta rest, decoction to alpha, direct heating to mash-out

 

[IslandLizard]

Smarty pants...



Thanks for that, though. The lights were on but no one was home! I hadn't thought of the difference between dry and liquid yeast until I went back and looked through my notes and did some research online. Then it clicked - the lack of aeration makes perfect sense now when you consider my transfer process, the OG, and the use of liquid v dry yeast.

Chances are it's a combination of things. Perhaps a not so viable yeast population didn't build as large of a starter as hoped for and a lack of oxygen stunted their growth rate after pitching. Maybe a sudden drop in temperature coaxed it into dormancy. If you only had taken the FG before racking and bottling...

We all get these flukes once in a while. I had a 5 gallon batch of 1.086 Old Ale with 2 packs of re-hydrated S-04 stall on me at 1.032! I never took a gravity reading during those 3 weeks until I was ready to rack, "knowing" it needed time to finish. My eyes were bulging while staring at the hydrometer sticking way up in the air...

I deduced it to a lack of oxygen at pitching and perhaps a few degrees drop at some point. Even holding it an extra week at 75-78°F didn't budge much but did knock 1-2 points off. Then we had to fill the club's barrel. Most members had their beer between 1.012 and 1.018.

 

[IslandLizard]

I don't think you will have any bottle bombs. 2 weeks and all visible signs of fermentation gone, beer cleared/clearing things are finished. It's not going lower than that SG.

Trust your experience on this one. The safe rule mantra of repeated stable gravity readings is not bad advice but gets trumped by experience here. Sleep Easy @Brew_G

Exactly! And your Brown Ale is still very drinkable, perhaps a bit sweeter than intended, but delicious otherwise. You could always add 1/4 shot of bourbon to a glass to jazz it up a bit.

I think a culprit in BIAB with thin mashes and fine milling is slow dough-in. Conversion is so rapid that if you're too slow it may impact the FG. I have no good data or citations to add to this thinking. Possibly nonsense.

I've been step mashing starting at 130-144F for a first step and going up from there. Doughing in in under 1 minute. As apposed to striking high and coming down. I'm striking in the protein rest or beta amylase range and coming up either with direct firing the tun and stirring (important) or adding infusions.

It's very simple and under utilized with BIAB IMO. Step mashing can in theory add complexity to the mouthfeel and head retention of the beer. Again, not very well versed in the science so a pinch of salt warranted.

If you enjoy a bit of complexity, have the time and a good thermometer, this could be something to consider for a future brew.

This morning's mash. Protein rest, infusion to beta rest, decoction to alpha, direct heating to mash-out

This is an excellent point, Gavin. I think it deserves it's own thread, so I hope you start one.

I use a cooler mash tun, which is truly impractical for step mashing unless you put a RIMS tube on it or use a HERMS coil, which only adds more equipment and tinkering. Maybe some day.

But instead, I've been thinking of step mashing in the boil kettle. It's easy to control heat input with the induction plate and good stirring is natural to me, keeps the arms strong. Then perform a real mash out @168°F for 10-15 minutes, dump the lot into the cooler which has a manifold, and use it just for lautering.

 

[Brew_G]

Thanks to both of you, @Gavin C and @IslandLizard. Definitely excellent advice and words to ease my worried mind!

Agreed that it'll probably be sweeter than expected, IL, but I'm OK with that. This is a beer that I'd already planned to supply to some friends and family, so I think the sweetness will work out just fine. It's hopped to a little over 40 IBUs with Willamette, Centennial, Cascade, and a little Columbus, so it may well be a blessing in disguise!

Gavin...on the surface, your process looks overwhelming, but I trust when you say it's not that hard. Wish we lived in the same area because I could learn a ton from watching you brew!

I'll be sure to post a follow up once I crack one of these puppies open. I love the fall drinking season!

 

[ejluttmann]

I use 60L speidels for 10-15 gallon batches and just recently started to use oxygen thru a stone to aerate. Prior to this I just sloshed it and could only get FG down to around 1.020, with oxygen I've now been getting it down to about 1.010.

 

[Brew_G]

I use 60L speidels for 10-15 gallon batches and just recently started to use oxygen thru a stone to aerate. Prior to this I just sloshed it and could only get FG down to around 1.020, with oxygen I've now been getting it down to about 1.010.

I'll give a few batches a whirl with the shake method since it did me just fine before I switched to my 30L. It's easy enough to button it up and have a really good shake session! If I find I need to make the move to O2 later on, I'll go ahead and have at it.

 

[Brew_G]

Update:

I chilled one of the browns for 24 hours and opened it this afternoon. Slightly carbed - enough to be acceptable, but definitely on the lower side - so I figured I'd drink it down. Quite good, though it has some of the typical buttery taste I get from young bottled beer fermented with Bell's yeast. Tons of mouthfeel and a higher level of sweetness (though not overwhelming).

