Low ABV ... whyyyyy

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ophillium

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Hey folks, I'm hoping for some insight into this problem my partner and I have been having - the gist of it is that after 4 batches we can't seem to break the 3% ABV ceiling.

We're brewing in a bag, fermenting (low) around 17 - 20 C, and racking after approx 10 days for approx 2 weeks (depending on the recipe).

Here are our results:

Guinness Clone 1
Target: 1.044
Starter: No
OG: 1.044
SG: 1.025
ABV: 2.5%

Guinness Clone 2
Target: 1.044
Starter: No
OG: 1.040
SG: 1.018
ABV: 2.9%

Guinness Clone 3
Target: 1.044
Starter: Yes
OG: 1.034
SG: 1.012
ABV: 2.9%

ESB
Target: 1.040
Starter: No
OG: 1.032
SG: 1.018
ABV: 1.85

My guess is that our fermentation temp is too low - which is hard to change because we're in a basement.

Any thoughts?
Also, is the down-side of a low ABV just that it won't keep for long?
So many questions :drunk:
 
Remember that the alcohol comes from yeast "eating" the sugars, and producing the alcohol and CO2. What that means is that in order to get a higher ABV, you need more sugars.

The Guiness clone #1 had a too-high FG, but the others were in range so if you want more ABV, simply start with more sugar at the beginning.

A good rule of thumb to estimate ABV is (OG-FG) x 131= ABV (approx).

So, for a 1.044 beer, with a FG of 1.018, that means an ABV of 3.4%. If you're using extract, the only way you can miss your OG is if you don't add the correct amount of water. The sugars are in there, and don't go away. If your volume isn't correct, and you have "about" 5 gallons, that could be why you're missing your OG. I'd recommend measuring your volumes because often the markings on buckets and fermenters are not correct.

In other words, if you want a higher ABV, start with a beer recipe with a higher OG.

There is nothing wrong with a lower ABV beer. Many of us do that on purpose, so we can drink several beers without being unable to drive or play with our kids. Most of my beers are "session" beers, so I can enjoy them and not be affected. If you want a higher ABV, maybe choose a recipe that has a higher ABV than the ones you're using.
 
Are those hydrometer readings or refractometer?

Don't rack after 10 days, secondaries are hardly necessary for those ales, just leave in primary and raise temps a few degrees toward the end to help finish them up and condition the beer. You're literally pulling the yeast rug from underneath them, probably before they're done.

What yeast are you using, how much, and how fresh is it? Making starters with liquid yeast is important. So is oxygenation when pitching.
 
From here it looks like you need a different recipe, maybe a different mash temp if your are using grain and perhaps a different yeast that will ferment down below where you are ending the first four brews.
 
My last biab went from 68% to 79% efficiency with the implementation of recirculating during the mash. If you biab, try a finer crush!
 
I'm gonna guess you're doing all-grain? When I started I had same problem and found out that my sparging technique was all wrong. I fixed that and haven't had a problem since.

But we're not gonna be able to help without knowing more about your process and setup
 
How much grain are you using to make how much beer? Those are mostly fairly low OG so looks like the problem is on the mashing side rather than on the fermenting side.
 
Thanks so much to everyone for chiming in. Here are some specific responses:

Powhatan: How well are you oxygenating the wort prior to pitching?
- Good question. I'm pouring straight from my brew pot into my carboy and giving it a really good shake. Should I be doing more than that?

Yooper: In other words, if you want a higher ABV, start with a beer recipe with a higher OG.
- My concern really is that I'm not hitting my desired ABV, I suppose. For the most part I'm working with recipes that hover around 4%, but the final product is coming in below 3%.

MindenMan: Is it possible your thermometer is wrong and your mash temperature is too high?
- That's possible. Is lower attenuation (which is what I think I'm looking at here) caused by a higher-than-desired mash temperature? Should I stir the wort a ton before mashing and chilling?

Skiffy: Yea we need some more information on your brewing process. The fermentation temperature is fine.
- Great to know, thank you. I've been thinking about the fermentation temperature a lot. More on my process below.

