BIAB bag vs false bottom... thoughts?

[Chris Coutts]

Hi,

Interested to hear people thoughts on the good ol' grainbag vs a false bottom. Just bought a new 50L pot for mashing, and was planning on making a false bottom like everyone else. But it's also tempting to stick with a big BIAB grainbag to sparge through, instead of the more expensive and tricky to make false bottom.

Grainbag + standoff pro's:

1. Cheap, easy to make
2. Can lift out at end of sparge to tip out all liquid

Cons:

1. Is there any downside as far as the beer is concerned?
2. Bit of a nuisance to clean I suppose

I tried this method last time, with 30L pot and using a burner for heat during mashout it was tricky not to let the liquid boil near the bottom. Does that happen with a false bottom too?

Sorry for the rambling, and cheers for any ideas!

Chris

[Crusader-Rob]

i RUN A biab SYSTEM, AND HAVE ACTUALLY BEEN THINKING ABOUT USING A FALSE BOTTOM AS WELL. INTERESTED IN THOUGHTS ON THIS. THE IDEA WOULD MAINLY BE TO KEEP BAG OFF THE BOTTOM WHEN HEATING TO MASHOUT TEMP.

[Bill Herbert]

I infuse mash in a cylindrical 50L chilly bin (cooler sounds cooler) using both a bag and a wire mesh cistern supply hose (rubber hose pulled out of course). I am sure everyone knows of this easy false bottom alternative. Def keeps the funk out of the wort. However, the mesh hose has on occasion snagged the mesh bag and tore it.

I just returned from the States and brought back a 30 cm false bottom from Northern Brewer in St Paul, Minnesota. Cost US $51.00 but they gave me 10%discount for being the longest distance customer of the year so far. I have failed to source a falsie in NZ for over a year now. NB don't ship international so use the NZ Post USA service out of Oregon if interested.

I will be playing with new bottom soon. I do believe the grain and false bottom will give the best mash and sparge, especially when I convert to a step mash keg, burner and recirc setup.

Beyond the above waffle (oh how I love waffles) I think the cost of replacing mesh bags over time, vs the one time cost of stainless, makes the economic case for getting the falsie.

RDHAHB

[Peter Smith]

Logically you would think that a well designed false bottom would allow a better flow through the entire grain bed while sparging.....   how would you extract the wort at bottom of bag?  through a mesh braid?

[Chris Coutts]

I've got a tap (with DIY side pickup for double-use as a kettle). My wife also found a round cake-tray-thing which is almost perfect for the 30L pot, which keeps the bag off the bottom. So draining is easy. Another pro is that if you lose suction in the pickup, you don't lose the last litre or so. Can just remove bag and pour out.

The more I think about it, the more sense it makes.

[Richard Rice]

I don't do anything that fancy.  My mash tun is my boil kettle!  My brother in law had the top portion of a keg leftover so drilled a bunch of holes in the bottom.  You lift the bag out, slide the tray underneath, then sparge directly over the grain and the tray and it all drains through. 

 

Although, technically, you don't "need" to sparge with BIAB - you typically add the full volume of water in the mash tun!  Definitely easier to clean!

[Ralph]

BIAB produces good beer. Only downside is that you lose some efficiency if you are trying to do bigger beers (like 7% and above).

Also if you want to do bigger than a 30L batch it can get heavy/hard to lift out.

I do 50L batches in my BIAB. I have a block and tackle from a rafter in my shed to lift the bag out of the pot with a rope grab to keep it lifted up. I heat the water, mash in the bag, lift the bag out and leave it draining over the kettle as I heat up and boil. By the time I am half way through the boil the bag is pretty well drained and I take it away. Is simple and works well. 

I just hose the grains out of the bag afterwards and pop the bag in the washing machine with a little sodium percarbonate... so pretty easy clean up too.

I was using a chilly bin mash tun and think I do better beers from BIAB...

[Chris Coutts]

Just to be clear here, I'm transitioning from BIAB to 2-vessel, to get better efficiencies through sparging and also able to recirculate to remove proteins, but trying to keep the costs down.

Wondering if there are any disadvantages to using the grainbag in place of the false bottom. To me the finer hole size and the shear number of holes in the grainbag should result in a better sparge...? Or am I missing something?

[Ralph]

Ah. You would still need some sort of false bottom to hold the bag off the bottom or you will not get the flow out the bottom of the bag... If you can overcome that I do not see why it would not work... but then you might as well use a standard false bottom.

The idea of the false bottom mash tun is that the grain bed acts as the filter if you have recirculation to vorlauf then the grain bed should do the filtration even better than BIAB.

[Chris Coutts]

Yeah, got the cake cooling tray thing for the 30L pot. Just gotta find a big one for the 50L. Keeps the bag off the bottom, so heat from the burner doesn't melt it during mashout. Cake tray = $10, false bottom = $60+. Hmmmm.

Haha, will prob still do false bottom, just at war inside about keeping the simplicity BIAB :-)

[Richard Rice]

What about using an old chilli bin.  No false bottom required - just a bazooka screen attached to a pipe/tap through the wall of the tin. I'll see if I can attach a photo...

[Chris Coutts]

I was going to, but found chillibins seemed to be ridiculously expensive!

And you can't add heat for mash-out... not that thats a showstopper or anything.

And false bottom efficiencies are higher that braided pipe I've heard.

Anyway, got the 50L pot now.

[Crusader-Rob]

I've always thought about 2 vessel, but abandoned the idea, as times gone on, with the time saved and the quality I'm making nowa days (35/50 at GKBF Comp in chch) I figured it wasn't worth the extra time and hassel/cost.

I've used chilli-bins as well, when i first started i figured that was the best way to do it, but it takes time and effort, and BIAB is waaaay easier.

But all in all, if going 2 vessel, stick with the bag and false botom as well. keeps the bag off the bottom and the grain bed setting will be nice, with the higher efficiency from sparging as well.

re-circulation will help with clarity as well. (Or so JoKing says) and don't forget the ability to step mash if needed.