I brewed a chocolate porter two weeks ago and it's stuck. OG before pitching was 1.045 and it is at 1.027 (for a week now). I'm pretty sure I hit all my temps. I did use a lot of coco powder (13 oz.) in the mash tun, but not sure why that would have stopped the yeast. Room temp is 55-60, but I have a brew belt on it and the times I've checked the temp of the beer it is 70-73. I tried to get it going again with some corn sugar and yeast nutrient, but nothing. So...my idea was to: (1) re-yeast it with a yeast starter I made today; (2) re-yeast it with 1/2 the starter and use the other half for a red ale I planned to make this week; (3) make the red ale this week and rack the porter onto part of the ale's yeast cake in a few weeks; or (4) make an imperial stout in a few weeks (when I can get the grain) and blend the porter and stout to hopefully get something around 5-6% abv. Ideas?
Ideas for low fg beer
- Thread starter dharvey
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Let's break this down into two parts -- the cause and the solution.
The cause:
There's several possibilities, but we need more information. How much yeast did you pitch? How fresh was it? You indicate you have a starter going today, so I'm going to guess you used a starter for this beer. How big was the starter?
Assuming you did use a starter of an appropriate size, then you need to consider some other causes. You've already ruled out temperature issues, so next is the possibility that you don't have a stuck mash. It may be that your fermentation is finished. Can you post your recipe and process? If you used a high proportion of crystal malts and/or mashed at a high temperature (over 156-158 F), it may be you had a relatively small percentage of fermentable sugars.
Some things you can try:
If you don't have an excessively high percentage of unfermentable sugars, you can add more yeast, as you suggest. This is probably your best option. You don't indicate how big the starter you made today is, but I'd probably pitch the whole thing in there and make a fresh starter for your red ale. Your option number (3) is a possibility. You might even find that by then your FG was dropped to an acceptable level.
Blending the beer is a good option, as well. But I don't know that I would make an RIS and blend it. Instead, I'd probably brew something that would likely finish very dry (consider something like a Cascadian ale). This way, all those residual sugars in your chocolate porter will get spread out across a larger batch, and should give you a fairly tasty porter/stout.
The cause:
There's several possibilities, but we need more information. How much yeast did you pitch? How fresh was it? You indicate you have a starter going today, so I'm going to guess you used a starter for this beer. How big was the starter?
Assuming you did use a starter of an appropriate size, then you need to consider some other causes. You've already ruled out temperature issues, so next is the possibility that you don't have a stuck mash. It may be that your fermentation is finished. Can you post your recipe and process? If you used a high proportion of crystal malts and/or mashed at a high temperature (over 156-158 F), it may be you had a relatively small percentage of fermentable sugars.
Some things you can try:
If you don't have an excessively high percentage of unfermentable sugars, you can add more yeast, as you suggest. This is probably your best option. You don't indicate how big the starter you made today is, but I'd probably pitch the whole thing in there and make a fresh starter for your red ale. Your option number (3) is a possibility. You might even find that by then your FG was dropped to an acceptable level.
Blending the beer is a good option, as well. But I don't know that I would make an RIS and blend it. Instead, I'd probably brew something that would likely finish very dry (consider something like a Cascadian ale). This way, all those residual sugars in your chocolate porter will get spread out across a larger batch, and should give you a fairly tasty porter/stout.
Option 5) add some amylase enzyme to break down long chain sugars to more fermentable ones (assuming your problem is to many unfermentables from either recipe or mash temp).
As said posting your recipe might get you some more help.
As said posting your recipe might get you some more help.
I actually didn't use a starter. i used a wyeast pack. the recipe was: 5 lbs maris, 3 lbs brown malt, 2 lbs caramel malt, plus the coco powder. i continuously hopped 1 oz of goldings. i mashed at 170 and kept it at 155-149 for 1 hr in my cooler mash tun. i got about 4 gallons out and then i sparged at 175 and kept it at 165 for 20 minutes and got 2.25 gallons. i boiled the 6.25 gallons of wort for 60 minutes. with an ice bath i was able to pitch 55 minutes later.
the starer i made today is 2L.
thanks for the ideas and help!
the starer i made today is 2L.
thanks for the ideas and help!
hopbrad
Well-Known Member
amalyse will work if u get the beta enzyme, heat stops the enzyme so it wont stop and it will break down all the long chain dextrins until it goes to 1.000, it also works very slow at lower/non-mash temps. if you bottle too early, you may get bottle bombs, if you keg, then not a big deal, keg when you get to your target gravity.
pitching more yeast would be my first try. something like belle saison that is known to be a great attenuator would bring it down and shouldnt give you much, if any, belgian character.
pitching more yeast would be my first try. something like belle saison that is known to be a great attenuator would bring it down and shouldnt give you much, if any, belgian character.
