Grainfather: Large Grain Bills

[joegbeer]

Been brewing for 9 months on my Grainfather and I've done about 16-20 batches. Everything works great for "standard" recipes (10-15 lbs of grain). Note: I use a hop spider to improve the effectiveness of the pump. Occasionally due to some grist overflow during the mash, I have to take out the ball/spring from the top of the discharge pipe.

I've recently started attempting some big gravity stouts (5 gallon batches). I've done 18 and 19 lb batches in the GF. Recipes had about 1.5 lbs of oats. Sparging was rough, like 60-90 minutes. Problems hitting the preboil gravity on one by alot, and the other by about 0.04 (still more than I like to miss by). I definitely don't have brewsmith tuned perfectly yet, because I was missing my starting gravities by a bunch. Like expecting 1.1 and measured 1.090.

So I did another big RIS and scaled the recipe down to a final batch size of 3.5 gallons. I used 1 lb of rice hulls and had a total grain bill of 17lbs. Big problem I ran into here was the mash water calculator was only giving me .25 gallons of sparge water. Also got frustrated with beersmith not calculating my pre-boil volumes correctly for the reduced batch size, but that's a separate issue.

Should I be looking to scale recipes down, or investigating options like reiterated mashing (Grainfather Blog #74). How do you calculate mash and sparge water and consider the additional water absorption by the 2nd mash? Article wasn't clear to me. Sounds like they are calculating using the total grain bill? So even though 24 lbs of grain won't fit into the GF, if I'm going to do a reiterated mash with two 12 lb mash steps, I should still use 24 lbs for the water calculations?

I'd like to hear some tips and suggestions from other Grainfather users on how they handle brewing big beers (10-12%).

 

[joegbeer]

Anyone tried a reiterated mash on a Grainfather that can help with the water calculations?

 

[IchLiebeBier]

I've been wondering if you can use the Grainfather with a 10 gallon cooler as mash tun for larger grain bills. My thought is to connect a hose from the pump arm to the cooler top and a hose from the cooler valve back into the GF. By running the pump you could basically end up with a two-piece rims system (like the BrewEasy). Has anyone tried that?
At the very least you could just mash in the cooler, drain into the Grainfather and boil as normal

 

[pocketmon]

If what you concern is the efficiency, I don't think there will be a good simple solution.

I have about 82~85% efficiency for general 1.050 beer, but it drops to 65~70% for higher OG beer, like around 1.080. The problem is not conversion efficiency but Sparging. In my last bigger OG brew, the wort that dripped after I remove from the kettle had 1.040 SG. The grain bill was 16lb. If the grain absorbed 3.2gal wort for a rate at 0.2gal/lb, 128 points were lost.
To collect more sugar, more Sparging water and more boil-off are needed.

Reiterated mashing or IchLieBeBier's method make it possible to use more grain, but they can't solve the issue.

 

[IchLiebeBier]

I did a water only test the other day with my new GF. I haven't brewed with it yet since it was a Christmas present and the wife said I couldn't have it until then. But she doesn't know about the water test

Anyway, I put the cooler on a stool that was just high enough to allow it to drain into the GF. Then I ran a hose from the recirculation arm to the top of the cooler, and a hose from the cooler ball valve back into the grainfather. It was very easy to match the flow rate (with no grain in it). So I think the concept would work. But there would be no overflow safety mechanism on it, so you couldn't walk away from it. Plus, I don't know what kind of strain would be put on the pump.

In the end, I think it would be just as easy to do a mash and batch sparge like I always did. So that would be my recommendation. Like pocketmon, my efficiencies hovered around 70 - 75% with higher OG brews.

 

[Allenk]

I know this isn't what you are looking for but I just use lme/dme to increase gravity on my big beers on the grainfather. It's a simple way to go. If doing 4 gallon batch you can program an extended boil into the grainfather app

 

[IchLiebeBier]

I know this isn't what you are looking for but I just use lme/dme to increase gravity on my big beers on the grainfather. It's a simple way to go. If doing 4 gallon batch you can program an extended boil into the grainfather app

This would work, and lots of folks do it, but you should be careful with the mash bill. If you add more specialty grains to compensate for the dme/lme addition, which you'll add in the boil, you may end up a mash bill that has too much specialty grains in relation to base grains, and therefore may not have the diastatic power for full conversion. So just keep that in mind.