Low ABV problem.

The Homebrew Forum

Help Support The Homebrew Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

mrfog

New Member
Joined
Jun 20, 2020
Messages
6
Reaction score
13
Greetings all. First time poster so please be kind :) As many others I have started homebrewing due to lockdown etc. and I have really enjoyed it. Did a Muntons APA to start with which was ok but I was far to impatient and drank it early not realising that it needs time to develop. Currently in bottles I have the Simcoe IPA from Mangrove Jack which after 2 weeks is just about ready to go in the fridge to clear for another couple of weeks. I've already tried one or two of those and they taste great with excellent carbonation so really looking forward to that one in a few weeks.

However I have the following couple of problem 40 pint single tin brews going at the mo.

Wilko Chocmeister
For the 1Kg of sugar the kit requires I subbed 500g DSM and a 454g tin of molasses
SG 1034
Added Willamette dry hops at day 7
Been going for 10 days and has stopped at 1014 now for 2 days.
By my calculations this will come out at 2.62%
It does taste nice however.

Crappy Lager that came with my equipment
For the 1Kg of sugar suggested I subbed 500g DSM and 500g dextrose
SG 1022
Added Montueka dry hops at day 7
Been going for 10 days and has stopped at 1010 now for 2 days
ABV should be 1.57%
Again it tastes ok.

Right, so you can see where my inexperience and naivety has come in. I have just subbed weight for weight on sugar rather than understanding the SG to determine the outcome.

My question is this: Would it be a good idea to get these into a secondary with some dextrose to get the ABV up a bit? I've read conflicting stories on this, some say it will do nothing while others say it will thin out the brew. Any help is much appreciated.
 
Are you sure about those ABVs? Did you correct for temperature and/or take a sample when it was well stirred? They seem awfully low, I'd be very surprised at a kit having an SV of only 1.022 and your true SV should be very close to what the kit specifies.
 
Are you sure about those ABVs? Did you correct for temperature and/or take a sample when it was well stirred? They seem awfully low, I'd be very surprised at a kit having an SV of only 1.022 and your true SV should be very close to what the kit specifies.

Temperature was easily controlled and measured at approx. 20C after topping off.
Are you saying it's pretty impossible for a kit to be that low ?
 
Temperature was easily controlled and measured at approx. 20C after topping off.
Are you saying it's pretty impossible for a kit to be that low ?

Sample temperature, hydrometers are calibrated to a certain temperature (20 deg C in my experience) and won't read correctly when the sample is hotter/colder, the reading needs to be adjusted (plenty of calculators online) if the sample temperature was different to the calibration temperature. They shouldn't be used at very high temps either, 60 deg C is the generally excepted limit iirc.

It often catches me out, I've taken a few samples in the past at close to boiling and got away with it but cooled samples can still be out by a few points without feeling warm, I'll mostly leave them to stand for about half an hour before trusting the reading now.

Impossible for a kit to be that low... yeah, I think with the amount of sugars you've added it's impossible for your OG to be that low (but I'd have to look up the figures to be 100%), the supplied ingredients would certainly have pretty much zero sugar content for the OG to come out at 1.022.
 
Sample temperature, hydrometers are calibrated to a certain temperature (20 deg C in my experience) and won't read correctly when the sample is hotter/colder, the reading needs to be adjusted (plenty of calculators online) if the sample temperature was different to the calibration temperature. They shouldn't be used at very high temps either, 60 deg C is the generally excepted limit iirc.

It often catches me out, I've taken a few samples in the past at close to boiling and got away with it but cooled samples can still be out by a few points without feeling warm, I'll mostly leave them to stand for about half an hour before trusting the reading now.

Impossible for a kit to be that low... yeah, I think with the amount of sugars you've added it's impossible for your OG to be that low (but I'd have to look up the figures to be 100%), the supplied ingredients would certainly have pretty much zero sugar content for the OG to come out at 1.022.

I see, this is one of those learning moments then I guess, thanks very much for that, will have to be careful with that next time. I guess I'll leave it alone and proceed with 2/2/2 and see how many pints gets me happy.
 
Your fg look fine. If they're stable bottle. You could punch your numbers into a calculator and that would give your approx abv...but if it tastes nice your in a winner anyway!
 
@mrfog
It is essential that you thoroughly mix all of your malt extract and any other sugars at the outset before you take your SG reading. If you have liquid malt stuck to the bottom of the FV or clumps of undissolved dry malt etc etc your OG will be artificially low and so will your calculated ABV. The good news is that even if all of the malt and sugars are not fully dissolved at the beginning they get dissolved in time and consumed by the yeast, so the ABV will not be far off what it should be. Next note that different sugars have different potential to be fermented. So table sugar> dextrose>DME>LME. And so by subbing DME and molasses for table sugar in your stout kit your beer will have a lower ABV, but that's not so bad, because it will likely taste better athumb..
 

Latest posts

Back
Top