20% crystal/caramel malt would make a ton of unfermentables, but the range of "155-149(?)" is troublesome. A mash temp of 155 would make a very high FG beer, with lots of dextrines, and a heavy body.. A mash temp of 149 would favor a very thin body, with lots of fermentable sugars.
So which is it? Did you mash at 155? Or did you mash at 149? If you mashed at 155, how long did it stay there? A 155 degree mash would convert in 20 minutes, so if you started at 155 and stayed there for any period of time, I'd call that a 155 degree mash.
no reason at all to hold a batch sparge at any length of time, but that isn't the cause of the high FG. Next time, stir in your sparge water. Stir some more, stir again, and then vorlauf and drain. It doesn't take more than about 5 minutes.
WI_Wino
Well-Known Member
How are you measuring gravity? Hydrometer or refractometer?
i was in my uninsulated barn and the temp was 20s, so my tun didn't hold as well as it normally would. I started at 155 and after 20 min it had gone down to 153 and by the end it was at 149, so about a 2 degree drop every 20 min. good to know about the sparge...thanks!
WI_Wino
Well-Known Member
Refractometers read higher a gravity than what it really is after fermentation has started. Use a hydrometer and I bet your gravity is more where you expect it to be.
Oh, that's why! Run and get a hydrometer reading.
Refractometers read a sugar (sucrose) solution via a light index. Alcohol skews that, so the reading is not accurate once alcohol is in the mixture.
There are some online calculators that help guess the FG if you input the wort correction factor and the OG, so that might be helpful as well.
ugh, i feel like an idiot. i don't know how i didn't know that. i've used it for my last three beers and all were a bit off, but this one by a lot. it looks like with the online calculator that 10 brix is about 1.04 and 6.5 is 1.026, which gives about 3.1% ABV. I'm still about 1% lower. Good news is I already added a tsp of the amylase. But thanks, this explains why my other two were off!
Those numbers still don't add up correctly, because of the alcohol and the wort correction factor.
Do you have a hydrometer? That's really needed for FG readings.
Beersmith has a tool that corrects for this. I plugged your SG of 1.045 and a brix reading of 6.5 into that. It gives a corrected gravity of 1.014 and an ABV of 4.09%.
While that is much better, it still might finish a bit sweet. Your amylase should help. If you brew this again, you may want to cut back on the crystal malts.
hopbrad
Well-Known Member
wait a few weeks to bottle since you added the amylase to ensure gravity doesn't keep dropping to avoid bottle bombs.
1.014 woulda been pretty much on point for a chocolate porter.
I agree with everyone else, cut the crystal next time and get a hydrometer. refractometers are amazing for brew day, especially with all grain but hydrometers are best/easiest to calculate FG.
1.014 woulda been pretty much on point for a chocolate porter.
I agree with everyone else, cut the crystal next time and get a hydrometer. refractometers are amazing for brew day, especially with all grain but hydrometers are best/easiest to calculate FG.
Let us know how you make out. You may find that you have stumbled into a "lite" beer that actually tastes good!
I once made a quadruple-chocolate Porter (baker's unsweetened, cocoa, semi-sweet, and Toll house morsels) for a young lady friend of ours and it seemed to be stuck, so I took a pound of Panela (like Jaggery, Pilloncillo i.e. really raw sugar from South America) and boiled it in a couple of cups of water, let it cool to the same temp as the fermenter, added yeast and gave it a couple of hours to get started, and poured it into the fermenter - it took off and went for another week - came out great! NOTE: I always add my powdered cocoa during the dry-hop in secondary.
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