What are the effects of having too much water in your mash? If it's too "soupy" or watery or whatnot.

  • How much is "too much"? In qt/lb would be nice. Commented Jul 18, 2010 at 18:46
  • Right now I'm looking at about 21-23 qts and 14.5 lbs. So 1.5+ qt/lb Commented Jul 18, 2010 at 18:49
  • But, generally speaking, what if it was like 5qt/lb? 50? Commented Jul 18, 2010 at 18:49
  • Great question, great answers. I've always wondered about this and now I know. Thanks to all.
    – Juanote
    Commented Jul 19, 2010 at 1:02

2 Answers 2


As homebrewers we're used to 1.25-1.5 qts/lb. But in some pro brewing set ups they mash in one vessel and lauter in another. In order to transfer from one vessel to the next they use better than 2qts/lb in some cases for pump-ability.

Some speak of getting a thinner beer with a thinner mash, but i think within 10-20% of the target thickness you won't see much of a difference.

More water does dilute the enzymes to an extent also, which has an impact on conversion time. But the relationship between enzyme and substrate ratio for conversion efficiency and time is not a linear relationship. So at the end of the "curve" we are operating in there is tolerance for more water than expected, and very little if any change in conversion time is seen.

Keep in mind most of us mashing for 60mins tend to mash longer than is actually required to convert. So 60 minutes will still cover you even if you use 2X-3X water.

  • I use 2qts/lb for all my brews Commented Jul 19, 2010 at 0:08
  • Yeah, I've been in the 2qt/# range too and seen no difference in efficiency or body. For what its worth, people do infusion step mashing and the water to grist ratio is changing the entire mash. Second to that you often end up with a mash at the end of infusion step mashing higher than 2qt/#. So nature has a pretty good tolerance built into itself in this aspect of brewing parameters.
    – brewchez
    Commented Jul 19, 2010 at 12:21
  • Right. I suspect you have to get up to ridiculous water to grist ratios before running into a problem. Even then, continuous stirring would probably solve that problem. Commented Jul 19, 2010 at 15:21

The major effect is dilution of enzyme concentration. In a watery mash the enzymes take longer to convert starches.

While it takes longer to convert, you will ultimately end up with a more fermentable wort because high concentrations of sugars hinder enzyme action.

See Manipulating the Starch Conversion Rest

  • How about the lack of a good grain bed too? Commented Jul 18, 2010 at 19:45
  • 1
    Nah, the grain settles pretty well. A good vorlauf will set up your filter. Commented Jul 19, 2010 at 0:10

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