Biab Question

[reviled]

Hey guys, ive been looking into BIAB and at this stage the only thing holding me back is a sufficiently sized pot or kettle... So what I was wondering, is it possible to do BIAB in say a 15 litre pot, and then when mashing and boiling is finished simply water down the wort to final volume as you would with extracts? Or is this a big no no?

Cheers

 

[Thirsty Boy]

Its not a big no no - its just not as easy as it sounds.

You still have to include as much grain as you would if you were making a full sized batch, and then your gravity is higher, so your BiaB mash is going to be significantly less efficient, so actually, a bit more grain..

Fitting it in the pot becomes a serious issue. My BiaB pot is only 16L and I use it for small experimental batches. I tried to work out whether I could do just what you suggest, and for anything other than really quite low gravity beers, the answer is no I'm afraid

eg:

Lets make a bitter. If you were brewing the full volume - You want a finished volume of 19L (lets assume you will keg it) and you want an alcohol of around 4% so a starting gravity of about 1.040. Lets say you will lose only 1L to yeast in the fermentor. So you need 20L @ 1.040. Here's the bit you need to remember. 20L @ 1.040 is 20 x 40 = 800 gravity point. So to dilute your wort down to 20l@ 1.040, whatever you make in the BiaB has to also work out to 800 gravity points.

Now, your pot is only 15L, so your mash volume has to be less than that. So given that you will probably need about 4ish kg of grain, the most water you will be able to use is - 15 - 0.67 x 4 = 12.3L, lets say 12.0 o that its not right at the brim. So thats one of your limits, only 12L of water. Which once you pull out the grain bag, will most likely leave you with around 9.5L of wort. That wort will need to be boiled for an hour, and you will most likely lose at least 15% to evaporation, so your post boil volume will be about 9.5 - 0.15 x 9.5 = 8.1, lets say 8.0. You will lose at least a litre of that to trub ... same amount of break material from 4kg of grain no matter what the boil size... so you end up with 7L that you can put in your fermentor. Which to get 800 gravity points out of, needs to be at a gravity of 800/7 = 1.14.

So now we know what we are shooting for - finished wort @ 1.14. 8L post boil volume. Lets make a recipe.

65% efficiency assumed
5.45kg of grain (mixed Pale and some crystal etc)
11.3L of strike water
mash volume = 14.94L
Pre-boil = 9.41L @ 1.119 (you will have to add a little water as the grains will most likely absorb too much, even if you squeeze the hell out of them)
Post boil = 8L @ 1.14
puts 7L @ 1.14 into your fermentor. Dilute to 20L @ 1.040

And to be truthful... you would be extremely unlikely to get 65% efficiency with a gravity that high, more likely to be in the 50's - which pretty much makes it impossible to do. And thats just with a 1.40 target gravity.

You could do it if you "dunk sparge" and thusly increase all you possible post mash volumes, but you will need another pot. Even then, its not going to be practical for anything more than quite low gravity beers. here is also a limit to how "concentrated" you can make a wort before it starts to really effect the flavour of the finished beer - I suspect that this level of concentration crosses that limit.

With my 16L pot, using dunk sparge action, I can make 15ish L of "normal" beer without too much hassle, much more than that and you are asking for trouble.

One of BiaB's limitations, you only need the one pot, but it has to be a biggun I'm afraid.

You could try a "big" partial mash. All your specialties and a chunk of your base malt in the BiaB, and top it up to gravity with extract. Thats probably your best bet if you are not willing to settle for a smaller batch.

Cheers

Thirsty

 

[reviled]

Its not a big no no - its just not as easy as it sounds.

You still have to include as much grain as you would if you were making a full sized batch, and then your gravity is higher, so your BiaB mash is going to be significantly less efficient, so actually, a bit more grain..

Fitting it in the pot becomes a serious issue. My BiaB pot is only 16L and I use it for small experimental batches. I tried to work out whether I could do just what you suggest, and for anything other than really quite low gravity beers, the answer is no I'm afraid

eg:

Lets make a bitter. If you were brewing the full volume - You want a finished volume of 19L (lets assume you will keg it) and you want an alcohol of around 4% so a starting gravity of about 1.040. Lets say you will lose only 1L to yeast in the fermentor. So you need 20L @ 1.040. Here's the bit you need to remember. 20L @ 1.040 is 20 x 40 = 800 gravity point. So to dilute your wort down to 20l@ 1.040, whatever you make in the BiaB has to also work out to 800 gravity points.

