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

[Peter Smith]

re-circulation will help with clarity as well

You have to see this to believe it.......   clarity of wort via grain bed filtration can be stunning, not so sure this directly moves into clarity of final beer.   I can feel my mash tun calling may go home to make a beer.......

[Chris Coutts]

Haha, beats working!

I was a little disappointed last weekend when experimental vorlaufing through the grainbag. I had heard stories like yours, so expected clear wort, but even after 5x 500ml recirc's it was still cloudy. Could have been the grind I guess.

[Richard Rice]

Well, I just add a couple of litres of boiling water and it seems to do the trick.  Plus, we can sparge with this also!

[Chris Coutts]

True, true.

Thats the thing with brewing, so many different ways to do the same thing, love it!

[Peter Smith]

http://www.howtobrew.com/section3/chapter17-2.html

I think the 10gal coolers make a very well designed mash tun shape,  I do BIAB and get much better results with a deep fine grain bed (ie doing double batches), about to move to 10gal cooler.....

there is no reason why your bag in a pot method wont work just fine, its cheap and easy to start with, maybe add the false bottom later if you have a cake tin platform for now.....I use pot in pot see my photos

[Scott H]

Doesn't have to be a false bottom though a well designed manifold would also work. Personally I prefer using a tun. I went from BIAB to a chilli bin tun and have just upgraded to a 55L pot tun. I don't have a false bottom in it yet but plan on making a twin bazooka manifold instead.

[Chris Coutts]

Was thinking through braided hose or coipper manifold too... but you'll end up not able to extract the last x cm of wort. As soon as level drops below top of braid or manfold, it will suck in air, and stop... I think. Copper manifold might be slightly better, with slits cut on underside, but you'd need to ensure all joins were airtight, which would make it harder to remove and clean.

A bottom facing pickup would result in the smallest loss I think. And throw in a grainbag, and you can pull bag out and tip out very last drop!

All theoretical though, and I might be barking up the wrong tree :-)

[Scott H]

Tried this once with the quick fit PVC (push connect stuff) either the slits weren't big enough or not enough suction/draw out of the tun, as a positive though its works mint as a sparge arm sits on top of the grain and feeds the water onto the surface without disruption the bed.

And yes you do end up with dead space in the mash tun using a braid or bazooka.

[Peter Smith]

you dont want or need to get to the point where you have dry grains and suck air, there is no reason to do this,  keep the FLOW rate low and SLOW, you will get all the sugars you need.   BIAB is normally lift out and rinse if at all, sparge is normally low and slow until you get enough wort into kettle or the gravity falls to far and you are not extracting sugar at all...   most BIAB sparge is rinse not sparge in the classical sense,   don't get me wrong I am in this BIAB camp but you have to understand why you want to spend 20 mins recirc then 20mins sparging vs 20 mins rinsing....   see if you can watch someone who has a 3 vessel setup brew , you will pick up whats happening.    True sparge vs rinse takes longer hence why so many here say they cant be bothered...   I am yet to form this opinion.

In a situation where all the sugar is in the grain and the water around it is gravity 1.000   the sugar will have positive presure forcing it out of the high gravity wet grain towards the low gravity water, as in  BIAB as it approaches 1.065 there is less pressure... its hard to do high Grav BIAB... (not impossible you can batch sparge)   hence normal sparging introduces water at 1.000,  if the water rushes past the grains vs slowly passes it doesnt have time to extract the sugars, hence the need to keep the grain bed fluid and the sparge SLOW.

Palmer 

Most homebrewers use the rule of thumb of 1 quart per minute. If your extraction is low, i.e. less than 28 points/pound/gallon, you should try a lower flow rate. The best way to control your flow rate by using a ball valve or stopcock on the outflow.