IslandLizard: Are those hydrometer readings or refractometer?
Don't rack after 10 days, secondaries are hardly necessary for those ales, just leave in primary and raise temps a few degrees toward the end to help finish them up and condition the beer
What yeast are you using, how much, and how fresh is it? Making starters with liquid yeast is important. So is oxygenation when pitching.
- Hydrometer.
- Good call. I'm using Wyeast liquid cultures, ranging from the not-so-fresh to the very-fresh-indeed. Made a starter for batch 3 of the Guinness clone; the lower-than-desired OG didn't help anything there though.

cannman: If you biab, try a finer crush!
- Excellent advice, thank you. I am brewing in a bag.

ElJefeBrews: I'm gonna guess you're doing all-grain?
But we're not gonna be able to help without knowing more about your process and setup
- I'm brewing all-grain recipes in a bag, making 4 gallon batches out of a 7 gallon brewpot. What else can I tell you that would be helpful?
 
more questions :D
What is your water temperature before you lower in the grain and what is your desired/measured mash temperature.

How much water do you mash how much grain in? what kind of grain?

Low OG is caused by not enough grains or a bad mash/crush.
High FG is either too short fermentation or too hot mash.
 
ophillium said:
@IslandLizard - Good call. I'm using Wyeast liquid cultures, ranging from the not-so-fresh to the very-fresh-indeed. Made a starter for batch 3 of the Guinness clone; the lower-than-desired OG didn't help anything there though.
Click to expand...

Most brewers don't use % alcohol as a guide to beer being finished. It is the Final Gravity (FG) that's the target.
An FG of 1.018 from 1.040 OG (Guinness #2) is lousy and even worse from 1.032 (ESB). Using a yeast's attenuation capability, say 75%, your 1.040 OG should realistically attenuate to 1.010. It could end up 2 points higher or lower depending on many factors, even 4, but 8-10 points higher means something is in disarray. Mashing too hot creates a lot of unfermentables, as does larger amounts of crystal malt and Carapils.

The other part to look at is the freshness of the malt, mainly how it was stored. Stored too hot and/or long, long times will denature enzymes, rendering them incapable to convert the starches to the levels we want and expect, ending in a low mash efficiency, and not being able to produce a very fermentable wort. Remember, beta-amylase nibbles off the ends of the starch chains and the dextrins produced by alpha-amylase.

Lots of good advice was already given where to find the culprits. Attenuation is fermentation related, and has nothing to do with crush, although that crush itself is surely responsible for low mash efficiency, which you should look at too. Crush finer! Gap settings of 1.030" or even tighter are normal for BIAB. None of the grain bits should be larger than 1/8", most should be way finer with a bit of flour being acceptable.

Good yeast starters are the key to healthy fermentations. Even older yeast can be brought back to life:

For example, a few weeks ago I built up a starter from some yeast I had saved from a starter I had made last year around the same time. It had been stored in the fridge since, but had become quite brown. Hmm? After 3 days on the stir plate I had a good light-tan starter yielding a decent layer of yeast after cold crashing. On brew day I ended up questioning the actual cell count, when weighing the slurry after decanting. I decided to add some fresh wort from the beer I had just brewed and put the flask back on the stir plate. About 8 hours later I pitched all of this now highly active starter, without decanting of course, and whisked 1 minute for oxygenation. Lift off was within 4 hours... making awesome beer that attenuated 2 points below target, and 6 points below last year's batch.​
 
ophillium said:
Hey folks, I'm hoping for some insight into this problem my partner and I have been having - the gist of it is that after 4 batches we can't seem to break the 3% ABV ceiling.

We're brewing in a bag, fermenting (low) around 17 - 20 C, and racking after approx 10 days for approx 2 weeks (depending on the recipe).

Here are our results:

Guinness Clone 1
Target: 1.044
Starter: No
OG: 1.044
SG: 1.025
ABV: 2.5%

Guinness Clone 2
Target: 1.044
Starter: No
OG: 1.040
SG: 1.018
ABV: 2.9%

Guinness Clone 3
Target: 1.044
Starter: Yes
OG: 1.034
SG: 1.012
ABV: 2.9%

ESB
Target: 1.040
Starter: No
OG: 1.032
SG: 1.018
ABV: 1.85

My guess is that our fermentation temp is too low - which is hard to change because we're in a basement.

