Grainfather: Reiterated Mash

[joegbeer]

Using beersmith to estimate results for a large RIS recipe to be brewed in a Grainfather system. However, I'm splitting the grain bill in half and doing back to back mashes. I've only done this twice now. After the first go around, I thought I had the process narrowed down where I could predict my results better in beersmith. Unfortunately my second attempt I was still significantly off on pre-boil gravity (1.09 instead of 1.102).

For normal single mash recipes I'm usually within a point or two. I played with the brewhouse efficiency settings AFTER brewing to get the prediction to match the results. I had to set the efficiency to 55%.

Any Grainfather users doing reiterated mashes? How are you predicting your results? Is there a better way for me to adjust setting in Beersmith?

 

[thehaze]

Your efficiency will suffer with a reiterated mash.

I also have a Grainfather and if I want to hit 1.100 I need to lower the batch size and / or use some sugar to boost the ABV. I got 1.096 with a 17.8 lbs grainbill and some sugar.

I never did a reiterated mash, as for me, it seemed unneccessary, if I could just cut the batch size from my normal 5.5-6 gallons to 4.5 gallons.

 

[joegbeer]

Your efficiency will suffer with a reiterated mash.

I'm aware of that.

I also have a Grainfather and if I want to hit 1.100 I need to lower the batch size and / or use some sugar to boost the ABV. I got 1.096 with a 17.8 lbs grainbill and some sugar.

I understand that I'm pushing the limits of the equipment. I've added DME in the past as one approach to hit higher gravity.

I never did a reiterated mash, as for me, it seemed unneccessary, if I could just cut the batch size from my normal 5.5-6 gallons to 4.5 gallons.

I've also used the approach of reducing my target batch size. However in order to hit the 11.5-12% ABV target for the RIS recipe, the output batch became so small 3.5-4 gallons so I could get all the grains in that the Grainfather water calculator would give me like 0.1 gallons of sparge water. Obviously, that wouldn't work very well.

Grainfather promotes the reiterated mash technique on their blog. I just thought I'd try a different technique and see how well i could adapt my process to using it.

Appreciate the suggestions.

 

[Smellyglove]

I just recently scaled a 1.112 OG for a "kit", and had to take into account the GF or other brew-system users. Bear in mind that I have never used a GF. I was looking into this mashing technique, but went away from it due to the results seemed unpredictable, unless you know how this works on your system good.

I went for a double mash, where both mashes were half the boil size and should yield about the preboil target gravity. I felt this was much controllable, in Beersmith atleast. Full batch size.

 

[murphyslaw]

Interested to know if OP ever ended up trying a reiterative mash?

 

[joegbeer]

Yes. When I posted above, I had done two sessions with reiterated mashing.

I'm trying to decide whether I want to continue doing reiterated mashes and try to get better at predicting the SG and overall efficiency. Or just add DME or sugars to boost a smaller grain bill. Not sure which is a better approach.

 

[murphyslaw]

Sorry, I do actually remember reading that because your 55% number stuck in my head. I watched a video by David Heath on youtube and he claimed to get 93%. I split the difference and planned for 75%. Unfortunately, I couldn't find my hydrometer. If my refractometer was right--and its probably not--I ended up with about 64% efficiency. I was shooting for 1.115 and ended up with 1.083.

I'm trying to fill a 10g whiskey barrel so I'm trying again tomorrow. I got a new hydrometer so I should get a better idea of how it goes.