Large dead space under false bottom

I bought a brewrite 10g pot with a false bottom. it takes over 2g of water just to bring the level above them false bottom. I've done a few AG batches with varying levels of success. I'm mashing in this pot right now. I do have another pot for sparge water. I do have an igloo, but I was was trying to do it all in one pot.

I'm just not sure how to factor that space in. If my recipe calls for 3g strike water then I need 5g in the kettle and then another 4+ to sparge.

Basically I'm starting with vary large amount into the boil kettle and a long boil.

I'm debating trying to modify the false bottom and use a dip tube.

I'd put in some sort of tube, attached to the bottom of the false bottom to get down in there farther and get that liquid out. I recently moved from a cooler MLT to a converted sanke, and I relocated my dome-shaped false bottom from the cooler to the keg. There was a ton of deadspace under the thing because of the shape of the bottom of the keg, so I just screwed a 1/2" female threaded copper fitting onto the bottom of the falsie, and it gets almost everything out now.

It was a $2 fix and required no tools.

I've often wondered about your question about the using 5 gallons instead of 3 for mashing in. In my setup i have about 1 gallon of liquid underneath my false bottom and i've never added extra, however a couple of times it felt like my mash was super thick, i would be curious to hear what works for you.

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martyphee said:

I bought a brewrite 10g pot with a false bottom. it takes over 2g of water just to bring the level above them false bottom. I've done a few AG batches with varying levels of success. I'm mashing in this pot right now. I do have another pot for sparge water. I do have an igloo, but I was was trying to do it all in one pot.

I'm just not sure how to factor that space in. If my recipe calls for 3g strike water then I need 5g in the kettle and then another 4+ to sparge.

Basically I'm starting with vary large amount into the boil kettle and a long boil.

I'm debating trying to modify the false bottom and use a dip tube.

Click to expand...

I have the same exact problem. I am fairly new to to this so you may not want to listen to me, but here is what I do:

First I know my total water for the mash and sparge say it 8 gallons. For simplicity sake say it works out to be 3 gallons for mash and 5 for sparge. With my 2 gallons underneath the false bottom that only leaves two gallons for actually in the grain which isn't enough, so I just bump up the mash 2 gallons.

So the mash for my equip is 4 gallons for mash and 4 gallons for sparge. But what I do is when I am draining the mash portion I aim to leave about 1.5 to 2 gallons in the pot, so I only collect 2 gallons. Then I add the sparge water. At that point there is about 6 gallons in the tun. It has been working for me very well. My efficiency has been between 80 to 89%. I also recirculate during the mash after about 30 min passes. I just open the spigot, drain about 2 gallons and pour it over the top of the grain, to get that water that sits below the grain actually into the grain.

I would also get a pick up tube as mentioned.

http://www.bargainfittings.com/index.php?route=product/product&path=46&product_id=93

That's the problem. The false bottom is almost 2" off the bottom and above the output port?

acslater55 said:

I have the same exact problem. I am fairly new to to this so you may not want to listen to me, but here is what I do:

First I know my total water for the mash and sparge say it 8 gallons. For simplicity sake say it works out to be 3 gallons for mash and 5 for sparge. With my 2 gallons underneath the false bottom that only leaves two gallons for actually in the grain which isn't enough, so I just bump up the mash 2 gallons.

So the mash for my equip is 4 gallons for mash and 4 gallons for sparge. But what I do is when I am draining the mash portion I aim to leave about 1.5 to 2 gallons in the pot, so I only collect 2 gallons. Then I add the sparge water. At that point there is about 6 gallons in the tun. It has been working for me very well. My efficiency has been between 80 to 89%. I also recirculate during the mash after about 30 min passes. I just open the spigot, drain about 2 gallons and pour it over the top of the grain, to get that water that sits below the grain actually into the grain.

I would also get a pick up tube as mentioned.

http://www.bargainfittings.com/index.php?route=product/product&path=46&product_id=93

Click to expand...

Since my port is below the false bottom the pickup won't help unless I modify the false bottom. Right now it sits almost 2" off the bottom.

I think I'll give your method a try. Thank you for the input. It was one of my thoughts earlier, but wanted to find out how others were coping with this.

martyphee said:

Since my port is below the false bottom the pickup won't help unless I modify the false bottom. Right now it sits almost 2" off the bottom.

I think I'll give your method a try. Thank you for the input. It was one of my thoughts earlier, but wanted to find out how others were coping with this.

Click to expand...

