Why is my ABV so low?

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dirtfang

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I just got done with a batch of American Brown ale. My OG was 1.040. I checked my FG about two weeks after being in the fermenter and it was 1.010. Four days later, I checked it again and it was 1.010, making my final gravity 1.010. That makes it roughly 4% ABV. Doesn't that seem low to you? The recipe said I should have ended up with an FG of 1.007. This is my second batch of brew. What is also a little strange is that my first batch was a steam beer and it ended up with the same final gravity. What is up?
 

Trox

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Have you calibrated your hydrometer, and also compensated for temp. I also think 4% is about where you should be for a beer with an OG of 1.040; if oyu post the ingredients it would help to figure out if you are missing a few points or are dead on. Recipes are notorious for being off a bit on things.
 

ilikeguns

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I just got done with a batch of American Brown ale. My OG was 1.040. I checked my FG about two weeks after being in the fermenter and it was 1.010. Four days later, I checked it again and it was 1.010, making my final gravity 1.010. That makes it roughly 4% ABV. Doesn't that seem low to you? The recipe said I should have ended up with an FG of 1.007. This is my second batch of brew. What is also a little strange is that my first batch was a steam beer and it ended up with the same final gravity. What is up?

I think the better question is why is your FG high and in reality, it's not that far off (your abv is only .3% off). Could be a lot of variables with the likely suspects being pitch rate, yeast viability and fermentation temperature. Can you give some more details about your fermentation?
 
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dirtfang

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No I have not calculated my hydrometer. I have only used it a couple of times and it is still pretty much brand-new. How do you calculate your hydrometer? My temperature has been pretty stable ranging between 62 and 66° in my carboy. Here is a picture of the recipe… ImageUploadedByHome Brew1388329794.381009.jpg
 

Trox

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Basically to calibrate your hydrometer you place it in the tube full of water and it should read 1.000 after the temp correction. If it isn't 1.000 then you will need to take those points into account when you take your readings; I know my hydrometer only reads 0.096 in tap water.

Edit: Also looking over the recipe I would say your FG is right where it needs to be, you will always have variations depending on the ingredients and how much the yeast feels like working. And a .003 difference is actually pretty good.
 

KeyWestBrewing

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I just got done with a batch of American Brown ale. My OG was 1.040. I checked my FG about two weeks after being in the fermenter and it was 1.010. Four days later, I checked it again and it was 1.010, making my final gravity 1.010. That makes it roughly 4% ABV. Doesn't that seem low to you? The recipe said I should have ended up with an FG of 1.007. This is my second batch of brew. What is also a little strange is that my first batch was a steam beer and it ended up with the same final gravity. What is up?

1.010 is a pretty common final gravity. Most of my beers finish up there or a touch higher. Even if it did finish up at 1.007 the difference really isn't much. The reason your beer is only 4abv is because you had an OG of 1.040 which isn't very high. If you did everything right you should still have a good drinking beer so in the end its nothing to worry about. But in the future if you want something stronger you need more base malt or extract to raise the gravity up. More base malt/extract = more fermentable sugar and more fermentable sugar = more alcohol.

Granted this is given that your grains have a good crush and your doing things properly to not lose efficiency.
 
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dirtfang

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I think the better question is why is your FG high and in reality, it's not that far off (your abv is only .3% off). Could be a lot of variables with the likely suspects being pitch rate, yeast viability and fermentation temperature. Can you give some more details about your fermentation?

What is pitch rate? I re-hydrated my yeast before pitching it. My whole fermentation process seemed to go according to plan. I had great airlock activity within about 6 to 8 hours and lasted For approximately 1.5 weeks. I had a great layer of Krausen and I never took off the airlock off of my carboy until two weeks had passed To check my final gravity. The brew was Nice and clear had a nice smell and a great taste.
 

reefriot

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Most average beers start with a OG of 1.052 so your a little low on the OG. 1.010 is a fine place for a beer to finish out. If you let it go too low it drys the beer out. Just beacuse the instructions say it should finish at 1.007 doesnt mean it always will. There are tons of factors to consider.
Did you under pitch your yeast?
What temp did it ferment at and was it a stable temp?
I dont see anything wrong with your OG and FG. How does it taste? If you like it then success. If you want a higher ABV add a bit more 2 row too your grainbill.
Remember this hobby is half science and half art! Some of my best beers where produced by accident:beer:
 

KeyWestBrewing

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Basically to calibrate your hydrometer you place it in the tube full of water and it should read 1.000 after the temp correction. If it isn't 1.000 then you will need to take those points into account when you take your readings; I know my hydrometer only reads 0.096 in tap water.

