# Whats The Biggest Biab Batch Possible?



## ekul (28/1/11)

Hi Everyone,
With uni coming up i may not have as much time to brew, so i'm thinking about buying a massive pot to do bigger batches. I currently do double batches with my 80L pot, but i was thinking a 140L pot or bigger. I nochill everything so if i could do a quadruple batch once a month or so that would be great. 

Will the limiting factor be the seams in the bag? Should a single, circular piece of voille be used? (Thisis what i do currently) 

I was also thinking that drilling holes in my 80L pot and lining that with a bag could be sweet, and then use a pulley system to pull it out. Where i live there is a block and tackle that is designed for dressing a beast, its rated at 5 ton. So whatever my bag weighs i'll be able to handle it.

I also have a really good burner, apparently its good enough to boil a 44 gallon drum with ease. When i bought it i got the big one so that i could upgrade to any size pot i wanted, i kned one day i'd get lazy enough that i'd want to do big batches.

So whats the biggest batch possible with biab? Also if you have pics that would be great, just cause i would like to see some massive biab systems.

And what do you think i can push out of a 140L pot? I know i could do 3 easy, but would 4 or 5 be possible?

thanks all


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## bignath (28/1/11)

Cool. Even though im a 3V brewer, i can't wait to see some of the responses you get......Have thought about adding to my flexibility by getting an urn and bag so i can automate things a little easier. I don't get into the whole 3v vs BIAB, but would be interested to ADD to my brewing techniques, and the idea of being able to do a huge one - well, who in their right mind wouldn't want to do that?

cheers,

Nath


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## warra48 (28/1/11)

Does it all have to be in one bag?

Can you use, say, 3 bags in the one pot? Would be easier to lift out and drain than one huge one.


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## Nick JD (28/1/11)

Uni student without time to brew?  

I've never done anything remotely that huge but have a feeling you might be reaching the edge of strength of the voile lifting out that much grain - a weakness or a tiny tear could end in a hot splashing disaster. Could you have a voile lined basket that took the weight?


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## ekul (28/1/11)

warra48 said:


> Does it all have to be in one bag?
> 
> Can you use, say, 3 bags in the one pot? Would be easier to lift out and drain than one huge one.




thats exactly the kind of thinking i'm looking for! Have you tried this? I wonder if that would work.


Nick- Lol, i work as well as go to uni. They have me on 6 days a week at the moment, and when uni starts i'll be working whenever i'm not at uni. So my free time is going to be limited. Even at the moment it would be great if i didn't spend my day off over the top of a big pot of boiling wort (Thats not to say that i don't like spending my day off day bent over a big boiling pot of wort!).


I'm surprised this topic hasn't been discussed before. I did a pretty extensive search and the biggest batch i found was a guy doing kits. 9 kits n kilos in a 44 gallon drum! But nothing for biab. I have the capacity to ferment 3 fermenters at once, so maybe the 140L pot and triple batches may be the go.


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## WarmBeer (28/1/11)

ekul said:


> Hi Everyone,
> With uni coming up i may not have as much time to brew, so i'm thinking about buying a massive pot to do bigger batches. I currently do double batches with my 80L pot, but i was thinking a 140L pot or bigger. I nochill everything so if i could do a quadruple batch once a month or so that would be great.


Did you ever think that maybe *23 litres of beer a week* is not healthy while also studying?

Not judging, just sayin...


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## husky (28/1/11)

lots of people to help you drink it at uni


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## manticle (28/1/11)

WarmBeer said:


> Did you ever think that maybe *23 litres of beer a week* is not healthy while also studying?



No. Never occurred to me.



Studying isn't very healthy though.


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## SpillsMostOfIt (28/1/11)

Think of swiss voile (or suva voile if you're a Lincraft shopper) in the same way you might think of a large poly tank. I have a 40,000 litre plastic rainwater tank that is more than strong enough to hold its full capacity of water. That is not because the plastic is hugely strong, but because the weight of the water and the force it exerts is spread over a large area of plastic. The same is true of a BIAB bag. I've lifted 15kg (dry weight) of grain in my single-stitched bag and done nearly one hundred brews in it over the years. There is not even the slightest hint of stress apparent.

Last year, I lined a basket press with swiss voile (and polyhessian) and compressed it and some fruit with an 8 tonne hydraulic press. Both fabrics exploded, but the 40x3mm steel strap I made the basket rings out of deformed as well. 