As for the fears of over carbonation, I decided to open a second bottle and check the SG to make sure that no additional sugars had fermented out of the wort. After shaking it to hell and letting it rest at room temp, SG showed 1.021. Good stuff.

 

[Brew_G]

Just a follow up on where this beer is right now...

At 3.5 weeks post-bottling, it's got good carbonation and pretty head. Quite roasty, though with the expected sweetness of a beer that finished at 1.021. The carbonation is on the low side, which is what I was going for, so I think my concerns about packaging before fermentation was complete have been proven unfounded. Interestingly enough, though, this beer is quite dark, and with that roastiness it's almost like a sweet stout. No complaints though...it's a fine beer!

View attachment ImageUploadedByHome Brew1444437342.165880.jpgView attachment ImageUploadedByHome Brew1444437359.694906.jpg

 

[Gavin C]

Just a follow up on where this beer is right now...

At 3.5 weeks post-bottling, it's got good carbonation and pretty head. Quite roasty, though with the expected sweetness of a beer that finished at 1.021. The carbonation is on the low side, which is what I was going for, so I think my concerns about packaging before fermentation was complete have been proven unfounded. Interestingly enough, though, this beer is quite dark, and with that roastiness it's almost like a sweet stout. No complaints though...it's a fine beer!

View attachment 308564View attachment 308565

That looks really delicious. Good enough to drink. Thick creamy white head, Yum!

 

[Brew_G]

That looks really delicious. Good enough to drink. Thick creamy white head, Yum!

Gotta say...it's a really good beer. Not sure I'd want to drink more than two or three in one sitting, but it's quite enjoyable - chock full of flavor and smooth as silk. I'm looking forward to serving this, along with my pumpkin ale, to my buddies next weekend.

Yeah...that head *is* pretty. I thank the .5 lb of rolled oats for that. I'm shocked at how dark it is, though. Darker than any brown ale I've seen - porter/stout-like.

 

[Gavin C]

Gotta say...it's a really good beer. Not sure I'd want to drink more than two or three in one sitting, but it's quite enjoyable - chock full of flavor and smooth as silk. I'm looking forward to serving this, along with my pumpkin ale, to my buddies next weekend.

Yeah...that head *is* pretty. I thank the .5 lb of rolled oats for that. I'm shocked at how dark it is, though. Darker than any brown ale I've seen - porter/stout-like.

I think the 1/2 pound of chocolate got you the nice dark color.

It really sounds and looks like a great beer.

OG 1.066 and FG 1.021 A pretty big beer in my book, one that can easily handle that FG. What kind of IBU's did you have?

 

[Brew_G]

I think the 1/2 pound of chocolate got you the nice dark color.



It really sounds and looks like a great beer.



OG 1.066 and FG 1.021 A pretty big beer in my book, one that can easily handle that FG. What kind of IBU's did you have?

Thanks, Gavin. I appreciate the good words re: the recipe.

I used 0.5 lb chocolate in another brown last winter (my third or fourth batch) and I don't recall it being that dark. Perhaps the glass being so wide (that's about 18 oz of beer in there) is making it look darker than it would if it were in a glass that isn't so wide.

It's got about 41 IBUs, so it balances the sweetness pretty well. I wanted to get a little more hop character in the final product; it's there, but the sweetness and roast is a bit more prominent. Here's the hop schedule:

0.75 oz Columbus (12.9) - FWH
0.50 oz Centennial (9) - 10 min
0.50 oz Cascade (7.8) - 10 min
1.00 oz Willamette (4.9) - 10 min
0.67 oz Centennial - Flameout
0.50 oz Cascade - Flameout
0.75 oz Willamette - Flameout
0.50 oz Columbus - Flameout

 

[Gavin C]

Could well be the wide glass. The other thing to be aware of (you probably already are so apologies in advance if this is redundant info), is that not all chocolate malts are roasted/kilned to the same degree.

One malster's idea of chocolate malt is another's idea of a dark chocolate or pale chocolate. There is such variation in roasted malts. The lovibond rating is important to note carefully. Can be confusing to say the least.

From Briess


From Crisp


And Dingemans

 

[Brew_G]

Yup...definitely aware. I get nearly all my malts from my LHBS, including specialty malts from grab bins. The chocolate malt I've used is Briess at 350L.

Not a huge deal. Could simply be that my system and Brewers Friend didn't quite get the SRM right. Up next, I'm brewing what I'm calling a Winter Brown (bigger and with more hops), and I decided to add an ounce of Debittered Malt to it. If I didn't already have the grains all mixed I'd have left it out to see how the color turned out in that one. As it is, I suppose we'll see what happens!