Any thoughts?
Also, is the down-side of a low ABV just that it won't keep for long?
So many questions :drunk:
Click to expand...

Your fermentation temperature is good for the beginning but you might persuade the yeast to eat a little more if you warm the beer up a bit at the end of the fast part of the ferment. I like to leave my beers cool for about a week before I warm them.

You have the advantage of the cool basement to ferment in so you don't need an expensive refrigeration system. Warming the beer is so much cheaper than cooling it. Set your fermenter in a tub and when the fermentation slows down, add some warm water into the tub so it surrounds the fermenter. You can choose the temperature of the water to warm the beer to the temperature you like. I like to bring my beer's temperature from about 17C to about 22C and keep it there for another 2 weeks although just a couple days would probably be plenty to get the beer done.
 
Like others have said, that fermentation temperature is great for almost all strains of yeast; by staying on the lower side of the temperature range, you're much less likely to encounter things like fusel alcohols that arise when your primary fermentation is too hot. However, on the flip side, fermenting on the lower end of the range also means fermentation will take longer. This seems especially true for your first batch, where you only got 43% attenuation and then racked to secondary. Like most people on HBT will make clear, secondary fermenters are rarely necessary these days- they're simply a holdover from a time when brewer's yeast was much less hearty and prone to creating off flavors in beer if left in contact for too long. By racking after only 10 days, you're probably transferring the beer off the yeast cake before it's finished fermenting, which means less sugar being converted into alcohol, which is the very issue you're bringing up; even your best attenuation is only 65%. Skip the secondary and let the beer stay in the primary for a few extra weeks, and don't bottle until your FG is consistent for a few days apart.

Also, it seems like your mash efficiency is a bit low compared to your projected OGs. There's a few different things that contribute to a low mash efficiency- grain crack size, not mashing for long enough, too cold/hot mash. Playing with the crack size really helped me in the past when I had issues, and using an iodine test to make sure conversion has happened before sparging is a quick and easy way to help improve efficiency as well. If you get your actual OGs closer to your target OGs, and get 75% attenuation from your yeast (which is average for most yeast), you should see something closer to 4.3% ABV in your Guinness clone, which is still a pretty sessionable beer.

Good luck!
 
Why is this thread missing the recipe? Or am I completely missing it? That would answer like... all the questions.

Mash temp, grain, ferment temp. You know, that stuff.
 
I agree. I strongly suspect the answer is some combination of: Too many unfermentables in the recipe and too high a mash temp (either deliberately or accidentally due to a faulty thermometer).
 
After reviewing everything, I'm going to go with -- make sure you thermometer and hydrometer/refractometer are accurate and calibrated.

If you are using a cheap dial thermometer you are almost guaranteed to be mashing at the wrong temps. They are often off by 20+ degrees after the first couple uses. I would invest in this guy (Less than $20 and have never done me wrong) and provides a temp reading quickly, they will also last a very long time if you don't drop in boiling wort (which I have done).
http://www.thermoworks.com/products/low_cost/rt600b.html

You also need to start paying attention to your efficiency. If your target OG is 1.040 and you hit 1.035 and assuming you mashed at an appropriate temperature and are keeping your volumes consistent you need to use more grain or mill with a finer crush (most stores won't let you adjust the mill, so use more grain). Also, BIAB'ers are going to yell at me, but one of the disadvantages to BIAB is lower efficiency, so again, you might just need to use more grain. But by looking at your OG and FG, I think you have to get your temps dialed in, then once that is good, start looking at efficiency. If you had good starch conversion, on a 1.040 beer you should be landing lower than 1.010 is most cases.
 
RmikeVT said:
[...] Also, BIAB'ers are going to yell at me, but one of the disadvantages to BIAB is lower efficiency, [...]
Click to expand...

I don't do BIAB but I'm still going to yell at you ;)

Actually most BIAB have higher efficiency than conventional mashing systems because they can crush much finer, almost to flour. 85-90% is not unheard of. Now if the bag just gets pulled and drained into a bucket some high gravity wort may stay behind and you'll be taking a hit on efficiency. However, a good squeeze followed by some sparging, simply by pouring hot water over the bag, and a good squeeze once more, can add another 5-10% to your efficiency.
 
