My first step infusion mash, are my amounts right?

[JSGT09]

I'm making a Wit this weekend and it calls for a 2 step infusion mash which I have never done before. Here is what I'm planning on, based on some online calculators:

11.75 lbs of grain @ 65 degrees

Step 1: Infuse 3.53 gal of 131.5 °F water for target of 122 °F, hold for 15 min
Step 2: Infuse 2.28 gal of 212.0 °F water for target of 154 °F, hold for remaining
Sparge: 4.07 gal of water

Total water: 9.88 gal
Initial mash thickness was 1.2 qt/lb and I ended up at 2 qt/lb after step 2

I had a hard time figuring out how much sparge water to use, but I just took my total water needed (based on a simple mash/sparge calculator) and backed out the multi step mash water used, which gave me about 4 gal of water needed for sparge. Does that sound right? Should I mash thicker?

PS...technically it calls for elevating from 122 to 154 over a time span of 15 minutes, but I'm using a cooler and don't have the luxury of slowing raising the temp.

 

[TrubHead]

I'm not able to do the computations right now but 2 qts/lb would probably dilute the enzymes too much. I suggest reading up on decoction mashing.

 

[T-Dan]

that is the way i usually step mash, but I aim for .8 gt/gal in the first step. that means less strike water in that step, at a higher temp. then your amount of water may vary slightly in step 2 (sacc rest), but you will have more available for the sparge. and your thickness will be more like 1.5 qt/gal. (can't do the cals for you right now, but that is the theory).

 

[JSGT09]

Here is what I end up with at .8 qt/lb:

11.75 lbs of grain @ 65 degrees

Step 1: Infuse 2.35 gal of 136.3 °F water for target of 122 °F, hold for 15 min
Step 2: Infuse 1.63 gal of 212.0 °F water for target of 154 °F, hold for remaining
Sparge: 5.9 gal of water

Total water: 9.88 gal
Initial mash thickness .8 qt/lb and I ended up at 1.35 qt/lb after step 2

Seems like a lot of sparge water?

 

[DSmith]

Here is what I end up with at .8 qt/lb:

11.75 lbs of grain @ 65 degrees

Step 1: Infuse 2.35 gal of 136.3 °F water for target of 122 °F, hold for 15 min
Step 2: Infuse 1.63 gal of 212.0 °F water for target of 154 °F, hold for remaining
Sparge: 5.9 gal of water

Total water: 9.88 gal
Initial mash thickness .8 qt/lb and I ended up at 1.35 qt/lb after step 2

Seems like a lot of sparge water?

I ran your #'s through ProMash Mash Designer and got the same as what you listed. I've step mashed from 110F->152F once, mashed in around .77 qt/lb and needed more water than the calculators predicted. Boil 2x the amount of water you think you need, the heat put into extra water will be used in the sparge. Also check your mash tun volume that you have room to put some extra water in if needed.

The (actual, not planned) final mash thickness was 2.0 qt/lb and had no issue with conversion - checked with iodine/caulk test. The planned mash thickness after the step infusion was 1.6 qt/lb.

 

[TrubHead]

Here is what I end up with at .8 qt/lb:

11.75 lbs of grain @ 65 degrees

Step 1: Infuse 2.35 gal of 136.3 °F water for target of 122 °F, hold for 15 min
Step 2: Infuse 1.63 gal of 212.0 °F water for target of 154 °F, hold for remaining
Sparge: 5.9 gal of water

Total water: 9.88 gal
Initial mash thickness .8 qt/lb and I ended up at 1.35 qt/lb after step 2

Seems like a lot of sparge water?

1.35 qt/lb is in the range for saccharification rest whereas 2 qt/lb could dilute the enzymes too much at this step.

I'm making a Wit this weekend and it calls for a 2 step infusion mash which I have never done before. Here is what I'm planning on, based on some online calculators:

11.75 lbs of grain @ 65 degrees

Step 1: Infuse 3.53 gal of 131.5 °F water for target of 122 °F, hold for 15 min
Step 2: Infuse 2.28 gal of 212.0 °F water for target of 154 °F, hold for remaining
Sparge: 4.07 gal of water

Total water: 9.88 gal
Initial mash thickness was 1.2 qt/lb and I ended up at 2 qt/lb after step 2

I had a hard time figuring out how much sparge water to use, but I just took my total water needed (based on a simple mash/sparge calculator) and backed out the multi step mash water used, which gave me about 4 gal of water needed for sparge. Does that sound right? Should I mash thicker?

PS...technically it calls for elevating from 122 to 154 over a time span of 15 minutes, but I'm using a cooler and don't have the luxury of slowing raising the temp.

 

[T-Dan]

are you making a 5 gallon batch? The 9.88 gals water sounds like a lot to me for less than 12 lbs of grain. I would assume about 1.5 gallons lost to the grain, which leaves you with about 8.38 pre-boil.

so if you reduce the total water, the sparge water becomes more in line....

 

[JSGT09]

5.5 gallon batch is planned, will boil for 90 minutes so I'm assuming my calculator is taking evaporation into account. It's saying that I should end up with around 7.2 gal of pre boil wort.