Does any of this mean that I could lift my car in my BIAB bag? No. But, I reckon I could lift my car with my BIAB bag.

In the really large batch situation, I might find some neutral-colour polyhessian to make an outer bag for the voile bag. Still sounds a bit unwieldy to me, though.

Mash in the 80litre and boil in the big pot? Change to a slightly more high-brow uni?


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## argon (28/1/11)

With an 80L pot i would expect you'd be able to do a triple batch (57L packaged) of something at around 1050OG with 15kg of grain. Just look at post boil dilution. With 140L you'd be able to do a quad (76L packaged) 1050OG with 20kg, but it'd be reasonably difficult to get the grain out easily.

I used to do double batches via BIAB in a 50L pot. But it got to be a bit of a pain lifting out the bag laden with alot of grain. I was brewing over gravity and then post boil dilution. Worked ok but i noted that the bigger my grain bill became (relative to pot size) the lower my efficiency would become. Eventually gets to a point where you can't do it with any reasonable efficiency at all.

I still do double batches in a 50L mash tun and 50L kettle with post boil dilution. But i no longer BIAB. The simplicity of my 3V system allows me to do just about any grain bill size/OG i want without worrying about my proportional relationship in the mash tun and my batch size. I also don't have to lift out 15+kg of wet grain in one go relying on the bag not to split.

For example, I have planned a triple batch (57L packaged) of bo pils with my efficiency at 75% and 1048OG i only need 12.1kg... but that's with a 22L post boil dilution. 

So anything can be done... you've just got to realise the limitations/issues of over gravity... no matter what process you employ


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## brett mccluskey (28/1/11)

WarmBeer said:


> Did you ever think that maybe *23 litres of beer a week* is not healthy while also studying?
> 
> Not judging, just sayin...


If he's an 'arts' student,it won't matter too much  .....What did the arts student say to the science student?.... "Would you like fries with that?"


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## Harry Volting (28/1/11)

Isn't it funny how the collective mind works with a little creative lubrication.
I've had 2 poorly constructed large bags fail with spectacular results. Both had seam failures because I tried to put too much grain in the one bag. History has shown that the best bags are mum-sewn bags.
Only successful large scale result was with 2 bags in the one vessel (keggle with a false bottom) larger bag designed to fit the volume of the keggle and smaller bag same diameter containing specialty grains placed inside the main bag on top of the base malt. What a hassle. Much less work to form a BIAB collective and brew in several smaller urns on the one day. (try putting a 3V system in the back of a Mazda 3. ) 
My tip would be to check the brew day location electrical supply and limit one urn per electrical circuit if you can. Go you good thing.
Harry


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## brett mccluskey (28/1/11)

Harry Volting said:


> Isn't it funny how the collective mind works with a little creative lubrication.
> I've had 2 poorly constructed large bags fail with spectacular results. Both had seam failures because I tried to put too much grain in the one bag. History has shown that the best bags are mum-sewn bags.
> Only successful large scale result was with 2 bags in the one vessel (keggle with a false bottom) larger bag designed to fit the volume of the keggle and smaller bag same diameter containing specialty grains placed inside the main bag on top of the base malt. What a hassle. Much less work to form a BIAB collective and brew in several smaller urns on the one day. (try putting a 3V system in the back of a Mazda 3. )
> My tip would be to check the brew day location electrical supply and limit one urn per electrical circuit if you can. Go you good thing.
> Harry


just curious as to what people are using to sew their bags with ie: cotton? :beer:


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## Harry Volting (28/1/11)

Open the Kimono...
My mum swears by (what looks to me) like a light fishing line so it's probably nylon.
My failed bags were sewn with cotton.
I've repaired burst seams with dental floss and the rest of the bag seams failed while the floss stayed in place.
I've spent more time than I care to admit playing with voil bags before I realised that there were others doing the same thing etc etc.
My 'best bag' is a Spotlight so-called-swiss-voil mum-sewn with nylon and a round base. 30 litre urn 3 hour brew 'day'. 
Hope this helps.
Harry


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## [email protected] (28/1/11)

I sew mine with 100% polyester thread


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## manticle (28/1/11)

ekul said:


> I'm surprised this topic hasn't been discussed before. I did a pretty extensive search and the biggest batch i found was a guy doing kits. 9 kits n kilos in a 44 gallon drum! But nothing for biab. I have the capacity to ferment 3 fermenters at once, so maybe the 140L pot and triple batches may be the go.



