Why has my fermentation been stopping at 1.020?

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chungking

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I made an extract Big Ben pale ale kit from Midwest 3 weeks ago. Tried a few new things: rehydrated the dry yeast, incorporated a swamp cooler, and started using starsan.
Well, after almost 3 weeks in primary, just took a reading, and its at 1.020. Og was 1.050. This is the third batch in a row that stopped at that gravity. The swamp cooler has been in the mid to lower 60's the whole time. I can't think of anything I did wrong this time.

I had high hopes for this brew. Tried something basic, but its still messed up. My first batches hit the marks for both og and fg. Had no fermentation issues, and I was fermenting in ambient temps around 75, no swamp cooler...
 
From what I have read it is fairly common for extract brews to bottom out at or near 1.020. I don't know the reason and the couple that I did that were close to that turned out fine.

Generally I don't worry too much about FG unless it is a long way from predicted. I would worry about 1.020 if the predicted was near 1.005.
 
It's just really frustrating. You buy something expecting certain results, and you don't come close. Especially if you go the extra mile and make sure everything is perfect. I had better gravity readings my first time brewing with canned lme and letting it sit in 75+ temps.

This whole thing is nothing but stress and hasn't been that rewarding.

Sorry, just venting my frustrations.
 
Extract can cause yeast to poop out early, but not always. It could be an aeration problem. If you do not add enough oxygen to your wort when you pitch the yeast, it can have negative effects on your attenuation. Especially when you are working at the lower range for your yeast. Are you doing anything to aerate your beer? Even whisking the beer when it gets down to pitching temperature is better than nothing.

Hang in there. Sometimes you read these threads and walk away thinking that you are the only one making a bad batch here and there. I would bet that most of us have had our share of stinker batches. We all know the frustration. I'm far from all the way there after a year, but I am getting closer, and I sure know a lot more about commercial beers than I did a while ago. Its a craft, and takes some failures. Good luck figuring this one out.
 
I don't think it's an aeration problem. I poured about 2 gallons of distilled water in the fermenter, then poured in the wort, then stirred it up. Then filled it up to 5 gallons with more distilled water.

I just checked my hydrometer against some tap water in the mid 60's, it came out right around 1.002-1.003. So I think the hydrometer is ok.

I'm just waiting for that moment when I drink a homebrew and it tastes amazing, better then commercial beer. I have yet to hit that, with about 8 batches under my belt. It just seems like things are getting worse, not better...
 
This happened to me recently as well. I do mostly partial mash brews and I got some LME from a different supplier that only fermented down to around 1.020, on two seperate occasions. I found out from that supplier that there was a bad batch of LME in the supply chain that was fermented at too high a temperature. It seems reasonable that different homebrew supply retailers could be getting their extracts from the same sources, but I don't know.

Bottom line, the company did the right thing and replaced my extracts when I brought this to their attention. (That's why I'm not saying who it was...) But you should definitely let midwest know about this, and see what they can do for you.

Right now I am experimenting with adding amylase enzyme to the primaries on those two batches, and it seems to be working, as I have a good krausen going now. I just hope it doesn't go too low...
 
A few years ago when I started and was still doing extract brewing I had this problem in the beginning. I switched from Coopers yeast to SafAle-05 and Nottingham and the issue went away.
 
I used the safale 05 premium dry yeast. I used muntons regular dry yeast on previous kits that came with the true blew kits.

Just a bummer. Hopefully it will taste good. I'm trying to get the temp up to 70 to see if that helps, but I will probably bottle this weekend.
 
My first batch stuck at 1.020 too. Best as I know I did everything right enough it should have finished properly. So, to me, the only thing that really makes sense is the stuff I've seen about the LME.
 
Some extracts are only 55% fermentable according to a variety of studies including one detailed in "Designing Great Beers" so you actually did pretty good. Adjusting for the 3 gravity unit error you detected in your hyrometer an OG of 1.047 to the FG of 1.017 leaves you at 64% attenuation. If it tastes to cloying there are ways to fix it.
 
It's just really frustrating. You buy something expecting certain results, and you don't come close. Especially if you go the extra mile and make sure everything is perfect. I had better gravity readings my first time brewing with canned lme and letting it sit in 75+ temps.

