Adding Water After Fermentation!

[Grizwald]

Hi all,

Need a bit of help!

So, I have brewed 2 batches of IPA based on the same recipe - the first batch is now bottled (OG: 1.062, FG: 1.011, so ABV 6.7%), which was a bit stronger than desired but all good.

On the second batch, I added more sparge water to get a weaker ABV (target 5.5%) but something went wrong (measuring error) and it turned out exactly the same ABV after fermentation as the first batch. I really don't need another 40 bottles of that strength!

So, I am considering doing the following when bottling:

1. Calculate an additional amount of water to add that will bring the ABV down to 5.5%
2. Prepare additional water by making sure it is boiled and sterile and then allowed to cool to match the beer temperature prior to adding.
3. Add the additional water
4. Check FG
5. Prime in the normal way, based on the new volume

Now, i know that will make some of you wince - good beer being diluted, but I can't see another way and don't really want this to be a thread about the demerits of doing it!

I should also add that the beer is currently extremely hoppy and quite thick so an element of flavour dilution should hopefully be within tolerance to maintain an IPA taste.

Anyway, my questions:

1. Is there a better way of doing this than the steps above?

2. How do I calculate how much water to add before bottling to get to the desired ABV? (5.5% rather than 6.7%). Is there a calculator somewhere for this?.

Thanks

[Paddington]

There is a good calculator on Brewers Friend for dilution. I believe 'liquoring back' is an accepted technique (obviously with the right sanitation) and I've done it when I have lost too much to evaporation.

[Eric]

40 pints @ 6.7% ABV contains a similar quantity of alcohol as 48.7 pints @ 5.5% ABV.

Your 6.7% IPA should be at pH 3.7 to 4.2 which can be significantly increased by adding highly alkaline water which in turn can impact beer flavours. Otherwise you should have few problems doing what you outline as yeast with priming sugar will tidy up all else.

[Paddington]

Eric - that's helpful. Can I ask two questions: 1. is it ok to use water from the tap (I have been advised this is OK if the tap is sanitised and then run for a minute) 2. should the tap water be treated to address the PH issue.

[Robwalkeragain]

Pre ferment is fine, post ferment not so good. Yeast will scavenge oxygen from the ferment once it's complete, when you add water it's packed with oxygen, and you need to rely on the yeast to chobble up a lot of oxygen. I'm not saying it won't work, but it's definitely not best process.
Tap water should at least be dechlorinated and sterilised before use. If I absolutely had to do this I'd probably dechlorinate the water with Campden, heat it to 80c+ to sterilise and then add when it's cool.

[Paddington]

Rob - are you saying heat to 80 pre ferment or just post? I only add water pre ferment.

[Eric]

I would suggest that provided you run your tap for a little while before taking what you need, you should have no problems associated with sanitation, especially when the pH of the beer remains where it should be.

You boiled your wort for an hour or more and amongst the many changes that took place, most natural alkalinity that your water contained would be deposited with a miriad of other components. If now you add back alkalinity when the yeast has mostly finished its work, pH will be increased to the detriment of both flavour and resistance to bacterial infection. What degree of alkalinity is acceptable I don't know and wouldn't like to guess, but the final pH of a well made beer will be less than the level accepted as the end point in measuring alkalinity, i.e. 4.4. To that end I would suggest you acidify your tap water to obtain a pH reading of between 3.7 and 4.2.

Don't worry about oxygen until there are no fermentable sugars and/or no active yeast. The amount of oxygen dissolved in fermenting wort is a very few parts per billion.

EDIT. If you have concerns that your tapwater contains a large amount of chlorine, then you should take that into account. Mine has no such problem.

[Robwalkeragain]

Rob - are you saying heat to 80 pre ferment or just post? I only add water pre ferment.

Probably both, water is full of bugs and chlorine, any water added to beer should always be treated! Your aims are to remove chlorine and sanitize the water, plenty of ways to do it, but I'd always suggest doing them...

[HTH1975]

If I was going to liquor back post-fermentation, then bottled water would be my choice.

[Grizwald]

Thanks for the amazing responses folks!

There is a good calculator on Brewers Friend for dilution.

Ok so trying to work the Brewers Friend calculator out, Ive calculated that I need a gravity of 1.020 to get an Abv of 5.5%. Using the calculator based on a 15l batch, I have worked out that I need to add 7.5l of water.

That seems a lot to me??

[Kev888]

More or less in line with what has already been suggested: I would suggest diluting with water adjusted to approximately pH 4.0 or slightly lower to match the beer. After that it comes down to cases. If there were significant chlorine or chloramines (or the possibility of them) then I would treat with campden tablets or sodium metabisulphite first.

If it were to be drunk more or less when ready then I personally wouldn't bother to boil the dilution liquor. If the IPA was to be kept a long while (i.e. months) afterwards, then I perhaps would boil (and cool) as belt and braces against infection. If it were actually something more like an APA (where hop aroma is to be preserved as far as possible) there again I might bother, for more immediate oxygen reduction. (All the above assuming live yeast in the beer, anyway).

It might also be relevant to remember that IPAs 'were' brewed and shipped quite strong, then sometimes later diluted before drinking. Mostly to maintain the alcohol's deterrent against infection and probably partly to reduce shipping volumes. I can't immediately see a problem with following suit, and diluting (with suitably prepared liquor) prior to drinking. It could even be done pint by pint to help you assess the effect without detriment to the remaining batch.

(EDIT: apologies, your post appeared whilst typing; i've not used that calculator so can't comment on it, but I think it might be confusing the issue to attempt using gravity. At this stage, simple dilution of existing alcohol is all that is needed, which can just be calculated by volumetric proportions or ratios)

[orlando]

If I was going to liquor back post-fermentation, then bottled water would be my choice.

For simplicity it appears to be a reasonable work around, just doesn't deal with the pH issue. Not a problem if the Beer is going to be consumed quickly as there will be less time for spoilage to occur. More of an issue if ageing is the aim.

[timstaley]

I have successfully used bottled carbonated water in the past deals with the PH worries and the oxygenation problem
Tasted ok too

[Jim]

While the warnings about chlorine and sanitation seem reasonable (especially chlorine) many kit brewers use water straight from the tap without serious problems, so it can't be that bad. Maybe just a tiny bit of a campden tablet or use a water filter?

[Kingfisher4]

I have successfully used bottled carbonated water in the past deals with the PH worries and the oxygenation problem
Tasted ok too

Interestingly, many of the bottled water varieties seem to have quite a high pH. Tesco Ashbeck water is the lowest I have found, Only became aware of this because of the potential problems with diluted starsan which quite rapidly goes milky and becomes apparently less effective in high pH water, e.g. our tapwater.