Pretty sure QLDKev is a BIABer and is setting himself up with a 100L+ system (120 or 140 boil pot from memory).


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## kymba (28/1/11)

the missus is half way through sewing up my new bag for my new 98L pot

like you i was scared to lift 3 or 4 batches of wet grain without reinforcement, so i chased down some 25mm wide polyester webbing and had her sew it around the sides of my new bag. all the lifting will be done via the webbing, so hopefully the voile holds out!?

the concept is like...





oh and i (get her to) sew the bag with poly thread used for making jeans. you need to use a leather needle to use this stuff as it pretty thick

cheers

kymba


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## Bizier (28/1/11)

I have done some triple batches of lower OG (say 1.040ish) beer BIAB in a 100L kettle. It is pushing it, but it can be done fine. The prick of a thing was that at the time, there was nothing to hang a hoist for my bag off.


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## Acasta (28/1/11)

Biab bags can be made from steel mesh pretty easy, i remember seeing a thread on it. Ill have a look.

Edit: yeah here it is. http://www.aussiehomebrewer.com/forum/inde...showtopic=49696

You could make a big one of these. May make it easier then a bag.


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## Goofinder (28/1/11)

Why does it need to be a bag? All BIAB is is a really thin mash where you take the grain out of the liquor rather than the liquor out of the grain as you would in a 3V system. 

You just need a way to lift the grain out (and lift all the grain out which is where swiss voille comes in handy). A bucket, pot, whatever lined with some swiss voille would do the job as then it's not the fabric/stitching/whatever taking the strain.


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## ekul (28/1/11)

WarmBeer said:


> Did you ever think that maybe *23 litres of beer a week* is not healthy while also studying?
> 
> Not judging, just sayin...



Lol. I don't drink 23 litres a beer a week. I like my beer to get lots of age on it. Plus my mates drink a fair bit of it.

My beer costs me around $4-5 a carton, this cost is offset by my time. So while taking a few cartons only costs me around $20, it also costs me a fair chunk of time. If i can make quaruple the amount of beer, in the same time that it takes me to makea single, then i have reduced my 'costs'.

Edited to add- there's heaps of replies now, thanks guys! Keep them coming, i'll read them after work.

Also, i'm a science student... So alcohol is an elective, rather than a core subject


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## Thirsty Boy (28/1/11)

If you want to stick with "a bag" then i think the bag reinforced with webbing (or even strips of voile folded on itself??) is the most elegant solution. That really keeps things exactly the same, just bigger and stronger. The strength of the bag concept is something you wouldn't be too fussed about if you have ever seen the "big bag" powder dispensing systems... They are like that, the main material with webbing providing lifting points/support and general reinforcing.

But the simplest and easiest to manage is probably to use multiple bags. A normal bag is fine for a double batch say 40L so two of them gives you a quadruple batch and thats about what you'll get out of your 140L pot without having to bugger about with sparging etc.

Multiple bags will make stirring harder, restrict the ability of the mash to flow, move etc - and you might well find that your efficiency suffers as a result, which happens a little bit as BIAB batches get bigger even with a single bag. So you could do a quadruple batch with two bags, and all it would really be is a little less efficient than it was before.

But logistics will kick in too - you'll need a way to lift the bags, get rid of the grain, heat the water, boil the wort - and twice as big means twice as much hot liquid, twice as much chance to cock something up and tip it over and much more disasterous results when you do. Not saying thats a reason not to go large - but its something you need to take into account before you just go as big as you can. Go too big and you will start to hit the limits of what you can easily and safely do with homemade gear - which is why the pros pay so much more for their stuff, scale matters - be aware and make sure you stay safe.


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## brett mccluskey (28/1/11)

Harry Volting said:


> Open the Kimono...
> My mum swears by (what looks to me) like a light fishing line so it's probably nylon.
> My failed bags were sewn with cotton.
> I've repaired burst seams with dental floss and the rest of the bag seams failed while the floss stayed in place.
> ...






Beer4U said:


> I sew mine with 100% polyester thread


I use 'fireline' or 'spiderwire' ...fishing braid to the uneducated  Fantastically strong,expensive though,easy to thread through a needle eye,and lasts forever ....