Now, your pot is only 15L, so your mash volume has to be less than that. So given that you will probably need about 4ish kg of grain, the most water you will be able to use is - 15 - 0.67 x 4 = 12.3L, lets say 12.0 o that its not right at the brim. So thats one of your limits, only 12L of water. Which once you pull out the grain bag, will most likely leave you with around 9.5L of wort. That wort will need to be boiled for an hour, and you will most likely lose at least 15% to evaporation, so your post boil volume will be about 9.5 - 0.15 x 9.5 = 8.1, lets say 8.0. You will lose at least a litre of that to trub ... same amount of break material from 4kg of grain no matter what the boil size... so you end up with 7L that you can put in your fermentor. Which to get 800 gravity points out of, needs to be at a gravity of 800/7 = 1.14.

So now we know what we are shooting for - finished wort @ 1.14. 8L post boil volume. Lets make a recipe.

65% efficiency assumed
5.45kg of grain (mixed Pale and some crystal etc)
11.3L of strike water
mash volume = 14.94L
Pre-boil = 9.41L @ 1.119 (you will have to add a little water as the grains will most likely absorb too much, even if you squeeze the hell out of them)
Post boil = 8L @ 1.14
puts 7L @ 1.14 into your fermentor. Dilute to 20L @ 1.040

And to be truthful... you would be extremely unlikely to get 65% efficiency with a gravity that high, more likely to be in the 50's - which pretty much makes it impossible to do. And thats just with a 1.40 target gravity.

You could do it if you "dunk sparge" and thusly increase all you possible post mash volumes, but you will need another pot. Even then, its not going to be practical for anything more than quite low gravity beers. here is also a limit to how "concentrated" you can make a wort before it starts to really effect the flavour of the finished beer - I suspect that this level of concentration crosses that limit.

With my 16L pot, using dunk sparge action, I can make 15ish L of "normal" beer without too much hassle, much more than that and you are asking for trouble.

One of BiaB's limitations, you only need the one pot, but it has to be a biggun I'm afraid.

You could try a "big" partial mash. All your specialties and a chunk of your base malt in the BiaB, and top it up to gravity with extract. Thats probably your best bet if you are not willing to settle for a smaller batch.

Cheers

Thirsty

Cheers for all the info mate, I must admit im a little confused, so I just went out and brought a 35 litre stock pot

New toys consist of the said pot, a digital thermometer, a large pillow case size straining bag from the lhbs, 5kg golden promise grain, 1 kg marris otter grain, 2kg smoked malt, 2kg Munich, 1kg Vienna, and some various other specialty grains... This is all starting to get exciting :lol:

I dont have a burner, but a mate can give me a 2 ring gas burner, which should hopefully be big enough? Im planning on doing final volume batchs of between 19 and 23 litres, so im not sure, this is all new to me...

Also, if im going for a final volume of say 20 litres, how do I know how much water to start off with? How did you work that out? Sorry if the answers in plain black and white...

Im also getting hooked up with a free copper chiller :beerbang: But was thinking of getting a couple of cubes as well...

 

[Thirsty Boy]

Cheers for all the info mate, I must admit im a little confused, so I just went out and brought a 35 litre stock pot

New toys consist of the said pot, a digital thermometer, a large pillow case size straining bag from the lhbs, 5kg golden promise grain, 1 kg marris otter grain, 2kg smoked malt, 2kg Munich, 1kg Vienna, and some various other specialty grains... This is all starting to get exciting :lol:

I dont have a burner, but a mate can give me a 2 ring gas burner, which should hopefully be big enough? Im planning on doing final volume batchs of between 19 and 23 litres, so im not sure, this is all new to me...

Also, if im going for a final volume of say 20 litres, how do I know how much water to start off with? How did you work that out? Sorry if the answers in plain black and white...

Im also getting hooked up with a free copper chiller :beerbang: But was thinking of getting a couple of cubes as well...