Recalibrate your thermometer.. Mine was off by 6 degrees from the store

Screws everything up

Also, check your gravity pre-boil and adjust to reach your target OG
 
IslandLizard said:
I don't do BIAB but I'm still going to yell at you ;)

Actually most BIAB have higher efficiency than conventional mashing systems because they can crush much finer, almost to flour. 85-90% is not unheard of. Now if the bag just gets pulled and drained into a bucket some high gravity wort may stay behind and you'll be taking a hit on efficiency. However, a good squeeze followed by some sparging, simply by pouring hot water over the bag, and a good squeeze once more, can add another 5-10% to your efficiency.
Click to expand...

Hmmm, I usually just squeeze (like it owes me a million dollars) after sparging, should probably squeeze after the mash as well.

Think doing a dunk sparge with BIAB is pretty easy. Usually dump a bunch of hot water into an empty fermenter and then let the bag sit in the water for a bit and stir the gain around every so often then pull out and squeeze for all I'm worth. So far so good. Still pretty new at this but my efficiency has been rising with each batch as I figure stuff out.
 
RmikeVT said:
Also, BIAB'ers are going to yell at me, but one of the disadvantages to BIAB is lower efficiency, so again, .
Click to expand...

I won't yell either but whisper gently, "this is simply not the case"

If you consider consistent brewhouse efficiencies in the 80% range, low well I suppose we have differing definitions of low efficiencies and I will concede the point.

The nature of the lautering method will have minimal impact on brewhouse efficiency assuming the lautering process is done correctly. BIAB is nothing more than a lautering process. Adding anymore importance to it than that is pointless.

Bumping this to a more complex type of process the statement is analogous to someone saying, RIMS systems will always scorch the wort a bit. Not if your doing it right. (Disclaimer I have no experience with RIMS, I know this is often cited by detractors, I'm thinking it's a problem easily avoided.)

BIAB should have nothing whatsoever to do with the OP's results if they are doing it correctly. I have seen posts where folks state they are BIABing and are trying to mash in the same manner as one would steep grains. That aint gonna work. The minimally provided info all point's to recipe and mash profiles (planned or unplanned via bad thermometer). The type of manifold/mesh bag/bazooka screen/false bottom is irrelevant.
 
Bosh said:
Hmmm, I usually just squeeze (like it owes me a million dollars) after sparging, should probably squeeze after the mash as well.
Click to expand...

I do BIAB for my smaller, 1 gallon batches, and the "squeezing the grain bag" part has so far vexed me. That thing is hot, wet, and sticky! How do you squeeze it without burning your hands?
 
kombat said:
I do BIAB for my smaller, 1 gallon batches, and the "squeezing the grain bag" part has so far vexed me. That thing is hot, wet, and sticky! How do you squeeze it without burning your hands?
Click to expand...

I do it one of two ways, depending on how drunk I am at that point.

Not very drunk - I put the bag on a veggie tray for the grill (it has holes and is very sturdy) over a bucket, then I take a pot lid and press down on it with all my weight. I rotate the bag a few times, and keep pressing until nothing comes out.

Drunk - Hold bag with one hand over pot, squeeze in various places on the bag until you start to feel your hand burning, then quickly remove it, curse and repeat as necessary.

I usually end up doing the latter.
 
kombat said:
I do BIAB for my smaller, 1 gallon batches, and the "squeezing the grain bag" part has so far vexed me. That thing is hot, wet, and sticky! How do you squeeze it without burning your hands?
Click to expand...

Wilserbrewer claims that just hanging the bag of grains above the pot and letting it drip gets about the same amount of wort out of it and takes no squeezing, just time and a way to hang it. YMMV
 
What I've been doing is moving the bag over into a colander in a big bowl and letting it drip. By the time the rest of the wort reaches a boil, I pour whatever excess has drained into the pot with the rest, but it's seldom more than a few ounces.
 
Psylocide said:
I do it one of two ways, depending on how drunk I am at that point.