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## alkos (28/1/11)




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## kymba (28/1/11)

Thirsty Boy said:


> or even strips of voile folded on itself??



make sure you (or your missus) stitch it real fine if doing this, as the crushed grain finds its way into every nook & cranny

I had the missus make a bag 'doubled up' for strength and there are grain remnants from about a year and a half ago - but every brew adds to the next, it is like little pockets of flavour past

I shudder at the thought of what it is doing to my beers, but nobody has died of leftovergrainism yet, and the mates say everything is ok - mostly by rolling around on the ground and vomiting


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## Lecterfan (28/1/11)

toper1 said:


> I use 'fireline' or 'spiderwire' ...fishing braid to the uneducated  Fantastically strong,expensive though,easy to thread through a needle eye,and lasts forever ....



What an awesome way to combine two of the best things about each respective past time. Now if I could just brew on the beach when the salmon are on...


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## Mayor of Mildura (28/1/11)

alkos said:


>


holy crap. is that phillip? imagine the amount of hops that went into that!!!


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## Andyd (28/1/11)

If you're truely stuck on the idea of a single bag, then "double bag" it (i.e. make your bag from two layers of voile). That should improve its strength (unless something compromises the mesh, like, say a knife  ). 

But as Thursy points out, the logistics of a single big bag are not going to be pretty....

Andy


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## brett mccluskey (28/1/11)

Lecterfan said:


> What an awesome way to combine two of the best things about each respective past time. Now if I could just brew on the beach when the salmon are on...


i'm sure ,with the ingenuity of homebrewers ,it wouldn't be too much of an issue to sort out... :lol:


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## Nick JD (28/1/11)

I reckon what you needs are two vessels that fit inside each other. Drill out a bunch of holes in the bottom of the inside one and line it with voile. 

Drill 4 holes in the inside vessel's perimeter and install chains. 

When your mash is done hoist the inner vessel out, put a plate of plywood of the same diameter in and a few kgs of weight, let it drain, swing it out of the kettle's way and unclip three of the chains letting the grain tip out into a wheel barrow.


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## ekul (29/1/11)

Nick JD said:


> I reckon what you needs are two vessels that fit inside each other. Drill out a bunch of holes in the bottom of the inside one and line it with voile.
> 
> Drill 4 holes in the inside vessel's perimeter and install chains.
> 
> When your mash is done hoist the inner vessel out, put a plate of plywood of the same diameter in and a few kgs of weight, let it drain, swing it out of the kettle's way and unclip three of the chains letting the grain tip out into a wheel barrow.



I reckon this is the way to go so that sparging is possible. I see three options.

1) Use a 140L pot for the kettle, buy a 120L pot to fit in that and drill holes in the bottom. Would probably work really well, but it would be expensive, plus the 120L pot would never be able to be used for anything else.

2) Use a plastic inner vessel. Cut the top off a plastic 44 gallon drum, drill holes in the bottom and use that for the inside vessel. This means that you can sparge correctly by tipping in water. Obviously the material that the drum made from would have to be food grade.

3) Use a bag that has impermeable sides. A bag like this would be exactly the same as using a bag in a pot with holes in the bottom. The material that i think would work would be hdpe, like those woolworths green bags. Those bags cost around 10c to make so it shouldn't be too expensive to make one up. Making a bag with woven hdpe sides has the advantage that it can be exactly tailored to the kettle, as it can be made as large or small as you want. The sides will also add strength to the bag. So you could just lift the bag up and throw your sparge water on top.


Also, for lifting, i reckon the best thing would be a cheap hand winch, like this one. http://cgi.ebay.com.au/2000LB-RATCHET-HAND...=item2a0d3fff75
And also a pulley system. A quad batch of wet grain is going to be bloody heavy @ 30-40kgs!!


I know someone up here who has bought a 140L pot so i will check their's out. If i can find a source of that 'green bag' material for the right price then i think i will seriously consider making a massive biab rig. Even if i don't upgrade i may look at making a bag with impermeable sides for my double batch system. I think it would make sparging so much easier if i could just hopist the bag up a little and pour the watter in the top instead of f###cking around with plastic containers and pots of water.


The other thing i'm going to try next brew day is using two bags in my double batch system, just to see how it goes. I have a feeling its going to be a little frustrating, but it might be really good so we'll see.


thanks everyone for their input, there's some really good ideas here.


