False bottom and added water?

[HOPCousin]

I read that I need to add extra water up to the bottom of the false bottom. Should I be adding extra grain for that water in order to hit my appropriate gravity?

 

[Catt22]

I read that I need to add extra water up to the bottom of the false bottom. Should I be adding extra grain for that water in order to hit my appropriate gravity?

Much depends on your system configuration, sparge method, MT volume etc. I have a 10 gallon MT with a full FB. There's about a 1 gallon volume below the FB. I am running a direct fired RIMS. The wort is continuously circulated during the mash, including that below the FB. My water to grain ratio is typically between 1.2 & 1.5 quarts per pound and I do not add any additional water or grain to offset the volume below the FB. All of the liquid is in play due to the circulation. So long as the grain bed is completely saturated you are good to go. A few minutes after dough in and stirring, the grain bed should be well saturated. As the starches dissolve, the grain bed will settle a bit and the mash will thin some. You can accomplish much the same effect manually vorlaughing occasionally during the mash. Experience with your setup will give you a much better feel for this.

 

[RoadKing]

The water below your false bottom doesn't count towards your Quarts per pound ratio.
I have 2 gallons below mine. I usually fill to that level then figure 1.3 Qts. per Lb on top.

 

[Catt22]

The water below your false bottom doesn't count towards your Quarts per pound ratio.

It does with my system. All of the liquid is circulated and in play for the entire duration of the mash.

 

[RoadKing]

It does with my system. All of the liquid is circulated and in play for the entire duration of the mash.

I do RIMS too, but being the foundation water isin't in constant contact with the mash, I don't add it towards the ratio..I figure it at 1.3. But when formulating recipes with Beer Smith I add it in there. So for an average 18-20 LB Batch, it comes to something like 1.67 Qt Per Lb. Then my strike and other water addions formulas come out correct.

 

[Catt22]

I do RIMS too, but being the foundation water isin't in constant contact with the mash, I don't add it towards the ratio..I figure it at 1.3. But when formulating recipes with Beer Smith I add it in there. So for an average 18-20 LB Batch, it comes to something like 1.67 Qt Per Lb. Then my strike and other water addions formulas come out correct.

But the foundation water is in constant contact with the mash when circulating continuously as I do. The enzymes are in the wort as well as the grist. I base the strike water volume on 1.2 - 1.5 qts/lb and that strike water is my foundation water as well. I heat the water in the MT before adding the grain and ususally hit pretty dead on the strike temp I'm after. The only additional water is for the fly sparge. I don't bother to caulate a precise sparge water volume. I just use what I need to reach my pre-boil volume and any left over is used for cleanup. Long ago when first brewing with my system I did add the extra gallon of strike water, but when I did so, the mash was always thinner than I wanted so I stopped doing it.

 

[HOPCousin]

I thought i would follow up and share about my experience with the false bottom. It's about a gallon that remains below the bottom. Went ahead and did my usual 1.25 qt/pd and found that my efficiency dropped by .007 with the new system. I'm assuming this was because not as much water was above and in contact with the mash. Planning on adding additional base malt to compensate and see how it goes.

 

[dutchoven]

I would assume that if you're using a dip-tube, all of the water is "in play". The sugars in the grain should distribute themselves throughout the total volume of water -- especially if you vorlauf or recirculate. However, if you're not using a dip-tube, thus leaving water in the tun, I'm not sure what the consensus is. I could see upping water and grain to account for the water/wort left behind, but then again, maybe not.

 

[audger]

i use HERMS and recirculate throughout the mash, and i do water calculations without considering the false bottom or the water volume in the hoses. all of the water gets circulated and comes into contact with grain regularly, so the water space below the false bottom is going to act the exact same as the water space above the grain bed. you dont change your numbers to account for the amount of water above the grain bed, do you?

so if i have 10lb of grain and am going for 1.25qt/lb, thats (3 and 1/8) gallons.

 

[PintoBean]

I found that I have 7 quarts under my false bottom, so I always add that to my 1.25qt/lb ratio. I do not recirculate, so it doesn't count towards the ratio. I found this out when I read "Designing Great Beers"\

Of course, you don't want to add 7 qts to the entire amount of water required for the recipe, so I subtract the 7qts from my sparge water.

 

[OneHoppyGuy]

I thought i would follow up and share about my experience with the false bottom. It's about a gallon that remains below the bottom. Went ahead and did my usual 1.25 qt/pd and found that my efficiency dropped by .007 with the new system. I'm assuming this was because not as much water was above and in contact with the mash. Planning on adding additional base malt to compensate and see how it goes.

.007? geez

 

[HOPCousin]

Yeah I calculated over the last 2 batches that my efficiency is now 63%. So the false bottom does effect efficiency in my case. It's really nice having the false bottom, spigot and temp on the mash tun though. I'm building my recipes based on this new efficiency now.