Water and Grain Calculation Correct?

[TeflonTom]

I've gone ahead and decided to start putting together a few experimental recipes, however I've run into something for which I seek advice! I have calculated out that for my target OG of 1.068 I need 14.6lbs of my grains for a small 6 gallon test batch. My brewing system suggests 1.25qts water/lb of grain, but that would only be 4.5 gallons! Would that be correct and that I am to mash in such a small amount of strike water? In my past recipes I typically am mashing in 7 gallons just to reach 5.5 gallons at fermentation volume. Where am I going to get the rest of the water for my boil if I am to try and make a 6 gallon fermentation volume batch? Would I simply just sparge the grains until I reach 8 gallons to boil? Please help!

 

[VikeMan]

My brewing system suggests 1.25qts water/lb of grain, but that would only be 4.5 gallons! Would that be correct and that I am to mash in such a small amount of strike water? In my past recipes I typically am mashing in 7 gallons just to reach 5.5 gallons at fermentation volume.

1.25 qts/lb is a reasonable mash thickness. It's probably a little lower (thicker) than average, but it's fine, assuming you aren't using a mash tun that has a significant amount of volume at the bottom that the grains can't reach. But, what do you mean by "My brewing system suggests"?

Where am I going to get the rest of the water for my boil if I am to try and make a 6 gallon fermentation volume batch? Would I simply just sparge the grains until I reach 8 gallons to boil? Please help!

If you are not mashing with your total water volume, you have two basic choices...
- Sparge (fly sparge or batch sparge) with the remaining water
- add the remaining water to the mash, then lauter (i.e. do a "no sparge")

Which of the above are possible may depend on your equipment. And all else being equal, the choice will affect your mash efficiency, which in turn affects the amount of grains you'll need.

 

[TeflonTom]

1.25 qts/lb is a reasonable mash thickness. It's probably a little lower (thicker) than average, but it's fine, assuming you aren't using a mash tun that has a significant amount of volume at the bottom that the grains can't reach. But, what do you mean by "My brewing system suggests"?



If you are not mashing with your total water volume, you have two basic choices...
- Sparge (fly sparge or batch sparge) with the remaining water
- add the remaining water to the mash, then lauter (i.e. do a "no sparge")

Which of the above are possible may depend on your equipment. And all else being equal, the choice will affect your mash efficiency, which in turn affects the amount of grains you'll need.

I am brewing on a Ruby Street Fusion 15 Electric system and typically sparge my mashes no matter, but this is my first crafted recipe and just am not used to such a low volume of water. My mash tun has a nice false bottom and typically only has a quart loss when transferred to boil kettle. By "my brewing system suggests" that is what the efficiency of the manufacturers recommended. So what you are saying is that sparging would be the best way to complete the boil volume? I typically transfer at a rate of a quart per minute from mash to boil. My mash efficiency has been spot on for all previous brews I have done, but if I need to kick up the amount of grain just to increase the amount of water I have no problem ordering more grain.

 

[VikeMan]

I am brewing on a Ruby Street Fusion 15 Electric system and typically sparge my mashes no matter, but this is my first crafted recipe and just am not used to such a low volume of water.

So, mash with more water if you want, and deduct the increase from the water you would have added in the sparge or added to a "no-sparge" before lautering.

My mash tun has a nice false bottom and typically only has a quart loss when transferred to boil kettle. By "my brewing system suggests" that is what the efficiency of the manufacturers recommended.

The "efficiency" of the manufacturer of the Ruby Street Fusion 15 told you that you should use 1.25 quarts per gallon? Still doesn't make sense.

So what you are saying is that sparging would be the best way to complete the boil volume?

No, I'm not saying that. I said you could choose to batch sparge, fly sparge, or "no-sparge," depending on what your equipment supports. And that the choice would impact mash efficiency. A properly executed fly sparge will yield a higher mash efficiency than a batch sparge, which will yield a higher mash efficiency than a no-sparge.

My mash efficiency has been spot on for all previous brews I have done,

If you know your mash efficiency for previous batches, estimate the change in mash efficiency you might see with a larger (or smaller) grain bill, and adjust your grain bill again to accomodate the new expected mash efficiency. The bigger the grain bill, the lower the mash efficiency.

but if I need to kick up the amount of grain just to increase the amount of water I have no problem ordering more grain.

I did not suggest increasing the grains just to increase the amount of water. The amount of water you need is not a goal. It's a function of everything else. The total water you'll need is desired batch size into the fermenter + grain absorption + unrecoverable mash tun dead space + tun to kettle transfer losses + kettle hop/trub absorption + boil off + kettle to fermenter transfer losses.

 

[TeflonTom]

Okay I'm starting to understand. Thanks for the help! I'm still warming up to the more technical side of calculations and my systems efficiency so sorry if I sound green. I will recalculate for my mash absorption, dead space, and fly sparge. I will post updates once I get my ingredients and have a brew day!

 

[pvpeacock]

Don't get too hung up on grain to water ratios. I always use 5 to 5 1/2 gallons of water for every 5 gallon batch regardless of the amount of grains used. After the mash, I see how much wort I get when I drain my mash tun and then add enough sparge water to get my pre-boil volume. Unlike the mash, you should get 100% of your sparge water back. So, if you get 3 1/2 gallons of wort from your mash and want to boil 6 gallons, just add 2/12 gallons of sparge water.