Grain absorption ratios list

We've been doing lots of testing verifying our data vs. BeerSmith default values, and today I tested the absorption ratio of our main base malt. It came out much higher than the default value in BeerSmith.

Which made me think a thread where people can post their absorption rates for various grains would be useful for everyone. The format I think most useful is listing the maltster, malt, mill roller number, mill gap size, grist size percentages, and method. Here's ours:

• Maltster: Briess
• Malt: 2-row (branded as "Brewer's Malt")
• Mill roller number: 3 (The MM-3 Pro from Monster Brewing)
• Mill gap: 0.813 mm (0.032")
• Coarse grist ratio: 56.1% (#14 screen)
• Regular grist ratio: 24.2% (#30 screen)
• Fine grist ratio: 9.0% (#60 screen)
• Pan grist ratio: 10.7% (dust)

• Method to test absorption: Normal math used for such things, RO water at 170'F, 60 minute steep in a Styrofoam cooler with 170'F water bath surrounding the small 1 gallon kettle. Mash was stirred well at first, and every so often over 60 minutes (to replicate actual mash time).
  
• Method to measure grist and gap: NIST certified sieves, mill gap adjusted just before test, 3 minutes shake with hard knock every 30 seconds, test repeated once to verify results; grist collected as it fell from mill, not scooped from a pile.

• Absorption ratio: 1.4 fl. oz./oz.

P.S. Valid goal values for grist size, depending upon brewing method and beer, is 50-55% coarse, 25-30% regular, 7-9% fine, and 6-8% pan (dust).

There is no standard absorption based upon grain type.  It is mostly a function of grind and process.  If I took your grist and did my standard BIAB mash, I would end up with a different absorption rate than you get.  Ditto with my mash tun versus your mash tun.  Variations based upon grain are more appropriately sorted as barley vs wheat vs rye vs flaked grains, etc.

Once you have  figured out what your process gives you for grain absorption, you can change the universal setting under 'options' to reflect your numbers.

Yes, I'm aware there's no standard absorption for various grains. That's why I made this thread. BeerSmith assumes 0.96 fl. oz./oz. absorption rate across the board as far as I can tell, which of course isn't accurate across the board.

I doubt many users of BeerSmith know how to calculate values to adjust BeerSmith's default setting.

It makes sense to enter the value of the main grain comprising (often greater than 80%) the grain bill, or a mean of a brewer's most common grain bills, under the options setting. I use the ratio for 2-row base malt I listed in the first post (1.4:1) as a sufficient mean.

The variables you mention are why I provided the info I did, it should help other people use those data. The same for other people posting values they measure, as long as they list grist sizes, method, etc.

I don't see why mash tun differences would have any effect on grain absorption, it shouldn't.

The process of measuring grain (or any substrate) absorption is simple, although grain bed depth should affect the final last runnings volume.

BeerSmith has a default setting of 0.96 oz/oz for grain absorption.  This figure is available to modify to each users process, which is one of the things I like and appreciate about the program.

There are more than a few threads on this forum describing how to measure and adjust this setting to your process.

As for the mash tun affecting the grain absorption, the thickness of the grain bed, the area of drainage, and any pressure placed on the grain bed to compress and release free water all have a bearing on the residual water left in the grains after draining. 

By all means, if you can document differences between types of grains there are a number of us here who would be very interested.  Having documented different grists for water absorption for over 110 brews, I find that the minor variability in grain absorption lies more with my process than the inherent differences which may be in different grain sources or types.