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## QldKev (30/1/11)

What about using a 82L keg for the internal pot? (no you can't have mine B) ) maybe visit Bunnings and look at the rubbish bins and other containers, I think you could get one a pretty good size. 

Then you could also get a march pump and recirc the wort back through the grain bed, and hopefully get an efficiency level that would mean no need to sparge. 

The other thing I though off is why do you need to lift the bag out with all the grain in it? Make a bag for the pot, and to remove the grain get a decent size scoop lined with swiss voile and scoop the grain out into a large sparge bucket (rubbish bin). The sparge bucket could also be lined with voile and have a tap on the bottom for draining the sweet wort. You could even do a cold water sparge.

Also I think another simple way could be a 2V BIAB system. Get 2 x 140L pots, line the first one with voile and mash. Drain the wort from the grain into the second pot for the boil. You could do a cold sparge into the mash pot. The good thing about this is if you feel like a big brew day you could always get a second mash in running in the first pot while you a boiling in the second pot. So for a bit over an hour extra you get 2 full batches. But you would need a second burner. 

When I get my pot maybe we should do a trip to the green shed.

QldKev


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## Zizzle (2/2/11)

Some locals here do 20 gallon batches no worries.


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## ekul (2/2/11)

thats awesome Zizzle. I do reclall seeing those pics before, nice one.


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## DanRayner (2/2/11)

When people speak of a BIAB system where there is, instead of a bag or supporting the bag, some kind of bucket with holes in the bottom - isn't that like the crazy German home brew system? With winches and pulleys? I can't remember what it's called but I know that at least one brew shop stocks it. Comes in a 50L model and a 200L model...


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## MHB (2/2/11)

As one of the people that sell them I will take exception to the term crazy and only the 200L Braumeister has a built in crane.
Braumeister
I have a 225 L stock pot and a forklift; I keep looking at them and thinking....... Hummmm
MHB


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## DanRayner (2/2/11)

MHB said:


> As one of the people that sell them I will take exception to the term crazy and only the 200L Braumeister has a built in crane.
> Braumeister
> I have a 225 L stock pot and a forklift; I keep looking at them and thinking....... Hummmm
> MHB



HA! Yeah.... I'm sure it's awesome but it is pretty bat-shit-crazy-looking  Have there been many people who've bought them?

hmmm.... yep, an electric pallet jack or forklift is all you'd need - then again, a second vessel and a pump might also do the same trick


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## speedie (2/2/11)

dan it takes all the fun out of a brewday if you cant drive a forklift


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## stux (2/2/11)

I can do triple batches 60L with my 50L pot

You should be able to do a quad batch with 80L fairly easily

The only real problem is lifting the bag. Lifting straps and a block and tackle seem the way to go. 

Look into Maxi-BIAB


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## DJR (2/2/11)

Engine hoist...


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## MHB (2/2/11)

DanRayner said:


> HA! Yeah.... I'm sure it's awesome but it is pretty bat-shit-crazy-looking  Have there been many people who've bought them?
> 
> hmmm.... yep, an electric pallet jack or forklift is all you'd need - then again, a second vessel and a pump might also do the same trick


The 50 L model is selling its arse off; right now we are waiting for production to catch up with demand. The 50 Braumeister model works so well with no-chill that its the model most people are settling on.
When the AUD was in the toilet they were costing about $5K for the 50 L model (thats what mine cost me) now at ~$4K they are seriously good value and Ive sold about a dozen in the last twelve months. I realise its not going to be everyones first choice and that $4K isnt cheap, but if youre looking for high-end semiautomatic systems its to my mind about the best value out there.
MHB


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## DanRayner (2/2/11)

speedie said:


> dan it takes all the fun out of a brewday if you cant drive a forklift



true, I should probably find an excuse to drive one around my garage brewery, maybe move my fridges around just for the hell of it?



DJR said:


> Engine hoist...



That is a seriously fucked-up looking BIAB bag!