This whole thing is nothing but stress and hasn't been that rewarding.

Sorry, just venting my frustrations.


Yeah its frustrating, but don't give up. We can read a ton about brewing, but its something completely different once you start doing it. Hang in there. BTW, I have only brewed all extract and have never had one hang higher than about 3 points above what I was aiming for.
 
Just as a thought; you could use a small amount of simple fermentables like dextrose to help bring your FG down.
 
If water is added with the dextrose it would lower the FG, but only to the effect that diluting the beer would. It might restart fermentation in some cases were the fermentation is truly stalled, but I don't think that is the case here.
 
Ah, I should have been more specific; I would use dextrose in the boil during the initial brewing of a new beer. Adding a simple fermentable should help give a lower FG. Just make sure to sub out some of the extract to keep you OG on target.

I wouldn't be adding it after the fact unless the recipe or style calls for it.
 
chungking said:
I made an extract Big Ben pale ale kit from Midwest 3 weeks ago. Tried a few new things: rehydrated the dry yeast, incorporated a swamp cooler, and started using starsan.
Well, after almost 3 weeks in primary, just took a reading, and its at 1.020. Og was 1.050. This is the third batch in a row that stopped at that gravity. The swamp cooler has been in the mid to lower 60's the whole time. I can't think of anything I did wrong this time.

I had high hopes for this brew. Tried something basic, but its still messed up. My first batches hit the marks for both og and fg. Had no fermentation issues, and I was fermenting in ambient temps around 75, no swamp cooler...

It sounds like you are using liquid malt extract. Is that correct? I see this when I use liquid malt extract too.

The fix is easy. Switch to using dried malt extract, or swap out some liquid malt extract for table sugar. Do not cringe at the idea. Malt extract is just a big jug of sugar anyway. So replace one sugar with another.

Maybe 1.25 lbs of liquid malt out, add 1 lbs cheap white table sugar. That will help a lot to finish lower, slightly lighter color and drier finish.
 
Maybe 1.25 lbs of liquid malt out, add 1 lbs cheap white table sugar. That will help a lot to finish lower, slightly lighter color and drier finish.

Well, that would work in the sense it might not stop at 1.020, but it might not have the best balance and flavor. It really depends on the rest of the recipe.

Many many of my extract batches stopped at 1.020, but the flavor was still great. Once it's carbed, it won't taste as sweet and should be really good anyway.
 
i bottled it yesterday. I brought the temp up to about 70, and the gravity came down a few points, then was stable the last two days. Finished around 1.016-1.017.

It tasted super sweet though, for a pale ale. Was hoping for a drier, hopper taste, but we'll see what happens as the bottles carb and age...
 
The gravity reading will change with temperature. The hydrometer reads lower or higher as the beer gets warmer or colder (respectively) than the hydrometer calibration temp. Not sure of the adjustment off the top of my head though.
 
. Not sure of the adjustment off the top of my head though.
within 10 degrees of ambient the reading is within 1 point, so as long as it cools to room temperature there is no need to go to the internet for a calculator or to look up a correction factor.
 
I wonder if it has something to do with Safeale 05 itself. I just racked the Brushfire brown recipe after 17 days in the primary. I keep my house at 68-69 degrees. My reading was 1.020. I've noticed this on my last few brews where I have used US-05. I brew all grain and have been hitting my OG targets. Both were 1.060. So, I ended up with 5.25% ABV vs 6.3%. I'm fine with that, but I do wonder why it finishes so short.
 
I highly recommend using a very attenuative yeast and supplementing 8-13% corn sugar (in place of extract) as a flameout addition. The 4-6% we typically see in all grain clones, like Pliny the Elder, is not enough to dry out an extract version.

Additionally, check what's going into your extract. I've had great success with Muntons Extra Light DME since the ppg/L ratings are extremely close to pure 2-row, meaning less fillers and crystal. There's no reason why you shouldn't have a drier beer than you're typically used to with 85% XL DME, 10% corn sugar, 5% crystal 20, and the appropriate amount of high attenuating yeast.
 
I wonder if it has something to do with Safeale 05 itself. I just racked the Brushfire brown recipe after 17 days in the primary. I keep my house at 68-69 degrees. My reading was 1.020. I've noticed this on my last few brews where I have used US-05. I brew all grain and have been hitting my OG targets. Both were 1.060. So, I ended up with 5.25% ABV vs 6.3%. I'm fine with that, but I do wonder why it finishes so short.