Wait...what? It sound like your setup is exactly like mine. The false bottom is above the port and the port is about 2" off the bottom. There are two problems it represents.

1. The is a lot of dead space under the FB that doesn't interact with the grain and throws off your mash water calculation. So we talked about that above.

2. With the port being high you will leave a lot of wort in the MT without something to get it out, so you will loose efficiency. I have measured my Megapot and it leaves about .75 gallons in the MT. That's a lot of wort. The link I gave you is a pick up tube to get as much of the wort out of the MT as you can. Now with my set up I get all but half a quart out. You should have plenty of room for a pick up under the false bottom.

Maybe you are thinking that the pick up goes vertical into the grain bed? It doesn't it faces downward to get all that nice wort you would otherwise leave.


ac

acslater55 said:

Wait...what? It sound like your setup is exactly like mine. The false bottom is above the port and the port is about 2" off the bottom. There are two problems it represents.

1. The is a lot of dead space under the FB that doesn't interact with the grain and throws off your mash water calculation. So we talked about that above.

2. With the port being high you will leave a lot of wort in the MT without something to get it out, so you will loose efficiency. I have measured my Megapot and it leaves about .75 gallons in the MT. That's a lot of wort. The link I gave you is a pick up tube to get as much of the wort out of the MT as you can. Now with my set up I get all but half a quart out. You should have plenty of room for a pick up under the false bottom.

Maybe you are thinking that the pick up goes vertical into the grain bed? It doesn't it faces downward to get all that nice wort you would otherwise leave.


ac

Click to expand...

Yes, they do sound exactly alike. I wasn't thinking a pickup tube would be worth it. Though I might give it a try. I should be able to make one pretty easy like the one he's selling. If I had other things to order from him I would just order one, but I've already spent enough...

Check out this drawing... Did I get the current configuration correct? If so, then I would recommend the setup to the right.

I'm certainly not an expert, but here's my thoughts.

- That much dead space below the FB will certainly water down the wort prior to boiling since you can't get that wort out - I think - (not an issue if you lower your efficiency to increase your grains required to hit your OG).

- You are correct that you'd need to figure out how much dead space there is below the FB (which you've already done, ~2 gallons) and add that quantity to your strike volume.

Example:
10 pound grain bill
1.5 quarts/pound water to grist ratio
- you'd need 15 quarts of water (3.75 gallons) for your mash plus 2 gallons for dead space = 5.75 gallons in your MLT.
- you'd need to know the grain absorption (assuming ~.20 gal/pound absorption rate). 10 pounds x .20 gallons/pound = 2 gallons (someone check my math please).
- you'd then need your sparge water too (assuming 6 gal boil volume). 5.75 gal strike water - 2 gal (dead space loss) - 2 gal (grain absorption loss) = 1.75 gal + sparge water needed = 6 gal (boil volume). Solve for sparge water needed, 6 gal - 1.75 gal = 4.75 gal of sparge water.

SO... 3.75 gal strike water + 2 gal dead space + 4.75 gal strike water = ~10.5 gal of total water needed... (I didn't account for shrinkage (it's cold outside) and loss to trub).

Other considerations.
Do you make water adjustments? - You'll need to account for the larger volume of water...
Do you recirculate your mash water? - This could increase your efficiency a little bit but you've still lost the wort below the FB.

Bottom line. It would be muy bueno if you could get the FB lower and use a dip tube. If nothing else it would save some money over the long haul because your efficiency would go up a bit. The other advantage is that you can make slightly larger beers if you recoup that lost space. Other than that, there really isn't a disadvantage of your current design.

my $0.02

Wow, exactly. Nice pictures. Visio? Lowering the FB would be good for larger batches. I just did a Dreadnaught and was at the pots limit with 17# (?). Had about <1" to spare.

The false bottom would be easy enough to lower. Just need to drill out some spot welds and add a hole/attachement for the dip tube. Just annoying having to modify an $85 FB.... How much space would be considered the minimum below the FB so as not to scorch the grain if I heat the pot?

Thank you for the suggestions!!

martyphee said:

Wow, exactly. Nice pictures. Visio?

Click to expand...

Actually, no, MS PowerPoint. I'm at work (shhh, don't tell) and only have PP.

martyphee said:

The false bottom would be easy enough to lower. Just need to drill out some spot welds and add a hole/attachement for the dip tube. Just annoying having to modify an $85 FB....

Click to expand...