 



MHB said:


> The 50 L model is selling its arse off; right now we are waiting for production to catch up with demand. The 50 Braumeister model works so well with no-chill that its the model most people are settling on.
> When the AUD was in the toilet they were costing about $5K for the 50 L model (thats what mine cost me) now at ~$4K they are seriously good value and Ive sold about a dozen in the last twelve months. I realise its not going to be everyones first choice and that $4K isnt cheap, but if youre looking for high-end semiautomatic systems its to my mind about the best value out there.
> MHB



Fantastic news Mark, glad to hear people are jumping in at the high-end! In other news, I sent a mate to your shop a few months ago; Al had just got back from OS (Switzerland), moved to Newcastle and was keen to set up - hope he's been in to get supplies...

cheers,

Dan


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## MHB (2/2/11)

If we are talking about a Geology lecture at UNc, then yes, him and his wife.
Mark


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## DanRayner (2/2/11)

Ah cool - he's a top bloke


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## geoffd (2/2/11)

Have just read the thread quickly so maybe this has already been covered, but have you got the adequate BTU's to get your superbatch to a rolling boil?

worse comes to worse I guess you could build a furnace outside with some bricks & boil on firewood, also need a steel plate to block flame if nearing a boil over. also I presume you have enough fermenters & long enough syphon for transfer or a tap on the pot.

just throuwing about some ideas, there is more to be thought through than the size of the pot. good luck (to tour liver) if you can do it


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## argon (2/2/11)

Stux said:


> I can do triple batches 60L with my 50L pot
> 
> You should be able to do a quad batch with 80L fairly easily
> 
> ...



So are you just doing a sparge and a big post boil top up then??

Used to do that with double batch BIAB in 50L... successful but a bit of a PITA


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## stux (2/2/11)

argon said:


> So are you just doing a sparge and a big post boil top up then??
> 
> Used to do that with double batch BIAB in 50L... successful but a bit of a PITA



Top up with sparge and water addition pre-boil

Top up as high as you can go with boiling water before end-of-boil/whirlpool, so you dilute kettle trub

Transfer to cubes

Dilute in fermenter to desired OG

I designed a spreadsheet to calculate it all, and help with the process, http://www.biabrewer.info/viewtopic.php?f=21&t=595

...

Its not that bad, because you don't actually have to measure anything just fill up as high as you dare to go at various points, and all that really matters is your initial fermenter gravity reading, then you dilute to OG.

Still working out how to calculate the IBUs properly 

...

As an example, 

I fill my 40x40 50L pot to 4cm for mash, 8cm for boil and 2cm for end-of-boil

13KG of Grain at 75% (I get 83-85% most of the time) should get me 57L of packaged beer (3 kegs)

L:G ratio would be 3.48:1

If I do get 75% efficiency, I would have

40L of liquor at start-of-boil at 1.075

if I get 80% efficiency it would be 1.080

...

End of boil I should have 48L of wort, at 1.063 for 75%, or 1.067 for 80%

I would transfer between 45 and 47L of wort

45L at 1.063 would be 60L in the fermeter at 1.048,

47L at 1.067 would be 65L


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## ekul (2/2/11)

Father Jack said:


> Have just read the thread quickly so maybe this has already been covered, but have you got the adequate BTU's to get your superbatch to a rolling boil?
> 
> worse comes to worse I guess you could build a furnace outside with some bricks & boil on firewood, also need a steel plate to block flame if nearing a boil over. also I presume you have enough fermenters & long enough syphon for transfer or a tap on the pot.
> 
> just throuwing about some ideas, there is more to be thought through than the size of the pot. good luck (to tour liver) if you can do it




Yep. When i first started biab i started with a single ring burner. This was a pita so i got a triple ring burner, this was barely better so i bought the biggest mongolian i could find, a 32 jet beast. It will boil a 44 gallond rum if i wanted to (which i do, just got to work out the rest  )


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## argon (2/2/11)

Stux said:


> Top up with sparge and water addition pre-boil
> 
> Top up as high as you can go with boiling water before end-of-boil/whirlpool, so you dilute kettle trub
> 
> ...



ahh nice one... :icon_cheers: i do double batches with a small top up post boil. Either into cube or into fermenter. My pre-boil is typically 41L for 34L into cubes... it's touch and go for the first 15mins or so watching for boilovers. I like the idea of topping up at the end of boil though. Something i think i might do now that i've bought myself a refractometer and can adjust on the fly a bit quicker.