Not very drunk - I put the bag on a veggie tray for the grill (it has holes and is very sturdy) over a bucket, then I take a pot lid and press down on it with all my weight. I rotate the bag a few times, and keep pressing until nothing comes out.

Drunk - Hold bag with one hand over pot, squeeze in various places on the bag until you start to feel your hand burning, then quickly remove it, curse and repeat as necessary.

I usually end up doing the latter.
Click to expand...

No, you pour a small glass of cold water over it to "sparge" and drunkenly convince yourself the entire thing is MUCH cooler now and burn your hands again. Rinse and repeat, literally
 
Bosh said:
Hmmm, I usually just squeeze (like it owes me a million dollars) after sparging, should probably squeeze after the mash as well.

Think doing a dunk sparge with BIAB is pretty easy. Usually dump a bunch of hot water into an empty fermenter and then let the bag sit in the water for a bit and stir the gain around every so often then pull out and squeeze for all I'm worth. So far so good. Still pretty new at this but my efficiency has been rising with each batch as I figure stuff out.
Click to expand...

Yes, squeezing before sparging will recover more sugar, since you are squeezing out high gravity wort vs. low gravity wort, if squeezing after sparging. Then when you sparge, the sparged wort will be lower gravity, and whatever wort is left in the grain will contain less sugar. The less sugar you leave behind, the higher your efficiency. Efficiency is all about sugar collected vs sugar losses.

Your sparge process looks fine, and aggressive stirring at the beginning is most effective.

I'll chime in with the others on getting a good digital thermometer, and checking the calibration before using it. You appear to have mash fermentability issues, which are often due to mashing at temps that are too high (thermometer reads too low.)

Brew on :mug:
 
kombat said:
I do BIAB for my smaller, 1 gallon batches, and the "squeezing the grain bag" part has so far vexed me. That thing is hot, wet, and sticky! How do you squeeze it without burning your hands?
Click to expand...

Usually grabbing the top end of the bag and shoving the rest of it against the wall of a bottling bucket to get as much as I can out and then when it's cooled down a bit just squeezing it with by bare hands while being annoyed by the heat. Then add what I can squeeze out bit by bit to the pots as they start to heat up to boil the hops.
 
For BIAB I mash with 2 gallons less than the total water I need. I'll pull the bag out and set it on a heavy rack and squeeze as much out with a pot lid that I can. Then I put the bag in a home depot bucket and dump 2 gallons of room temperature water in and stir it for a few minutes then let it sit for a total of 10 minutes. At this point the bag is cool enough to squeeze the hell out of it with your bare hands. The extra wort makes a difference.


Yes, It's alright to sparge with cool water. My efficiency has gone up to 80% on some batches. This is with a LHBS single pass grain crush.
 
Subdivisions said:
For BIAB I mash with 2 gallons less than the total water I need. I'll pull the bag out and set it on a heavy rack and squeeze as much out with a pot lid that I can. Then I put the bag in a home depot bucket and dump 2 gallons of room temperature water in and stir it for a few minutes then let it sit for a total of 10 minutes. At this point the bag is cool enough to squeeze the hell out of it with your bare hands. The extra wort makes a difference.


Yes, It's alright to sparge with cool water. My efficiency has gone up to 80% on some batches. This is with a LHBS single pass grain crush.
Click to expand...

Yeah considering sparging in cool water as well just to save my poor hands.
 
Another vote here for mash temperature. I was high by about 3°C and attenuation dropped from 80% to under 70%. Yours is all over the place. Check your thermometer reads around 100°C at boiling.
 
Temperature and a finer grind for my grain seem to be the most likely suspects, so I'll start there. I'll also leave each batch in the primary longer just to be sure. Oh, patience. So hard to find sometimes, yet the rewards are so great.

Thanks to everyone for such thorough responses :mug:
 
Subdivisions said:
Do it. There's absolutely no difference in efficiency.
Click to expand...

Only problem is my pathetic electric stove takes FOREVER to get up to boil (even splitting the wort into two pots and putting each on one burner). Takes long enough to heat up hot sparge water to boiling, I shudder to think of how long it would take with cold sparge water.

So. Swearing at damn grain bag burning my hands vs. brew day taking up longer and four year old waking up and grabbing stuff before I'm done, hmmm....
 

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