I’ve always mashed with a liquor-to-grist ratio of 1.25 quarts per pound of grain. Why? It was the example provided in my favored strike water calculator, and it never presented a problem. That is, up until I tried making a 10 gallon batch of a high OG beer using a 48 quart — there was no way all that grain and water was going to fit in the tun. Thickening the mash to 1 qt/lb and making two passes with sparge water helped me get through the brew day, though I wondered how this change from my normal process might impact the beer. It turned out totally fine.
Liquor-to-grist ratio is a fairly commonly discussed issue among brewers, with claims the thickness of a mash is directly correlated to wort quality. However, a growing number of anecdotal reports from brewers seem to suggest liquor-to-grist ratio may not as critical an element as we’ve been led to believe. From BIAB and no sparge brewers performing full volume mashes with ratios as high as 2 qts/lb to batch and fly sparge brewers mashing at 1 qt/lb in an attempt to squeeze as much grist into their tuns as possible, the range is vast and yet people are making good beer. Indeed, brewers are manipulating mash thickness for myriad reasons, but does it actually have a noticeable effect on the beers we’re producing?
To evaluate any potential perceptual differences between two beers of the same exact recipe mashed with different liquor-to-grist ratios.
For the 2014 holidays, I made a simple, minimally bittered American Pale Ale with Citra and Amarillo that ended up being one of the fastest kicking kegs I’ve ever put on tap. For this year’s festivities, I decided to make a similar beer utilizing hops I’d heard a lot about but never tried first hand, Rakau and Galaxy.
Since this was for the holidays and I wanted a spare keg for my sister-in-law’s wedding, a dual 10 gallon batch brew day was in order. I used to outline the differing mash temps and set to the task of mashing in both batches.
With the parameters dialed in for my normal 1.25 qt/lb mash procedure, I easily hit my target mash temperature. As a relative novice to the world of thin mashing, my calculations for the batch with a 2.5 qt/lb ratio were ever so slightly off, though not by enough to cause me too much concern, and the mash was decidedly closer to the rim of my tun.
I used the for these beers, which involved collecting the first runnings, stirring in a sparge addition, letting the mash settle for a few minutes, a brief vorlauf, then collecting the rest of the sweet wort.
Both beers went through a 1 hour boil during which hops were added at the prescribed times, then they were chilled to 185°F/85°C, the temperature the hop stand hops were allowed to steep. Finally, I finished chilling and took a hydrometer reading, noting a minor SG difference. Did mash thickness have anything to do with this?
I proceeded to transfer each wort into 6 gallon PET carboys that were placed in temperature controlled chambers. Each fermentor was then pitched with a of . Within 48 hours, both batches appeared to have reached high kräusen.
I dry hopped the beers 4 days into fermentation, noticing the activity had slowed dramatically. Three days later, I took a hydrometer reading that revealed a small difference with the standard mash beer dropping to 1.010 SG while the thin mash beer was at 1.012 SG.
It seems odd that a 0.7°F/0.4°C difference in mash temperature would produce such disparity and I personally suspect something else was at play, likely the variable of focus, but I can’t be certain. The beers were cold crashed, , transferred to kegs, then placed in my cool keezer where they were force carbonated. When it came time to collect data, both beers had a similar hop haze and were tasting delicious.
A total of 24 friends, family, and members participated in this xBmt, each one blindly presented with two samples of the thin mash beer and one of the standard mash thickness beer. Given the sample size, 14 tasters would be required to correctly identify the different beer to achieve statistical significance (p<0.05). When the dust settled, only 5 of the 24 tasters made the correct selection (p=0.90). These results suggest that in this particular xBmt with this particular recipe, this particular set of participants were not reliably able to distinguish between a beer mashed with a more normal liquor-to-grist ratio and one mashed thin.
My Impressions: The same. That’s my impression– these beers were exactly the same. Despite the 0.4% difference in ABV, I perceived the flavor, aroma, and mouthfeel of these beers as identical. Back-to-back, side-to-side, in a triangle… didn’t matter. In all of my trials, I never had a clue which beer was which, I could not reliably tell a difference.
We often caution readers not to make the mistake of misinterpreting non-significant results as meaning the variable has no impact. This is a good example of that– liquor-to-grist ratio did appear to produce a measurable difference in attenuation, albeit a small one, and I was somewhat surprised this didn’t impact perceptual characteristics. However, based on my personal experience and the results of the blind tasters, I’m left with the distinct impression mash thickness had little if any impact on the perceived quality of the final product. Having tasted great beers mashed at varying thicknesses, it’s hard for me not to view stressing over achieving a precise liquor-to-grist ratio as futile, though perhaps we’ll discover something different in future iterations of this xBmt.
One thing to consider when messing around with liquor-to-grist ratio, at least for those concerned about water chemistry, is that different mash thicknesses will produce different pH levels.
Ultimately, if liquor-to-grist ratio impacts the perceptual qualities of beer, I have to believe it’s well down the list of things to worry about, which is a relief! It means, to me, that we as brewers can be free to tailor our mash thickness to what’s being brewed or just to simplify the process without fear it will fuck up the beer. Whether a full volume BIAB or a thick mash Barleywine, the end result will be beer whose quality is likely determined by factors other than the ratio of liquor-to-grist.
If you’ve experimented with or have thoughts about the impact mash thickness has on beer, please share in the comments section below!
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Hops for this xBmt were provided by:
Grains for this xBmt were provided by:
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