Might do a triple batch (57L) Bo Pils soon... should be fun. I've worked that out to be a post boil top up of 22L


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## stux (2/2/11)

argon said:


> My pre-boil is typically 41L for 34L into cubes... it's touch and go for the first 15mins or so watching for boilovers



Yup, that's why I allow a different max volume for start of boil, compared to end of boil. It is touch and go with 41L in a 50L pot at the beginning, but by the end of the boil, it has settled down a lot, and my logic is, that a boiling water addition before the flameout/whirlpool can't really do any harm, and as long as you allow enough headspace for the whirlpool, you should be good.

Just for giggles I just worked out a 25KG batch into this 120L pot (55x49cm)

129L in the fermenter, L:G ratio of 4.28

Assuming 83% efficiency, target end of boil is 111L at 1.057

Into fermenter is 129L at 1.048

Which is not even pushing anything, except the ability to raise the wet grain without a calamity.

...

And, 

25KG of Base + 5KG of other = 30KG, which gives you L:G of 3:1 with 173L into the fermenter at 75% efficiency, time for a 200L fermenter


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## ekul (2/2/11)

I'm actualy thinking that it may be easier/cheaper to have a side by side system. So two pots instead of one big one. 

I already have 2 pots, one 67L one and an 80L one. The 67L one is JUST big enough for a double, if the grain bill isn't too big (coopers pale ale clone is perfect). I have a50L pot there too, so if i don't feel up to a quadruple i can still knock out a triple fairly easily

The heats sources here are a 32 jet mongolian and a 3 ring burner. Apparently if i drill out the jets on the 3 ring and put it on a high pressure reg it will boil a double batch easy, i know someone up here who has done that.

I'm thinking of getting an old hills hoist and reinforcing it with steel and whacking some pulleys on it, so i can move my bags around with ease. 

Either that or adding a bar above the brew stand with a roller. With the roller i could hoist the bag up, slide it to the left and dump it in the sparge bucket. This would make my brewstand less portable, unless i make it so it bolts together.

It all depends what i can find at the tip  MIght pop in there tomorrow.



EDITED TO ADD - Keep the ideas coming though guys, i'm enjoying reading them.


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## QldKev (2/2/11)

ekul said:


> I'm actualy thinking that it may be easier/cheaper to have a side by side system. So two pots instead of one big one.
> 
> I already have 2 pots, one 67L one and an 80L one. The 67L one is JUST big enough for a double, if the grain bill isn't too big (coopers pale ale clone is perfect). I have a50L pot there too, so if i don't feel up to a quadruple i can still knock out a triple fairly easily
> 
> ...



Come around Sunday, I'm thinking of trying a quad batch using 2 bags in the one pot.

QldKev


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## stux (2/2/11)

I boiled 40-45L the other day with a 2 ring burner on BeerBelly's Medium Pressure Variable Reg the other day...

That was for a double batch munich dunkel (OG 1.052)

I think it was 10-15 mins to get from mashout to violent boil.

Quite respectable.

I had taken to the burner with a 2.5mm drill bit to clean out all the holes, but not to actually increase the size of the bore.

My italian burner is on its way


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## nosco (28/6/16)

Reviving an old thread coz I saw this.

http://www.biabrewer.info/viewtopic.php?f=9&t=3578

?couldnt post the pic?


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## Danscraftbeer (28/6/16)

^ Since there is no follow up pics I suspect fail?

Oops it does link to more, my bad. Seems they finished the brew. I just don't like that raised thin sack of hot heavy mash etc.
Too scary and possibly messy. Ignore my anti biab remarks.... -_-


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## QldKev (29/6/16)

I did a couple of 112l batches in the 140l pot before finishing my 3v. Ekul enjoyed the big sized biab brewday and started it. He is still doing it to date.


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## Matplat (29/6/16)

I saw on brulosophy the dis a batch with a micro brewery who were doing either 200 or 500l batches with biab, I dare say the bags weren't made from swiss voile from spotlight....


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## yankinoz (29/6/16)

If I had a commercial brewery, I'd wish I could junk my lauter tun and go BIAB. Whatever the water to grain ratio, sparge or no-sparge, decoct or not, BIAB is the better design. Maybe with the advances in carbon and other fibres, one or more bags will be the rule in the biggest mashes.


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## Matplat (29/6/16)

You could split up the weight of a big mash by using nested bags (like russian dolls).... checked that exbmt on brulosophy, they were 2bbl (200l I think?) batches each done with a mega biab bag.


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