False Bottoms and Batch Sparge

[kiblerjd]

This is sort of a two part post, one part question, one part technique.

First the question. I use a 10 gallon Rubbermaid cooler with a stainless dome type false bottom. I was wondering if anyone had ever had trouble with these as far as grain getting under them. When I used to fly sparge I never had this problem or maybe just didn't notice it because the flow rate was so low. Either way now it seems like I'm getting a lot of grain getting around the thing and it doesn't stop. Even after significant recirculation I still get a little bit of grain and I would expect it to completely stop. (I recirculate with a pump until it gets clear for my vorlauf).

Second the technique. Maybe most of you batch spargers already do this and I'm behind the times but I changed my process a bit today and it worked really well. I'm always a little above 80% efficiency when I do 10 gallon batches and closer to 70% when I do 5 gallon batches. I have always had a hunch that this due to the fact that with 10 gallon batches I have to batch sparge twice due to the volume of water.

So today I did a 5 gallon batch and was looking to get about 7 gallons in the fermenter. Instead of adding all the sparge water at once I split it into two batches and I got 84% efficiency. Figured I would post this hoping it might help someone some day.

 

[iijakii]

First off, good deducing -- it's common to do two batch sparges regardless of volume for efficiency. As for the grain, maybe try cutting some silicone hose and wrapping it around the edge of the FB. Creates a better seal.

 

[kiblerjd]

I'm an idiot. There are dozens of threads talking about the false bottom issue. No need for any responses on that one seems to be pretty well covered. I like daytrippr's fix.

 

[hophop]

Double sparge is the way to go.


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[dmashl]

always double sparge and always hit my numbers. I also use a SS braid for my filter.

 

[cank]

I'm an idiot. There are dozens of threads talking about the false bottom issue. No need for any responses on that one seems to be pretty well covered. I like daytrippr's fix.

... Link!!!

I've been looking but...

 

[Sbarnard80]

Double sparge is the way to go.


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When you say double sparge, are you recirculating the whole first batch sparge or are you splitting the batch sparge amount in 2 and doing twice with half the water? Thanks.

 

[kiblerjd]

Twice with half the water.

 

[kiblerjd]

... Link!!!

https://www.homebrewtalk.com/f51/fb-gasket-10g-rubbermader-mlt-381111/

 

[BansheeRider]

Twice with half the water.

I get between 80-90% efficiency with a single batch sparge. Maybe I will try double sparging, but that takes more time since you have to heat up the sparge water twice. Do you heat up all the sparge water at once then poor half into the mash tun, drain, then poor the other half?

The grains get through my FB as well but only at the end of the draining. That last second of suction tends to suck up grain.

 

[kiblerjd]

I heat up all the water and put it in my HLT. I drain the mash to the kettle then add half the sparge water to the mash. I recirc until it's clear then drain it to kettle. I then repeat the process with the remaining sparge water. If you are getting 80-90% already I wouldn't even bother if I were you.

 

[dcbc]

I got some cord stock and laid it around the top outer edge of my false bottom. I didn't even bother securing it. It stays in place and I don't have any grain getting through any longer. Easy to remove and clean, too. Good cheap fix. The silicone hose would have made the FB too hard to get in place.

 

[kiblerjd]

Don't suppose you have a pic

 

[BansheeRider]

I heat up all the water and put it in my HLT. I drain the mash to the kettle then add half the sparge water to the mash. I recirc until it's clear then drain it to kettle. I then repeat the process with the remaining sparge water. If you are getting 80-90% already I wouldn't even bother if I were you.

Yeah maybe I'll stick to my process. Although sometimes beersmith says to drain then sparge in two steps. I have a 5 gal kettle that I use to heat up my sparge and sometimes the recommended sparge volume is over 5 gallons. To fix this I started using a 1.5qt/per pound water to grain ratio rather than sparging in two steps.

 

[dcbc]

Don't suppose you have a pic

Not at the moment. I bought a bit more than I need and just cut it to fit. Lay it around the edge and dough in. I was worried it might move around with stirring the mash, but it doesn't.

 

[kiblerjd]

I went out and took a close look at my mash tun and false bottom today and realized one potential cause may be that the hose connecting outlet of the cooler to the false bottom was like 1/8" too long. So it wasn't perfectly centered. Might be the cause might not be. With the thing centered there is zero place for grain to fit around it.

This got me thinking that another cheap fix may be to use copper or stainless tube instead of a flexible hose. I'm thinking of switching from barbed fitting to flare compression fittings and put a piece of tubing between the two. This will allow a nice ridged install but will also allow me to easily remove the false bottom for cleaning. Pretty sure this is the way that I'm going to go. Being able to remove my false bottom is a must for me for cleaning purposes. If this doesn't work I'm going with the cord stock. If the cord stock is cheap I may just try that first.