35 is still pretty small. You will just fit a normal 5% ish strength beer in there, but for a stronger beer you will struggle and have to do a concentrated boil.

Will your pot fit inside your Pillowcase sized straining bag?? If not, the bag's not really big enough, and I have no idea whether it is a suitable material or not.... what is it designed to strain? Whats it made out of?

You work out the water (and this is the short version because I suspect I have answered this question at least 5 times in the past. Search function for details and the "why" of things) like this

Your desired post boil volume + the volume you boil off + the amount of water absorbed by the grain.

Your post boil volume will be the amount you want in your fermentor plus about 3L which you will leave behind because it will have all the break material and hops trub etc in it. So for your 20L finished volume .... it will be about 24L (1L extra lost to yeast in the fermentor)

Your boil off rate will depend on a lot of things, Your pot size and shape, your burner, how long you boil etc etc. You really have to take a guess for your first couple of brews and then dial it in. Or you can do a test boil with about 30L of water. See how much boils off in an hour. if you are using a two ring burner, it will probably barely manage to boil the required volume hard enough (if at all) so lets say you will boil off a quite low 10% ish or around 3L per hour. So 3L is the amount. BTW, you might be able to manage this on your kitchen stove if the pot will go across 2 burners... but your wife will hate you for it.

Your grain absorption will be around 0.75L for every kg of grain. So for the recipe you quote (ie about 5kg of grain) you will lose 3.75L of water.

This gives you - - - 24 + 3 + 3.75 = 30.75L of water to start with. Once you know your actual boil off rate you can tweak the figures a bit.

When you drop 5kg of grain into the 30.75L of water, you are going to have a total mash volume of - 0.66 X grain weight + starting water = 0.66 x 5 + 30.75 = 34.05L total mash volume. So it just fits in your pot.

Which tells you your limits almost straight away - the biggest beer you can make a 20L batch of, will have a grain bill of no more than 5kg. Any stronger than that and you will either have to make a stronger wort and dilute (which as described in my previous post, isn't as simple as it sounds if you need to do it more than a little bit) or drop your batch size.

Some of the questions you are asking and the things you have done so far - suggest to me that you might not have completely read PP's guide on how to BiaB. I suggest that you do. And maybe the pictorial I posted on the BN might help. You will find links to both on the BiaBrewer website. They might go a way to answering some of your questions.

Also, have a read of John Palmers How to Brew which you can look at online for free. This will give you a bit of basic mashing knowledge. A fair bit of it isn't directly applicable to BiaB, but then again, a fair bit of it is.

Otherwise, I'm going to ruthlessly push PP's new site a bit and suggest that you submit him some questions... that will help him to build up a comprehensive FAQ and save future BiaBers going through the Q&A process you are having to endure.

Cheers

Thirsty

 

[reviled]

Hey Thirsty

Cheers for the reply mate, I really appreciate it, I have read through the BIAB guide as well as your post on the BN, I found it all really helpfull but I just had some trouble understanding it all, you have made it alot clearer for me Sorry if im being a pain...

In regards to the pot size, im on a very restrictive budget due to having a 3 month old baby and a wife not working at the mo, so 35 litres was the biggest I can afford at the moment, so im prepared to make sacrifices in regards to batch size and my ending strength, I just really wanted to get into AG/BIAB asap as I was starting to really notice the extract "twang" after tasting my mates AG beers...

In regards to the straining bag, its a grain straining bag made out of voile material, desinged to strain grain, and the pot fits inside the bag, its huge, cost me $21.95, the lhbs gets them in from the UK and I just got it to save me on making one up myself (im no seamstress)

So correct me if im wrong here, but im well sorted (apart from the small burner, I would do it on the kitchen stove but we dont have gas, only those crappy flat top elements) for making 20 litre 5% batches of AG?

 

[FNQ Bunyip]

Great work Thirsty , your continued help of the new brewers is great buddy ...

You deserve a brewers recognition award of some sort ...

I suggest that some of these new brewers send you a couple of there best .

Your a bloody asset to Biab , AG and AHB ...

Cheers

 

[reviled]

Great work Thirsty , your continued help of the new brewers is great buddy ...

