Increasing final % ABV

MattP

Does anybody have any thoughts on the best way to increase the final % ABV ?

To be honest I've always been a bit disappointed with my results with regards to this factor, and have found it diffacult to achieve the acctual % ABV which kits suggest should be possible. Whilst I'm not desperate to produce hugely potent brews (all the beers I've made have tasted ok, and that's what's important), purely for the sake of interest I'd like to be able to produce the odd strong ale.

To give an example, I have a batch on the go at the moment based on an Edme Irish Stout kit, and I thought I might try to up the alcohol level of the final product. The keg I'm going to finish it in is slightly larger than normal and will easily take 50pts rather than the normal 40pts, so I've added the extra 10pts of water to suit the barrel. To compensate, I've added an extra .25kg of sugar, 900grms of Muntons dark malt extract and 500grms of their  extra dark spray malt. However the original gravity of this wort is still only 1.05 OG. By my calculations, even if the fermentation brings the FG down to 1.01, the final alcohol content would still only be around 6%, which is the suggested level suggested in the description on the can. The fermentation went off like a volcano for the first 12 hrs and has now settled down a good steady buble every 1 - 2 seconds, so it seems to be going ok. I'm just surpried that all the extra sugar didn't raise the OG more.

Accepted wisdom seems to be that it's better to reduce the water in a brew rather than increasing the sugar, in order to raise the %ABV, but as I don't use bottles but always keg the resulting beer, I don't really want to brew half a barrel's worth.

I also remember reading that different yeasts will tolerate different sugar levels,(I used Muntons Gold yeast for the above brew), and also alcohol levels in the final product before they cease to work. Has anybody tried using one of the currently available "Turbo Yeasts" ? I think that these are intended to ferment sugars to a high level of alcohol as a precursor to distillation into vodka etc ? Has anybody tried using them in a beer brew, or know if the'd make an appreciable difference ? What effect might they have on the taste ?

HBO_Staff

Generally speaking we would agree, the main way it is done is by reducing the volume of liquid, which can help to concentrate the flavour and increases the alcohol level. The problem with adding sugar is that brews can turn out too sweet if you over do it, the extra spraymalt used will undoubtedly help. The turbo yeast is not something we have tried, and you're right with what you say about their intended use, they are then distilled to purify them and generally flavoured essences are added when bottled to give it whatever flavour you want. We have had feedback from 'Brewermirk' who decided to experiment with a batch of scrumpy and turbo yeast, it's copied and pasted here for your info;

By Brewermirk from lutterworth on 11/03/2011

I had made a medium sized batch of scrumpy but after two weeks infusion in the crushed fruit the liquer tasted sweet and not very alchohlic. I added a quarter of a pack of Turbo 48 and it went crazy resulting in me having to add more and more sugar untill two weeks later i stopped feeding it and let it settle down. The result was 40 pints of mega-scrumpy that doubles as an anaesthetic if taken in moderate amounts,

MattP

Hmm.. Not sure I understand the difference between adding more sugar (in whatever form) and reducing the amount of water added at start of fermentation. It seems to me that effectively the result is the same, ie increasing the proportion of sugar to water in order to up the original gravity at starting point ? The only question is whether the yeast is able to cope with the extra sugar and convert it to alcohol ? If not then I imagine the unconverted sugar would indeed make the final brew overly sweet (at least for my personal taste).

I'm just wondering if there is a formula which calculates how much extra sugar you need to add (or how much water needs to be reduced by) in order to increase the final %ABV by a given amount. I added what seemed to me quite a lot of extra sugar but acctually the effect on the OG didn't seem to be that great ?

The Turbo yeast sounds interesting though. An experiment for the future perhaps.

MattP

Hmm.. Not sure I understand the difference between adding more sugar (in whatever form) and reducing the amount of water added at start of fermentation. It seems to me that effectively the result is the same, ie increasing the proportion of sugar to water in order to up the original gravity at starting point ? The only question is whether the yeast is able to cope with the extra sugar and convert it to alcohol ? If not then I imagine the unconverted sugar would indeed make the final brew overly sweet (at least for my personal taste).

I'm just wondering if there is a formula which calculates how much extra sugar you need to add (or how much water needs to be reduced by) in order to increase the final %ABV by a given amount. I added what seemed to me quite a lot of extra sugar but acctually the effect on the OG didn't seem to be that great ?

The Turbo yeast sounds interesting though. An experiment for the future perhaps.

MattP

Hmm.. Not sure I understand the difference between adding more sugar (in whatever form) and reducing the amount of water added at start of fermentation. It seems to me that effectively the result is the same, ie increasing the proportion of sugar to water in order to up the original gravity at starting point ? The only question is whether the yeast is able to cope with the extra sugar and convert it to alcohol ? If not then I imagine the unconverted sugar would indeed make the final brew overly sweet (at least for my personal taste).

I'm just wondering if there is a formula which calculates how much extra sugar you need to add (or how much water needs to be reduced by) in order to increase the final %ABV by a given amount. I added what seemed to me quite a lot of extra sugar but acctually the effect on the OG didn't seem to be that great ?

The Turbo yeast sounds interesting though. An experiment for the future perhaps.

bertro

The Stevenson wine and beer hydrometer has an instruction leafle included that tells you how to calculate the amount of sugar to add for a specific gravity. Its called the Brix/Balling/Plato formula