I just brewed a witbier that was way below the estimated preboil gravity of 1.49. I only got 1.34 in case you're wondering. I've never had that bad of an efficiency before. The grains came prepackaged and my guess it that either the total weight of the grain was light and/or some of it wasn't crushed properly. Or, for whatever reason my brewhouse or my brain decided to take a break that day. RHAHB.

To get it back up to the expected preboil gravity I added DME to get it to 1.49, or so says my hydrometer after my temp adjustment. I must have done something wrong in my calcs, because my OG ended being 1.66 instead of 1.56. That, combined with my yeast starter is going to prove a very boozy witbier. More than I want, actually.

I've already pitched and want to see through the fermentation process without topping off, partly because I want to see if I can notice the difference (isn't that what homebrewing is all about?) and partly because I don't want to mess with the primary since my blowoff tube looks like I've just brewed a DIPA. If I find it too boozy am I able to top-off after the primary?

I can always add water in the secondary or the keg before I force carbonate. Physically adding water to reduce the PPG in not an issue, but I'm not sure if there are any ramifications to the beer itself.

2 Answers 2


Adding water after primary fermentation is possible and called high gravity brewing. Yeast produce more esters at higher gravity which is a disadvantage for most beer types, but often desired e.g. for Hefeweizen. For a witbier is shouldn't be a problem, either.

  • 1
    I do it with my Belgian Pale Ale. I ferment 20 liters and bottle 30 liters. Works like a charm, really good effects with my recipe and yeast. Belgian styles need esters :)
    – Mołot
    Commented Dec 19, 2016 at 18:58
  • That is a great article. I had no idea that dilution (of a certain percentage) could help me increase my capacity!
    – mike0416
    Commented Dec 19, 2016 at 20:08

The answer above is partially incomplete and partially incorrect. Yeast do not necessarily produce more esters at higher OG, although it is possible. Using the proper amount of healthy yeast, that can be avoided. That's th partially incorrect part. The incomplete part is that while you can certainly add water post fermentation, you want to preboil the water to deoxygenate it, then allow it to cool covered so it doesn't reabsorb too much O2. Preboiling to deoxygenate will prevent the water from oxidizing your beer. We discuss just this issue on Episode 30 of the Experimental Brewing podcast, available as of 12/21/16 at www.experimentalbrew.com if you'd like more info.

  • Thanks for the info. I'll be sure to check out the episode. To be fair to the answer above, I do believe that water treatment is considered heavily in the article that was mentioned.
    – mike0416
    Commented Dec 20, 2016 at 20:27
  • 2
    Yeast produces at higher gravity disproportional amounts of esters (see e.g. Back et. al, Hefeweizenbier – Geschmacksvarianten und Technologie, Brauwelt Nr. 28/29, S. 1279-1284 (1998)). Below a given point, this can of course be compensated with a higher pitching rate, lower fermentation temperature or pressurized fermentation. At really high gravity, these is probably not possible anymore because the ester producing process is disproportional. Commented Dec 21, 2016 at 18:35

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