Completely agree, but, most of us have to modify something that didn't fit quite right...

martyphee said:

How much space would be considered the minimum below the FB so as not to scorch the grain if I heat the pot?

Click to expand...

I am currently using a direct fire method (putting my MLT on one of the burners and recirculating the mash liquid from below the FB to the top of the mash) and have had reasonably good luck doing it that way. I bought my dip tube/FB combo from Midwest Supplies and still had to modify the setup due to the placement of my bulkhead fitting that was welded into my keggle. Anyway, the FB is about (guessing) 11" in diameter to the outside edge but tapers down to fit the bottom nicely. I'd guess that the FB sits about 1" off the bottom and the raised center portion is only about 9.5" in diameter.

I'd say that, depending on your heat source, you'd be good to go if you can reduce the space below the FB to 1" or so. That's a wild a$$ guess but should work well. Bottom line is that you want to have enough liquid to drain off the bottom and pump to the top such that it doesn't scorch (like you stated for concern). You won't be able to pump a huge volume quickly because the liquid should still be flowing down through the grain bed on its own (not being sucked through by the pump). I use one of the March brand pumps and throttle the flow back quite a bit. The result is that I've had to work on my techniques to not get huge temperature fluctuations. Basically, I turn my banjo burner on so the flames are just barely visible and leave it on for about 3-4 minutes and then shut it off. I typically do that about every 15 minutes. PITA? You betcha! No HERMS = manual effort.

The good thing about doing the recirculation method is that you set your grain bed (biggest benefit), you can increase efficiency a little bit (shouldn't be a concern for us homebrewers - that much) and you can see when you have good conversion (clear, not milky, on top but you still should test with iodine if you really care - which I don't do).

Last thing, I don't direct fire to reach sparge temps, I still do a mash-out infusion. Mash outs are optional but I still do it to stop additonal conversion.

Here's a picture of my FB so you can envision what I'm describing.

ThePearsonFam said:

The good thing about doing the recirculation method is that you set your grain bed (biggest benefit), you can increase efficiency a little bit (shouldn't be a concern for us homebrewers - that much) and you can see when you have good conversion (clear, not milky, on top but you still should test with iodine if you really care - which I don't do).

Click to expand...

going a little , but....

I don't think that the wort being clear indicates conversion. I use a HERMS system, and the recirculating wort is clear within 10 minutes of me starting the mash. I don't think it's converting that fast. It's just clearing up because the solids have been filtered out.

You're right, I don't mean that the wort is running clear, rather that the layer of wort on the top of the grain bed doesn't have that starchy/milky appearance when the conversion is nearing completion. I still mash for the entire time (60 to 90 minutes depending on the grains). Maybe I'm just simply wrong... I am still somewhat new compared to some of the more senior members here. I did get a bit off topic though.

EDIT

Here's my reference...

"After 45 minutes to one hour, determine visually that the conversion is complete by checking the clarity of any liquid resting above the mash bed. If your mash is a bit dry, you can create a small divot in the mash bed to get a puddle to form. If the liquid is clear, a complete conversion is near. If the liquid appears cloudy, you might want to wait a bit for additional clarification prior to further testing.

The iodine test is one way to determine whether there is any residual starch that lacks conversion. Just head to the local pharmacy and pick up a &#8220;tincture of iodine.&#8221; This is a small bottle that will last you about 10 years if you do not knock it over while performing the test."

Tafoya, A. (1999). Successful Mash Conversion: Tips from the Pros. Brew Your Own, The How-to Homebrew Beer Magazine, May. Retrieved from http://***********/stories/techniqu...successful-mash-conversion-tips-from-the-pros

Just got a 40 qt pot with a false bottom and having the same 2 gal space problem. Was wondering if I could just get some river rocks and fill up about an inch under the false bottom. Don't want to modify the bottom. That should bring the dead space to about 1 gal. Found those stones on ebay http://www.ebay.com/itm/30-lbs-Blac...444?pt=LH_DefaultDomain_0&hash=item53ebfdffe4

It says that they are aquarium safe and won't change the water chemistry. What do you guys think?

I have been struggling with this problem since beginning all grain. I have 3 25 gallon stainless steel pots (BK, MLT and HLT). My MLT has a false bottom with 2 gallons below it. I do not intend to modify the false bottom. My pickup is about 1 inch up so I can't get at the last 1.25 or so gallons of wort below the false bottom. BUT after sparging that liquid isn't all that strong anyway. Correct?

