Brew ABV too low

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Jake_Robbo

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I have made 5 brews now and my strongest has come out at about 3.6% according to my gravity readings. Some were as low as 2.8. After drinking 5 750mL beers I don’t have the slightest buzz so I know it’s not just that I am reading wrong. Any idea what could be happening?
 
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Well without a recipe it’s all speculation. But if your beers are consistently low gravity, you could either double up your recipes and make two batches into one to increase the gravity. Or reduce the amount of water used per batch to increase the gravity to give you a higher abv brew with slightly less volume.
 
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Jake_Robbo

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Well without a recipe it’s all speculation. But if your beers are consistently low gravity, you could either double up your recipes and make two batches into one to increase the gravity. Or reduce the amount of water used per batch to increase the gravity to give you a higher abv brew with slightly less volume.
I have been using Coopers Irish stout cans and a creamy stout mix that the brew shop make. They have some dextrose and dark malt in them. Although I made a Morgan’s cerveza with a Morgan’s full body dextrose pack and still got around 2.8%.
 

schmurf

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Aren't the coopers extracts low in alcohol from start, and you're supposed to add extra DME or sugar to up the ABV?
 

Kickass

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How many kg’s or pounds of extract are you using?

What’s your wort volume?

How are you measuring your OG and FG?
 

DannyBoy270

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What are you getting for your OG reading before you pitch your yeast?
 

myndflyte

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You using a refractometer to take final gravity readings? Because alcohol will throw off the refractometer.
 
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Jake_Robbo

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Using hydrometer to take readings. The og readings have been around 1040 give or take.
the cans are supposed to come out at about 4.5%-5%.
it’s just one can that is 1.7kg and dextrose dark malt mix is 1kg.
 

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Gnomebrewer

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A kit'n'kilo should give you somewhere in the low to high 4% range in 20 to 23L. What was the FG?
 
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Jake_Robbo

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A kit'n'kilo should give you somewhere in the low to high 4% range in 20 to 23L. What was the FG?
OG 1040 FG 1022. Far too low for a basic kit. 23L of water as per the instructions. The brews taste good, I just want full strength beer.
 

Gnomebrewer

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The FG is the issue - those kits with some malt+dextrose added normally finish below 1.010 (often more like 1.005). More often than not, the high FG reading is because a refractometer is being used, but that's already ruled out. So, either there's an issue with the ferment (too cold or unhealthy yeast or not fermented for long enough) or an error with the measuring equipment. Have you checked your hydrometer in water to make sure it reads 1.000?
 
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Gnomebrewer

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The other issue could be due to the amount of non-fermentables in the kilo packs. Does the creamy stout mix have lactose in it? That'll boost the final gravity because it won't ferment. The same with maltodextrin in the Morgan's body kit - they don't say how much of the kilo is dextrose and how much is malto. Try making another stout and just add 500g of light, dry malt extract and 500g of dextrose. If you want it a bit stronger, make it up to 20L instead of 23L.
 
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Jake_Robbo

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The other issue could be due to the amount of non-fermentables in the kilo packs. Does the creamy stout mix have lactose in it? That'll boost the final gravity because it won't ferment. The same with maltodextrin in the Morgan's body kit - they don't say how much of the kilo is dextrose and how much is malto. Try making another stout and just add 500g of light, dry malt extract and 500g of dextrose. If you want it a bit stronger, make it up to 20L instead of 23L.
I have made some with lactose that give me a higher OG and FG. They have finished a little stronger but still not as high as they should be.
I am no expert at reading these hydrometers but I have had 5 long necks in a sitting and felt like I have been drinking water.
Your suggestions I’m sure would help boost the alcohol content, but it shouldn’t be needed so I’m wondering what I am doing wrong. Would fluctuation in temperature during fermentation effect it possibly?
 

DannyBoy270

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I have made some with lactose that give me a higher OG and FG. They have finished a little stronger but still not as high as they should be.
I am no expert at reading these hydrometers but I have had 5 long necks in a sitting and felt like I have been drinking water.
Your suggestions I’m sure would help boost the alcohol content, but it shouldn’t be needed so I’m wondering what I am doing wrong. Would fluctuation in temperature during fermentation effect it possibly?
From what you said above your FG seems too high. For one reason or another fermentation is stalling out on you. Temperature can definitely be a factor; too cold and the yeast go into hibernation, too hot and you can damage the yeast cells. But if you're somewhere between 65-75 degrees consistently it shouldn't really be an issue.

How are you pitching your yeast? I.e. starter, rehydrate, or straight from the pack?
 

bracconiere

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I just want full strength beer.

being that it's coopers....why not add a shot of vodka?...but that's just a joke....

i read you say you know from the feel, but that's really not presice...never know what the spirits are thinking....could there be stratification with the OG, sugar and water take some persuasion to get along... :mug:
 
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Jake_Robbo

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From what you said above your FG seems too high. For one reason or another fermentation is stalling out on you. Temperature can definitely be a factor; too cold and the yeast go into hibernation, too hot and you can damage the yeast cells. But if you're somewhere between 65-75 degrees consistently it shouldn't really be an issue.

