Increasing ABV after primary fermentation

[gmc]

Hi all,

I am new to home brewing. I have my first batch on and after taking my readings it looks like I am at final gravity with a couple of consecutive gravity readings. I am making a kit and largely following the instructions. After using an ABV calculator it looks like I am at around 3.7% instead of the 4.5% I was aiming for. I have a few things to improve for the next batch which may have helped this one to reach a more appropriate ABV after primary fermantation, but given I have got what I have got with this batch, is there any way on increasing the ABV at this point of the process. If not, I will still prime the batch and bottle it for conditioning and see what its like, but if there are any techniques for increasing ABV at this point of the brewing process that are beginner friendly, I might give them a go.

Any suggestions will be welcomed!

 

[foxbat]

Yes there is a way, you can add a boiled and cooled sugar solution to the FV. The yeast will ferment all of those simple sugars and you will get a higher ABV and the final gravity you have now will remain the same afterwards. If your brew's fermentation stopped short (what was the FG?) then the higher ABV may balance the extra sweetness caused by that higher than expected FG.

Try this calculator to work out how much sugar you need: Gravity Adjustment Calculator - AleArchive.com

 

[gmc]

Thanks for the suggestion. My starting gravity was 1.036 and my final is 1.008. I have recorded 1.008 48 hours apart. The chart that came with the kit said the final gravity should be around1.009. It's a golden ale. I wasn't able to stir it as vigorously as I wanted when on brew day. I also just dumped the packed of yeast in as the instructions stated which on further reading is less than ideal.

 

[terrym]

In relation to your comment about stirring the wort in recent post a member asked advice concerning a low OG he had measured. Turns out he hadn't stirred the malt extract in enough, and after he did the SG went up.
So with a kit, with a known amount of sugars going in to make the wort, the correct OG will be in direct proportion to the sugars and start volume. It can't be anything else, although your hydrometer reading may suggest otherwise. So using the info below your OG can be calculated. Certainly when I did kits the calciulated and measured OGs were always the same. So...
What was the kit and what sugars did you add?
What was your start volume?
But all that said your OG might be correct for the kit you are brewing, so adding sugar as @foxbat has suggested will be the way forward to increase your ABV.

 

[Drunkula]

I wasn't able to stir it as vigorously as I wanted when on brew day.

Do you think your initial gravity might have been lower because of the goo being at the bottom of the bucket? It's happened to loads of us on here. First time it happened to me I only noticed because the bottom of the fermenter was piping where I'd poured in the swilled out can.

 

[foxbat]

Thanks for the suggestion. My starting gravity was 1.036 and my final is 1.008.

1.008 is a good FG, nothing wrong with that. It's the OG that look a bit low. Assuming you didn't add more water than required then like the others say it could be a measurement error due to the mixing and your OG could have been higher than you thought and your ABV might actually be where you want it.

 

[gmc]

What was the kit and what sugars did you add?
What was your start volume?
But all that said your OG might be correct for the kit you are brewing, so adding sugar as @foxbat has suggested will be the way forward to increase your ABV.

The kit was this one;

https://www.brewstore.co.uk/festival-golden-stag-summer-ale-beer-kit
I didn't add any additional sugars to the wort. I thought after some research that all the necessary starting sugars were contained in the liquid extract. The instructions did say to add sugar but I didn't include any, nor did it state how much so assumed those were instructions for one of their other kits. The instructions were terrible in general. When I added the extract, I added 3 litres of boiling water as per instructions and stirred that very well. The problem came when I added all of the necessary water and my fermentation vessel was too full to get a proper stir on. There was no guideline for the OG in the instructions either so I just carried on with 1.036 no knowing any different.

My starting volume was 23 litres. It might have been a touch over as I added 3 litres of boiling water and 20 litres of fresh water, forgetting that the extract also had a volume, even if it was fairly low. 300ml maybe?

If I was to add boiled and cooled sugar solution to the FV how much should I add in terms of grams of sugar and litres of water. Also, how much longer would I have to leave it in primary fermentation before bottling. I think in it's current state, primary fermentation is complete.

 

[gmc]

I also assume it is was too late to stir it now if there is excess extract at the bottom since it was been fermenting for about 17 days and the gravity is stable. I don't want to introduce oxygen at this stage and risk contamination.

 

[terrym]

I understand your Festival kit contains 3kg of LME (and nothing else other than priming sugar).
In 23 litres this produces a calculated OG of 1.038 ( see here Beer Recipe Calculator - Brewer's Friend )
Your FG is 1.008.
Your yeast has done a good job since you have an attenuation of about 78%.
Anyway using these gives an ABV of 3.94%. ( Alcohol By Volume ABV Calculator - Brewer's Friend )
Adding say 100g of priming sugar will add another 0.2%. (total about 4.15%)
I have no idea why Ritchies claim 4.5%.
If its important to you to hit 4.5% you will need to add about 150-200g sugar as a concentrated cooled syrup (use boiling water to make the syrup which you need to gently stir in. If you have no dextrose, ordinary table sugar will be fine. Or you could use 200-250g of golden syrup, which, if I was going to do anything at all, would be my preference.
And I noted that in the description of the kit is needs 4 weeks conditioning
Hope this helps

 

[gmc]

I didn't realise that I would get as much as 0.2% from conditioning. I think hitting around 4.1% would be a success so I will crack on with the bottling in that case. I will be saving these tips for next time though if I feel like I am low on ABV.

Thanks for all the help ladies and gents. This seems like a very helpful community of people willing to share their time and expertise. I will be back to let you all know how it went