What is the best way to handle a higher than expected extraction efficiency without compromising the flavor of the beer?

If I'm brewing a blonde ale for example, aiming for a 72% extraction efficiency and end up with an 80% extraction efficiency, it's going to significantly alter the character of the final beer. What should have been a 4% ABV might end up at 5.2% ABV, for example.

Logic tells me that diluting the wort by adding additional water will compensate for the higher than expected extraction, but it seems that diluting the collected wort will affect not only the color, but also the flavor as the added water didn't have the opportunity to mingle with the malt during the mash.


Sure, it would change the color, but isn't the color already altered due to the increased density of the wort? By adding water, you'd be diluting the SRM back to what you originally expected.

By having a higher extraction yield, you will suffer a slight loss in alpha acid isomerization (likely not all that noticeable with an 8%+/- efficiency difference). You'll be under-pitching your yeast if you do not account for the higher OG, so you'll likely suffer the consequences of under-pitching (ester formation, yeast stress, longer lag time, etc). Those are two of the most common concerns with higher than expected efficiency if it is not diluted back to what you expect.

I frequently account for higher efficiency by adding cold, filtered water at the end of the boil. This accomplishes two things. Primarily, it gets my OG back on track, and secondarily, it assists with chilling the wort. You could of course add the water pre-boil to get it back on track, and not suffer a loss in hop utilization, I just choose not to since I tend to go overboard on the hops anyways when I'm brewing a hop-forward beer. The consequences of adding water back into an overly efficient wort to get it back on track are minimal, if there are any at all. The sugars are dissolved in the solution, so as water is added, the sugars will blend with the fresh water all the same. If you choose not to dilute the wort, just be sure to pitch more yeast, as under-pitching can carry some very noticeable consequences.

  • Great explanation, thanks. Do you have a formula for determining dilution volume? – Matthew Mar 7 '14 at 19:26
  • Most common brewing tools (e.g. Beersmith) will come with them, here's Brewer's Friend's calculator. The mathematical equation is ((1000 - (1000 x actual gravity, e.g. 1.050)) ÷ (1000 - (1000 x desired gravity, e.g. 1.040)) x actual volume) - actual volume) = volume of water needed – Scott Mar 7 '14 at 19:43
  • Dilution will also lower the overall bitterness of the beer, irrespective of the lower hop extraction. Not much you can do about that post-boil, but if you know ahead of time you can increase your hopping to offset. – FishesCycle Mar 7 '14 at 21:30

Ideally, you would do this at recipe time. If you know your brewhouse efficiency, you can alter the grain bill to match your efficiency (by hand or using software). Doing it at brew time is going to have other impacts as Tobias Patton mentions. I have altered mine at brew time, by removing some of the wort and replacing it with water, but it kind of throws everything else off. Having said that, note that most brewers only change their base malts, likely for simplicity, but Jamil's Scottish ales are like that (use the same amount of specialty malts for 60/70/80).

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.