Edit: Also looking over the recipe I would say your FG is right where it needs to be, you will always have variations depending on the ingredients and how much the yeast feels like working. And a .003 difference is actually pretty good.

This is also a good point. Check your hydrometer so you know its calibrated. As well make sure not to take gravity readings if the temp is over 100f and that you adjust your readings for temperature. I promise doing all of this is way easier than it sounds.

Pitch rate is how much yeast you'll need in relation to the gravity of the wort. Use Mr.Malty.com it has everything you need.
 

B-Hoppy

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I think you're fine, but it all depends on the malts you use in your recipe as to how fermentable your wort will be. One other way to look at your situation is that you achieved 75% attenuation with your yeast. Some can attenuate to a much higher % and some lower, so you're at a good place (all things considered).

You could go with a more aggressive yeast next time for a lower final gravity (higher abv), but the final product will taste a little less filling. Keep on experimenting!
 
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dirtfang

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Thanks for all the info. As of right now I am using beer kits. It comes with one little packet of yeast. If I want to get more aggressive with my yeast pitch to raise my ABV ; do I just buy another yeast packet, Rehydrate it and pitch it along with the packet that comes in the kit? You don't think that would be detrimental to the overall taste of the beer?
 

KeyWestBrewing

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Thanks for all the info. As of right now I am using beer kits. It comes with one little packet of yeast. If I want to get more aggressive with my yeast pitch to raise my ABV ; do I just buy another yeast packet, Rehydrate it and pitch it along with the packet that comes in the kit? You don't think that would be detrimental to the overall taste of the beer?

Pretty much unless you use a liquid yeast. Then you'd make a starter to increase the amount of yeast cells you have. Pitching 2 packets won't have any negative influence on your beer either it will probably make it cleaner tasting. Under pitching is what can stress the yeast and cause off flavors leaving you with crappy beer. Really most homebrewers use a lower pitch count than commercial breweries do so I don't think you'll be overdoing it.
 

Yankeehillbrewer

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Thanks for all the info. As of right now I am using beer kits. It comes with one little packet of yeast. If I want to get more aggressive with my yeast pitch to raise my ABV ; do I just buy another yeast packet, Rehydrate it and pitch it along with the packet that comes in the kit? You don't think that would be detrimental to the overall taste of the beer?

It depends on what strain it is and how many grams are in the packet. But you are better off over pitching a little rather than under pitching. You can use the Pitch Rate Calculator on mrmalty.com to get an idea of how much you should pitch. But just increasing your yeast count doesn't mean you will raise your ABV. You have to have the fermentable sugar in there for the yeast to eat.
 

B-Hoppy

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But just increasing your yeast count doesn't mean you will raise your ABV. You have to have the fermentable sugar in there for the yeast to eat.

Being that you're just getting started, I would stick to this advice rather than trying to play around with too many variables at one time.

To take the above statement a little bit further: if you want a little more alcohol, just keep your present recipe as is and add some additional malt extract to your next batch. .5# to 1.0# of additional extract won't change the flavor of your final beer too much but will give you a little more alcohol. Try it and see what happens. Your yeast will most likely give you the same attenuation % if you keep the same fermentation conditions, but your gravities would look something like OG 1.046 and FG 1.011. Understand though, different styles have different gravity ranges to make them taste like what they're supposed to taste like. If you add TOO MUCH additional extract without adjusting your hopping rates, you'll get your extra alcohol but the beer may have a little more malty character than what you originally started out with.

For me, I tried reading and learning as much as I could when I first started (mid to late '80's), but I learned the most from my mistakes and also from deviating SLIGHTLY from proven recipies to see what I ended up with when "a little more of this" or "a little less of that" was thrown into the recipe.

It all takes time.
 

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