My solution to the pump pickup point was to add a 90 degree elbow fitting to allow all but the last .5 gallons to be pumped out of the MLT.

Now the bigger issue is what the MLT deadspace does to your boil volume and consequently your O.G. post boil. Adding an additional 2 gallons to your strike water is one part of the fix. BUT the rest is reducing your sparge water by 2 gallons to get your BK fluid level where it belongs. Not sure how much efficiency is lost by this change - but for me it is minimal as I do triple batches (15 gallons per run - so my strike water is usually 12.3 gallons and my sparge water is 14.5 with 33 pounds of grain). That is using 1.25qt per pound of strike water plus the 2 gallons deadspace and 0.5 gallons per pound of sparge water (fly sparging). My rig is also a HERMS system so my grain bed is set at mash end and my wort is prefiltered during about 15 minutes of the 60 minute mash (with HERMS pump in auto and temp set at 152 +/- 1 degree).

My last batch I hit an OG of 12.6 brix (1.051) which was spot on. My question is does all this make sense or did I bump my head too many times when I was younger????

Thanks!

Reading through this thread I think I am in the right one to post this question...I just hope you're all still around to answer since the last post is in 2012. Anyway here it goes....I just installed my false bottom mash tun kit with the 5/8 diptube from brewhardware.com on my converted keg. I have no pump yet so my draining method from the mash tun at this point will be just opening up the ball valve and letting gravity do the work. With that being said and doing my leak testing last night after it was all installed I let the water drain out through the ball valve and it initially was extremely slow and left a lot of water behind above the FB and I thought to myself "well that blows and will be leaving behind a ton of good wort". So I made some adjustments on the diptube and shaved some off the bottom and re-ran a drain test and that solved my slow trickling drain (it was pressed to far down and close to the bottom of the keg) however I'm still left with what appears to be roughly the same amount of liquid behind. Question 1: Is that normal???? And question 2: Will a pump solve this problem since I assume it will suck all it can through the diptube like a straw? Any help and input would be great. Thanks guys

Anything below the height of the hole in the side of the kettle won't drain unless there is some source pulling it up the length of the dip tube. A pump will do this, as well creating a siphon with tubing, where the "pull" of the water exciting through the tubing will "lift" the water up the dip tube.

exactly. If you did not have a hose attached to the output port hanging down from the thing, then the flow is going to stop as soon as the liquid level reaches the ball valve.

Thanks fellas! Did a you tube video on the install
[ame]https://www.youtube.com/watch?v=2vAFgDX9eGM[/ame]

I have the same problem. I am considering a way to remedy this as my batches are dwindling. This is me best solution: full the deadspace with some inert object. Perhaps glass marbles, small closed jars or some such item which would displace the room under the false bottom.

My concern with simply adding more water is that the temperature and amount of water to raise the math to the 168 mash out would be rather lacking.

Please let me know your thoughts.

MisterE said:

I have the same problem. I am considering a way to remedy this as my batches are dwindling. This is me best solution: full the deadspace with some inert object. Perhaps glass marbles, small closed jars or some such item which would displace the room under the false bottom.

My concern with simply adding more water is that the temperature and amount of water to raise the math to the 168 mash out would be rather lacking.

Please let me know your thoughts.

Click to expand...

Googled up this old thread wondering if I have a problem. Ordered a Stout 9 gallon MLT and 9.2 HLT.

Wasn't expecting this much space under the grain bed but it might not be a bad thing. As it has a good bit of volume to for starting a pump. It's less likely to scorch if I fire up the MLT RIMS burner.

I have about 1.25 gallons of space under my false bottom but it's got about 1/2-1qrt of true dead space. The side drain hole is about 1/4" off the true bottom.

It's got me thinking of my strike volume and dough in process. Specifically the calculation for the temp and thickness. It's not going to be that thick since 1.25-1.5 gal is under the false bottom. These are both direct fire models so undershooting the temp means I need to turn on a burner and a pump. I can do RIMS and HERMS with this set-up.

I'm not too worried about it, since I kinda do no-sparge step mashes with my old igloo mash tun. It's got me wondering what I haven't figured out for brew day. I guess I need to focus on the net volume.

I may have to do some practice runs without grain to see how this will heat up, heat transfer, pump transfer and otherwise drain off.

I was currently doing a vorlauf in a cooler with a pump. Now I'll have two pumps. One for the wort to do RIMS/HERM and the other for the recirculating the HLT. This is to even out the heat stratification.