How are you pitching your yeast? I.e. starter, rehydrate, or straight from the pack?
I have a heat pad to ensure that it is not getting too cold and I don’t let it get too hot, but, it does fluctuate a bit.
Yeast just goes in straight from the sachet that comes from the tin. I thought boiling it would kill the yeast.
 

JeffD

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Your FG should certainly be in the 1.005 - 1.010, but your OG seems low too. You didn't say how long you ferment your batches, so that could be one problem. Let them go for a good two weeks before bottling. I'm curious to know if you can detect an appreciable sweetness to the final beer? If so, you're just leaving unfermented sugars by not fermenting long enough. If not, you may not have started with enough sugars. When you pitch your yeast, what temp is the wort? And do you see vigorous bubbling and foaming action after 1-2 days of pitching the yeast?

When I started, I tended to brew batches with lower than expected ABV, but more like 4.5%-6% rather than 6%-8%. I've added extra grains (oats) and let the fermentation go longer - both to good effect. Your OG is a bit low, so you could consider adding more malt extract or other form of sugar.

In the end:
1) make sure your yeast is vigorous. You may want to consider starting your yeast in a warm solution of water and extract or even sugar.
2) Make sure you OG is up to spec. Add more extract if necessary.
3) Let the batch ferment for at least two weeks at about 72deg or whatever temp your yeast instructions recommend. Avoid the heating pad. The cooler your environment, the longer your brew will need to ferment. I've lagered beers for over a month after an initial 10 days at warmer temps.
4) Use a sanitized thief to pull out a sample to test for FG and if still to high, let it ferment a few more days.
 

DannyBoy270

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I have a heat pad to ensure that it is not getting too cold and I don’t let it get too hot, but, it does fluctuate a bit.
Yeast just goes in straight from the sachet that comes from the tin. I thought boiling it would kill the yeast.
Right, definitely do not boil the yeast lol I was curious if you might be rehydrating it in water that was too hot or something.

Personally I suspect the issue has to do with the viability of whatever yeast your using, because ideally the fermentability of your wort should be more or less predetermined when you're using extract.

I would consider:
1) How has the yeast been stored? (from where you purchased it)
2) How are you storing it? (Specifically are you keeping it at the recommended temp range)
3) What temperature are you cooling your wort to prior to pitching the yeast? Again as you said too hot could kill some of the cells

Additionally, adding some yeast nutrient could aid your cause (if you haven't already tried that); or if 2 weeks of fermentation has passed and your FG readings are still high you could always attempt to pitch more yeast and see if they come down anymore. Likewise, I know you said you've made 5 batches now, but if you've used the same yeast for all of them thus far maybe consider trying a different strain as well.
 
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Jake_Robbo

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Batches fermented minimum two weeks, sometimes three. The wort has been 25 degrees Celsius (Give or take 1 degree) when pitching the yeast. Vigorous bubbling for a couple of days then it has slowed down for a few more days. I have used a couple of brands and different types of beer so I wouldn’t think it’s the yeast strain. I have only been storing them at home for a day or two before using And the brew shop always seems to be a pretty constant temperature but who knows before that.
The og is pretty close to what the product specifies. The Irish stouts day around 1038 but with adding the milk stout mix I have been getting more like 1050 and then a FG of 1023. I have checked it multiple times after the initial fermentation and it hasn’t dropped any more. Is rehydrating the before pitching a normal thing?
 

DannyBoy270

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Dry yeast often has instructions for rehydrating on the package, but just pitching it in is fine too. Here's a separate thread on that if you really want to know : General yeast question

What yeast are you using? If it's just a package that comes with the kit you may not be pitching enough yeast. Everything else you've described seems fine, I'd try pitching more yeast next time and maybe up your fermentation temperature slightly to further boost activity.

Like @JeffD mentioned I'd be curious if you can detect an additional sweetness in the taste, as that would indicate there is still unfermented sugar present.
 

Redpappy

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Have you thought about buying a separate package of yeast to try with the kit? Have heard that you get old yeast with some kits...
 
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Jake_Robbo

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When I bought my brew kit I was given a run down on how to brew. I was told at the end to stir it right up and get a good swirl going then sprinkle the yeast over the top but not to stir it in. Is it possible that this has maybe not activated the yeast properly and this is why it hasn’t broken down all of the sugars?
 

Gnomebrewer

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Unlikely. I pitched yeast like that lots of times early on and they always worked.
 
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Jake_Robbo

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Unlikely. I pitched yeast like that lots of times early on and they always worked.
Well I got myself a fridge and an ink bird temp regulator. I have a dark ale down now and this is the first time using this system so hopefully keeping it warm and constant will help as well. If this doesn’t work I don’t know what will.
 

Gnomebrewer

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Did you use the kit yeast? What ingredients did you use for the dark ale?
 
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Jake_Robbo

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Did you use the kit yeast? What ingredients did you use for the dark ale?
Yeah kit yeast. The bubbling seems a lot more intense than it has in the past. It’s a Morgan’s Australian old with 1kg superior body which is some light malt, dextrose and corn syrup, also added 500g of dark malt and goldings finishing hops. It’s supposed to be a tooheys old dark ale.
 
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