 

[dcbc]

Just checked my records. I used 3/8" cord stock. It's about $5 for 10 feet (before shipping).

http://www.zorotools.com/g/Rubber%20Cord%20Stock/00116997/

 

[kiblerjd]

I got some really good deals on a few swagelock fittings and some stainless tubing so i'm going to give that a try. I'll post some pics when i'm done. If i do it right it will be really difficult for that false bottom to ever move. If it does move i'm going to order the oring stock.

I also took some time to really carefully drill out the cross pieces in my CPC quick disconnects so even if some grain sneaks by it will not clog the fittings. I think these two thing combined will solve my issues.

 

[kiblerjd]

I'm super happy with this fix. The stainless tube is slightly bent to make up the difference in height from the false bottom to the outlet. It puts a tiny bit of tension on the bulkhead fitting that pushes the false bottom onto the bottom of the cooler. This thing doesn't budge anymore and I checked everything including the bulkhead for leaks. Works great so far now I can't wait to brew and really test it out.

 

[kiblerjd]

Brewed today I I think this made a pretty big difference but still wasn't perfect. I don't know how the grain is getting under that false bottom but it is. I recirculate with a pump and I'm wondering if it is strong enough to pull the grain right under it. I did back off on the flow today. Either way I'm happy but I wouldn't necessarily tell everyone to run out and do this. I think the cord stock is probably a better option but I have never used it. I may try both some day but I'm happy for now.


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[dcbc]

Considering the amount of room you have between your false bottom and the edge of the cooler, I'd suggest skipping the cord stock and buying some 3/8" silicone hose. Slice it down one side and slide it around the edge of the false bottom. The cord stock works in my setup because my false bottom goes right up to the edge of the kettle. On yours, it would make too big of a difference, I suspect.

 

[KTRyan]

First try this style false bottom:
http://www.homebrewing.org/12-Stainless-Steel-Domed-False-Bottom_p_1058.html

There better made with a better seal around the edge to stop grain from getting underneath.

Also for anyone using false bottoms, I stole a page from Blickmann and ordered one of these:
http://www.mcmaster.com/#9421t7/=qrfzgy

316 SS shaft collar, to be used on a SS dip tube with a 90 degree bend. I will warn the the shaft collar only works in the downward end of the dip tube is long enough.

 

[kiblerjd]

First try this style false bottom:
http://www.homebrewing.org/12-Stainless-Steel-Domed-False-Bottom_p_1058.html

There better made with a better seal around the edge to stop grain from getting underneath.

I may have to call this company and ask them a few questions or maybe you know the answers. I have a Rubbermaid cooler and I had to bend my connection hose to make it connect. These look like they are shallower and don't require any bending. I don't know if you have ever used one in a cooler before so that may be hard to answer. My question for you is have you ever used the other style of 12" false bottom before? I'm wondering if these have better flow through them and if they are heavier duty or anything. Just trying to see if they are worth spending the money because quite frankly they look awesome. Thanks for the info. I don't have the disposable income I used to or I would have ordered this thing last night to try it out.

 

[MrNatural]

Considering the amount of room you have between your false bottom and the edge of the cooler, I'd suggest skipping the cord stock and buying some 3/8" silicone hose. Slice it down one side and slide it around the edge of the false bottom. The cord stock works in my setup because my false bottom goes right up to the edge of the kettle. On yours, it would make too big of a difference, I suspect.

+1 for silicone. Comes in any size you need and good to 428F. I'm using it for edging on keggle rim.
http://www.ebay.com/itm/5-FEET-4-mm...r_Truck_Parts_Accessories&hash=item2580c77893

 

[Flboy]

Back to sparging, I batch sparge twice, and if the grain still is sweet, I dump it in a bowl with warm water and run thru a strainer until it isn't sweet, or I am at the max for my boil.

 

[KTRyan]

I've used the same kind of false bottom your using, and they use to drive me nuts. Just like you I thought I solved my problem by hard piping, still no good. Switched the the slotted style and was amazed by the difference. In the hand it feels much more substantial, I'm not sure if its actually a heavier gauge steel or if the design makes it feel like it is. With the style your using the rim of the disk has a lot of partial holes, which makes an imperfect seal even worse. The slotted design (as you can see in my picture) has a smooth rim, which makes a better seal. The flow rate you can achieve is better than the older style, however if your using a pump don't go full throttle, no matter how good your filtering mechanism is you can still compact your grain bed.

With your setup, I'm assuming, you have an elbow with a compression fitting on one end and a nipple on the other. The nipple side goes through the hole in the false bottom and it looks like your using the lock nut that came with your false bottom. Instead of bending the SS tube you should be able to tighten down that lock nut which should put pressure on the false bottom, pinning it in place.