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Help Stepping Up to AG

Hello Everyone,

I am a long time reader and first time poster who is looking to step up to AG Batch Sparge Brewing. I’d like to make NB’s Hope & King Pro Series 5 Gallon Kit as my first batch and have (more than) a few questions. My hope is that some of you will be good enough to leave some comments on the process I’ve concocted, which I’ve mapped out as follows:

My Calculations:

Recipe Grains = 12.0625 (I just added everything up in the recipe)

Strike Water = 3.75 gallons (1.24qt/lb x 12.0625 lbs = 15 quarts/4 = 3.75 gallons)

Process (gratefully adapted from DennyBrew.com):

  1. Mash in, shooting for & adjusting to 151 degrees for 60 minutes (per the recipe)

  2. Since this is my first time brewing AG, I do not know my grain absorption rate. If I lose a gallon or so per 10lbs of grain, that would put me at around 2.75 gallons of runoff, which would put me a little under my desired 3.25 gallons from my first runnings, if I am aiming for a pre-boil volume of 6.5 gallons.

Should I add an additional .75 - 1 gallon of water at the end of the mash, stirring and adjusting the temperature of the infusion water to bring the overall temp to 168 or so? Would doing so yield approx. the 3.25 gallons of first runnings I’m looking for?

  1. Recirculate

  2. Once clear, drain to kettle

  3. Drain quickly & completely

  4. Heat 3.5 gallons of sparge water to appropriate temperature to raise grain bed to 168

  5. Add sparge water, stirring thoroughly

  6. Recirculate and drain once again

  7. Proceed as usual with boil, etc.

Thanks and sorry for such a long post!

Keep it simple the first time. Don’t worry about adding extra water at the end of the mash. Just measure how much you get from the mash (that will also give you an idea of your absorption) and subtract that from how much you want to boil. The answer you get will be how much sparge water to use. You don’t have to drain quickly, but you can drain as quickly as your system allows. Quick draining is a benefit, not a requirement. Heat your sparge water to around 185-190 and then check the grain bed temp after you add it. Next time, you can heat a little more or less if you need to. Being off a few degrees is no big deal. Take careful notes, don’t freak out. You might want to read through www.dennybrew.com before you brew.

[quote=“Dan S”]2. Since this is my first time brewing AG, I do not know my grain absorption rate.

Should I add an additional .75 - 1 gallon of water at the end of the mash, stirring and adjusting the temperature of the infusion water to bring the overall temp to 168 or so? Would doing so yield approx. the 3.25 gallons of first runnings I’m looking for?[/quote]
Grain absorption is very nearly constant at ~0.12 gal/lb. So with 12 lb of grist you’ll leave about 1.5 gal behind in the grain, plus any dead space in your lauter tun. You can measure dead space ahead of time by putting a couple gallons of water in the tun, draining it as you normally would, then pouring out what’s left into a measuring cup. If you’re using Denny’s braid setup, your dead space should be small.

Given that, I would mash in with 4.75 gal, which should yield your 3.25 gal of first runnings. Then sparge with the remaining 3.25 gal. You may want to heat up a little extra sparge water just in case. Then, like Denny said, you can determine how much you actually need based on the actual first runnings volume.

Don’t worry too much about getting the grain bed to 168°F. When batch sparging, a mashout isn’t really all that important.

Make sure you start heating the sparge water shortly after the beginning of the mash so that it’s up to ~185°F by the time you need it.

Thanks to you both!

Your advise will be put to good use…

Back again with a follow up question about how much water to use in relation to the amount of grain for mashing.

I read in another post that Denny said he saw better efficiency if he used 1.6 - 1.75 qt./lb. of grain for the mash rather than 1.25.

If this is so, and if I increase my intended pre-boil volume to 7 gallons (I stumbled onto an online calculator that said I could expect 1.5 gallons of boil off with my 17" diameter pot, and I’d like to put 5.5 gallons into primary), would I want to mash in according to the following calculations:

Mash: 1.65 qt. H2O x 12.1 lbs. grain = 5 gallons
Grain Absorption: 0.12 gallons H2O x 12.1 lbs. grain = 1.5 gallons
Dead Space = TBD (still need to buy a cooler!)

Total = 6.5 gallons (+ dead space) needed to achieve 3.5 gal. of 1st Runnings (1/2 my pre-boil volume)

This would be an increase of +/- 1.75 gallons from what a10t2 suggested, which seems like a big jump, which is why I’m asking.

Thanks again for any suggestions…

Hope you all don’t mind if I give myself a bump up!

I’d be very interested to read any insights on why one would choose to mash at 1.25 qt./lb. as opposed to, say, 1.6 qt./lb.

Because 1.25-1.5 qt/lb is what a lot of books say to use and it works just fine. But I find that a thinner mash works better for me.

As Denny said, keep it simple. I batch sparge, following Denny’s methods and this is what I do with great success:

From experience, I lose 2g between evaporation and BK dead space. If I want 5g in the fermenter, I start preboil with 7g. From there is simple:

Mash water = 3.5g + grain absorption + MT dead space
Sparge water = 3.5g

I go with 0.125g/lb for grain absorption and my MT dead space is 0.12g so:

Mash water = 3.5 + (0.125 * 12.1) + 0.12 = 5.1325g
That equates to a grist ratio of 1.7qt/lb.

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