It's not US-05. My last batch was an extract kit and it finished right on target with 05; OG 1.054, FG 1.013.
 
I've brewed 2 batches, both Midwest, and they both had FG's of 1020. I'm new, I figured this was normal.
 
My bet is oxygen levels. I had this happen frequently, on extract or all-grain, then I started taking care of the O2 levels and all my problems went away in an instant.
 
My bet is oxygen levels. I had this happen frequently, on extract or all-grain, then I started taking care of the O2 levels and all my problems went away in an instant.

Ive been using http://www.austinhomebrew.com/product_info.php?cPath=178_34_458&products_id=10408 to aerate my wort before pitching. I do this for a solid 5 min and i have tight white foam almost coming out of my primary. I still hit that 1.020 some times. Even with the same kit and nothing done different.

Im thinking some extract is inconsistent. My best extract brews used Muntons or Briess brand. I know and have used other major brew supplies kits. Some say that they are from the former but just seem inconsistent. My two LHBS kits, one had Briess brand extract. The other uses Muntons. Online ive used kits from Midwest, Northern and Austin. They have been the ones that are hit and miss for me.
 
I've heard lots of theories...was going with the inconsistency of the extracts...but I think it's too consistently reported by new brewers and many of those are getting kits from places like MWS that moves lots of stuff.

Thinking back, I boiled the crap out of my first batch because most new brewers know you have to have a seething cauldron, and I'm wondering if that didn't somehow alter the sugars into something less fermentable. Also, I used just the standard yeast provided with the kit, while probably OK yeast, it was only 1/2 the recommended pitch rate for a 5gal batch according to the pitch rate calculators (I didn't know about at the time).
 
I've heard lots of theories...was going with the inconsistency of the extracts...but I think it's too consistently reported by new brewers and many of those are getting kits from places like MWS that moves lots of stuff.

Thinking back, I boiled the crap out of my first batch because most new brewers know you have to have a seething cauldron, and I'm wondering if that didn't somehow alter the sugars into something less fermentable. Also, I used just the standard yeast provided with the kit, while probably OK yeast, it was only 1/2 the recommended pitch rate for a 5gal batch according to the pitch rate calculators (I didn't know about at the time).

I did this with my last batch. I always dialed back my temp just to boiling. This time i cranked it up. Thinking maybe i want breaking down the extract enough. I even put all in instead of late addition. This batch isn't fermenting as hard. Its something in the process or in the ingredients.
 
Thinking back, I boiled the crap out of my first batch because most new brewers know you have to have a seething cauldron, and I'm wondering if that didn't somehow alter the sugars into something less fermentable.

I've had the same problem when I had a "seething cauldron" boil in my small (16 qt) kettle and noticed the OG go up a few points. I found I could get it down another couple of points with a full boil(if you can find a big enough pot) to try and prevent some scorching while still getting good a hot break and hop utilization.
 
i heard that a little while back safale had a bad batch of us05 that could be the problem, try another yeast

I certainly can't discount that possibility across the board, but my US-05 extract batch worked fine. The Munton's batch did not.

Problem is, there was more than one variable changed between the cases so it's near impossible to pin it down exactly.
 
Doing some more research on this, I'm wondering if my water ratio is playing a part in this. I mash at 1.25 qts/lb, which is considered a stiffer mash. Research tends to show that a mash of this ratio will result in less fermentable sugars and, therefore, a sweeter/maltier beer. I seem to be hitting 1.060 OG with each all grain batch and it tends to end around 1.020 FG. Any thoughts from the all grain crowd?
 
IME mash thickness doesn't change fermentability much, and nither does the amount of crystal. The biggest driver is mash temperature. To a lesser degree mash time will change fermentability. Check your thermometer in boiling water to get a ball park idea of how far off it may be at mash temperatures.

Here is some excellent research on these factors by Kai:
http://braukaiser.com/wiki/index.ph...ity_and_efficiency_in_single_infusion_mashing

And here is some digested information on thermometers:
http://woodlandbrew.blogspot.com/2012/10/mash-temperature-and-thermometers.html
 

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