Grain Absorption Rate in Beersmith

I brewed a Bourbon Barrel Porter All-Grain kit from Northern Brewer yesterday, and had a strnge thing happen – at least I think it was strange. I plugged the recipe into Beersmith along with my equipment profile, which I’ve used before. BS told me I would need 8.57 gallons of water, total – and that after mashing I would have 6.72 gallons going into the boil. I did a single infusion, medium body, batch sparge for the mash. When I was finished with the sparge, I wound up with around 7.4 gallons. To me, this would indicate that the actual grain absorption rate was a bit lower than Beersmith’s default setting. Has anyone had any experience with this? Is this yet another parameter that can vary from batch to batch, grain to grain? At least with SRM’s and IBU’s, those are listed on the grains and bags of hops, so that you can plug the info into your recipe and modify accordingly, if need be. How can you predict absorption?
I will say, the pre-boil gravity was higher at 1.052 than the anticipated 1.050 – so I was not disappointed. I’m just wondering where all the extra wort came from?

You should keep track of absorption yourself over several brews until you get enough numbers to create an average, then you can tune your software accordingly. And yes, it does change depending upon the grist: wheat does not absorb as much as barley, flaked oats absorb a different amount of water than flaked corn, or rice, or rye, etc...all depends on the percentage of said ingredients in your recipe. Not so critical if you're fly sparging, but batch spargers and BIABer's need to be cognizant of this.

Keep BeerSmith's initials in mind.

thughes said:

You should keep track of absorption yourself over several brews until you get enough numbers to create an average, then you can tune your software accordingly. And yes, it does change depending upon the grist: wheat does not absorb as much as barley, flaked oats absorb a different amount of water than flaked corn, or rice, or rye, etc...all depends on the percentage of said ingredients in your recipe. Not so critical if you're fly sparging, but batch spargers and BIABer's need to be cognizant of this.

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Aye! So much to absorb! (no pun intended) I'll keep an eye on it through succeeding brews. So far I've only done two all-grain brews, and I didn't notice whether or not the first one was so far off - maybe a little bit over but I don't think THAT much. I'm happy it didn't negatively affect the brew, at least as far as gravity goes.

Thanks.

BrewMU said:

Keep BeerSmith's initials in mind.

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Ooh, not a BS fan, eh?