You deserve a brewers recognition award of some sort ...

I suggest that some of these new brewers send you a couple of there best .

Your a bloody asset to Biab , AG and AHB ...

Cheers

I definately second that :beerbang: I would not have made the BIAB jump without all of the helpfull info

I wonder if I can send beer from NZ to Aussie?

 

[Thirsty Boy]

I definately second that :beerbang: I would not have made the BIAB jump without all of the helpfull info

I wonder if I can send beer from NZ to Aussie?

Thanks, its my pleasure.

Tell you what... Instead of beer (although you can send some if you really want ) I'll settle for the details of the LHBS where you bought that grain bag. So many people seem to have a problem either finding the right material or finding someone to sew it up for them... it would be great to be able to point them at a place where they can buy them ready made.

You do sound as though you are set to go. And reading the thread where you made a general enquirey about your two ring burner, it sounds like it will most likely be fine as well. I'm sorry I sort of assumed you hadn't done your homework, its just that a few of your decisions had been on the edge of whats workable, and they looked like they might be just "hasty" ones - whereas it turns out that you have been pretty damn thorough in your research and have chosen the best compromise you could between whats practical and whats economical. You've done pretty well I reckon.

Now, stop talking and start brewing. Take that recipe of yours, throw 30ish litres of water in that pot and turn some malt into beer. It will be good beer. Trust me, it will. The rest just comes along with experience. You'll work it out as you go.

Have fun

Thirsty

 

[Bribie G]

If you want a bigger pot, have a look around wherever Chinatown is in Auckland and check out the Chinese, Korean and Filipino stores where they often have massive stockpots at good prices. The sort of thing you would never see in Kmart Target whatever. Judging from Motorway Patrol you seem to have a couple of Asian migrants there :lol: I recently bought a 15l pot just for messing around with extract and hop flowers boils but they had far bigger ones.

I paid the magnificent sum of $11 for mine, I work in Chinatown Bris. and will have a stroll out this arv and see what current prices are - should be similar in NZ one would imagine.

For a big pot of course forget the stove, my curly elements struggle with a pathetic five or six litres. Need a two or four ring burner (my next move B) )

Cheers

Michael

 

[braufrau]

Tell you what... Instead of beer (although you can send some if you really want ) I'll settle for the details of the LHBS where you bought that grain bag. So many people seem to have a problem either finding the right material or finding someone to sew it up for them... it would be great to be able to point them at a place where they can buy them ready made.

Why doesn't Ross sell them??? Ross??
Maybe I'll go into business next year making custom BIAB bags. (Is that like pin number??)

Wont have much else to do. I wonder what people would pay for one including postage?

 

[reviled]

Hey guys, update... My first BIAB/AG yesterday, most of it went really well with only a few hiccups along the way...

1st off, details on the straining bag, Here, $21.95, it worked perfectly for my size pot, I dont have a wire cake stand thing yet so what I did was roll the bag a bit so that it was about 8cm from the bottom of the pot, then tied it to the outside of the pot with some rope, put the bags of grain in there before I put water in to make sure it would hold the weight.. The bag held the weight of the grain well when I was draining the bag into a bucket, so all was good!!!

So heres how my day went...

Mash : I used my smoked porter recipe from Here had about 28 litres of water in the pot, brought the temp up to 67 degrees, added the grain and the temp dropped to 66, so I put the lid on, covered it in blankets and left it for an hour. Checked the temp after an hour and it had dropped to 63, so I brought it back up to 65 and mashed another 30 mins...

The strain/boil : Stirred the crap out of the grain, lifted the bag up, squeezed the hell out of it and put it in a bucket, I was really surprised at how much I could get out of the bag, I was just topping up the kettle every so often with a litre or so that I managed to get out of squeezing the bag, and just kept coming back to it, in the end I dont think I lost that much water to the grain by persisting with it... Probably the only reason I was able to be so patient was that my 2 ring burner took an hour to bring the wort to the boil <_< So ive asked for a 3 ring for fathers day haha

Boiled the wort for 70 mins with hop additions, it smelt fantastic, a distinct smoky smell, let it sit for 15 mins after the boil then proceeded to siphon the wort into a sanitised cube...

