Intial dough in water anount for HERMS

[BentProp]

I have a HERMS system made out of 15.5 gallon kegs. The mash tun liquid is pumped into 50' of 1/2" copper tubing in the HLT then returned to the mash tun. I am using beer smith to help calculate the dough in water amount and it does not sound right. Basically I will be have approx 18 lbs of grain to mash for a 12 gallon final boil. Beer Smith suggests I start with approximately 5.5 gal water, then batch sparg with 2.7 gal then 6.7 gallons. As this is my first try using this set up, 5.5 gallons does not seem like enough water to dough in and then pump. Any help would be great.

 

[rollinred]

I am no expert by any means but that seems close. At the lower end but close. I guess following the rule of 1.25-1.5 qts per pound of grain your looking at 5.6-6.75 gallons of water for mash.

 

[Henrythe9th]

Thin it as you wish, I use 1.5 to 1.9qts per lb. usually get 5 to 6 gals off the first running 20 to 25lb grain
when recirculating you need a thinner mash

 

[BentProp]

OK, I just was not sure how much liquid I would need to get the recirculation going. Trial and error I guess. Thanks

 

[BentProp]

Like Colombo just one more thing! The total volume of liquid for dough in and sparg is around 14.9 gallons. In a trail run I had very little liquid (2 cups) remaining the mash tun after draining. I would like to end up with 12 gallons in the boil kettle. Is the grain (60 minute mash) plus evaporation join to absorb up 2.9 gallons of liquid? Thanks

 

[JuanMoore]

Grain absorption varies some depending on crush, etc, but most software figures ~0.1 gal/pound, or 1.8 gal in your case. Don't forget to also add your mash-tun dead-space to that figure, which beersmith doesn't do unless you input it into the system. Evaporation is another thing that varies depending on BK dimensions and how vigorous you boil, and you'll need to figure out what it is for you through trial and error. Between 1 and 1.5 gal/hour is probably a good place to start for boil-off. I'm guessing beersmith assumes 1.8 gal of grain absorption and 1.1 gal of boil-off, which is probably pretty close, but it's always best to prepare more brewing water than needed to make sure you hit your pre-boil volume. I usually prepare at least an extra gallon, but since you don't know your system yet I'd suggest preparing even more.

 

[BentProp]

Beer Smith defines - Lauter Tun Deadspace - (The amount of deadspace in the lauter tun, usually below the lautering screen. Represents the amount of water that will be lost when lautering grains.) I have read other definitions that say it is the amount of water absorbed by grains plus the amount of liquid from the bottom of the Mash tun to the filter screen. (This could be as high as 3.5 gallons) I currently understand it to be - the amount of water left over in the bottom the mash tun after the sparg is complete. In my case I have about 1/4 gallon which includes the hoses ect. I am definitely a little confused regarding this definition.

 

[JuanMoore]

Dead space and grain absorption are two different things, but they are often discussed together since they are both losses that need to be added up and accounted for. Input the amount that is left in the tun after draining for deadspace. Beersmith will calculate the estimated grain absorption based on how much grain is in the recipe.

 

[BentProp]

Hey thanks lot,

 

[Yooper]

I use 1.33-1.5 quarts per pound in my HERMS. I was using 1.25 quarts per pound (which worked fine, too) but I'm finding that ramping up with a quicker recirculation for mash out is smoother with 1.33-1.5 quarts per pound of grain.

I also like to have plenty of sparge runnings, and I found that no more than 1.5 quarts per pound gives me a good amount of sparge water to help keep my efficiency where I want it.