I have a batch fermenting at the moment. I had expected the OG to be 1.05x but it was 1.06x. I generally have little problem with fermentation and expect the batch to come out at somewhere like 1.0.1x.

This will probably make the beer >6%.

I was going to rack to secondary after fermentation had stopped. Is it possible to add water into the secondary to decrease the ABV? How much can I and should I add to get it more to 5.0-5.5%.

Batch size in the primary is 43L with about 6L of relatively heavy trub.

  • If you have some more precise measurements (estimated OG, actual OG, estimated volume, actual volume), we'd be able to give you some precise water amounts to add to get you to where you want to be.
    – Scott
    Oct 2, 2013 at 2:30
  • I'm more wanting to know if is a common thing and if so what the normal process would be to "water it down". Fermentation is still ongoing at the moment so I'll know for sure next week.
    – jptew
    Oct 2, 2013 at 9:29
  • 5
    If I were you, I'd celebrate my high mash efficiency and enjoy some 6% beer!
    – pjreddie
    Oct 3, 2013 at 16:56

4 Answers 4


You can dilute/blend your beer to diminish the ABV (and increase the volume).

Brew Your Own magazine has a nice article on that.


BE SURE to boil any water you add at this point to deoxygenate it. If you don't, the added water will oxidize your beer and promote faster staling.


I believe it will be possible to add extra water to decrease the ABV but is it really necessary? If so I would get purified water and for a 43L batch add a few liters to decrease the ABV. Do this in the new carboy before racking the brew into it. If it was me I would leave it though. As mentioned by others without having the exact readings it is hard to say how much/little to add.

  • It isn't necessary, the last few brews I have done have been 8%+ and I was targeting something a bit less this time but efficiency was higher than expected.
    – jptew
    Oct 2, 2013 at 9:30

When you add water, make sure you don't get chlorinated water like some cities provide. The yeast doesn't like the clorine and you could get problems with bottle carbonation.

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