This is where I went wrong, not having used a siphon before I didnt think, and managed to melt the bottom of the siphon just slightly :unsure: But enough so that it doesnt work any more, so some of the wort was oxidised, and in the end I had to transfer it with a jug...

And then came the second problem, after I squeezed out the air in the cube and put it on its side, wort started going everywhere... The cube I got for some reason or another does not have a water/air tight lid So I put it back on its feet and stored it away to cool, but theres about 3-4 litres of head space there...

So ive got a couple of questions, not so much in regards to the BIAB process which I found excessively easy and straight forward, I remember stressing thinking "what have I got myself into", but afterwards feeling a massive boost in confidence for my next batch! I dont think I will ever go back to extract...

Anyway, my questions about my wort...

1. With the siphon melting slightly, do you think a small portion of plastic would have gone into the wort?
2. If the wort is likely to not be affected by the siphon, should I go and buy another fermenter asap so theres much less risk of the wort oxidising and going off? (due to the cube not being air tight)

Sorry for the mega long post, unless you cant tell my day was pretty epic, but in a good way...

 

[FNQ Bunyip]

congratulations buddy , all sounds good ... get that wort into a fermenter this morning and some yeast on it and all will be fine ...

Way back when PP melted an auto siphon " took one for the team " its mentioned somewhere back in the biab thread ....

cheers

 

[reviled]

Cheers mate, I just went and got another fermenter so will pitch when I get home from work :icon_cheers:

Just been thinking about this cube I have, I would (in theory) only need to find a better lid in order to get it air/water tight right?

Went and got a new auto siphon too <_< lol

Wonder if anyone else in NZ has done BIAB yet?

 

[Thirsty Boy]

maybe just a little food grade lubricant on the seal ??

Congratulations. Welcome to AG

Thirsty

PS - thanks for the link

 

[reviled]

maybe just a little food grade lubricant on the seal ??

Congratulations. Welcome to AG

Thirsty

PS - thanks for the link

No worries buddy, thanks for your help, couldnt have done it without your assistance...

 

[reviled]

Man, ive gotta say, I love this BIAB thing aye...

I punched out another batch last night, an APA with 4kg Golden Promise and 200 grams Crystal malt.

The best thing about it, is I got home at 3:30pm, got the mash down, while I was waiting for the mash to finish cooked dinner to keep SWYMBO happy cos she doesnt like me brewing around dinner time <_<

Got it all finished up and in the cube just before 8pm B) Pretty good effort I reckon considering I managed to cook dinner and juggle a 3 month old... lol

Used the following hop additions so im hoping it will have a fair whack of IBU's

60 mins : 30grams Cascade
30 mins : 18 grams Nelson Sauvin
15 mins : 25 grams Williamette
5 mins : 10 grams Nelson Sauvin, 15 grams Amarillo
Flame out : 15 grams Amarillo

 

[Online Brewing Supplies]

Im happy to say we have some BIAB bags being made up right now.We had PP do the design so we have a bag strong enough, seam taped and tag's :super: .They should be ready in a week or so.Patch's even convinced me into supplying a lot more BiaB related gear.More on that later .
GB

 

[chug!chug!]

How did you prevent melting the syphon the second time????
Just let the wort cool longer??

 

[wambesi]

Im happy to say we have some BIAB bags being made up right now.We had PP do the design so we have a bag strong enough, seam taped and tag's :super: .They should be ready in a week or so.Patch's even convinced me into supplying a lot more BiaB related gear.More on that later .
GB

That sounds great, especially for those who can't be bothered/know how/know someone who can sew it up for them.
I'll be keeping an eye on it, maybe I should upgrade my dodgy bag as it was made up of leftover materials as I cut some of the swiss voile out for filtering cold-brewed coffee and ginger beer plants, doh!

 

[reviled]

How did you prevent melting the syphon the second time????
Just let the wort cool longer??

Left the wort for about 15 mins instead of jumping straight in there, then instead of putting the syphon straight to the bottom of the pot had it sitting somewhere in the middle till the volume got down quite a bit, making sure to keep the plastic away from the bottom of the pot...