Quick question re BIAB

[Rivvo]

I am looking at buying a pot for BIAB but I am unsure which size to get, I would like to make 20 litre batches, looking at beersmith the amount of mash water, sparge water etc changes quite a lot, which size would I be best to order, bearing in mind I am limited to a domestic gas hob for heating, any suggestions please?

 

[rpt]

I use a 40L Buffalo (electric) boiler which is the perfect size for standard strength 23L brews. Don't know how well a pot of that size would work on the stove top.

 

[Rivvo]

I was going to stick to 30 ltrs (and have provisionally ordered one) but a lot of the recipes seem to start with a mash volume of close to 30 ltrs not including any sparge (if required) I wonder how quickly it would heat up on the hob, I am going for aluminium so it heats quicker but also cools quicker.
I was going to make an insulated wrap for it to retain the temperature better.

 

[Rivvo]

Actually answering my own question, I think I'm going to have to maxi biab and add the sparge water 15 minutes from boil finish, that is if I'm understanding the principle correctly?

 

[alymere]

If you have the time do some research on this site http://www.biabrewer.info/index.php

 

[Brycey]

I have a 33l stainless steel pot and I'm managing to get 23l into the fv with a sparge of around 8l in a separate pot. I then add this to the boil.

I use 28l for the mash, usually with between 4 and 5kg of grain. With these amounts my pot is full to the brim and sometimes get a little spillage when i put the lid on.

It takes me around 45 mins to an hour to get to a boil on a domestic gas hob using two rings.

Cheers
B

 

[Rivvo]

Cheers I am now looking at getting an outside gas burner but I've no idea of what wattage is required, I'll have to ask in the shop.

 

[Rivvo]

Alymere, from the short time I've had to look on that site it seems that their preferred option is to put all the liquids in from the start, I'm not sure I'll be able to manage this with pot size, burners etc, I may have to go all out for a 50 litre and outside gas burner :| but I'll have to brew in the garden on nice days only.



Unless I clear the garage out :shock:

 

[rpt]

It is always best to do full volume BIAB but many people do successfully do maxi BIAB. Get the BIABacus spreadsheet and fill in a recipe with your pot details. You can post it in the forum and get feedback on whether you are trying to get too much out of your kit.

 

[Rivvo]

Thanks rpt, I may do that, but having thought about it a bit more I may stick to the 30 ltr pot and just do smaller brews, that way I can experiment more and try doing a wider variety without running out of space. I reckon I could do 10-15 ltr brews without changing the pot size.

 

[Algernon]

70l pot on gas hob, max boil so far 44l - it's ok, but you can't move it once full unless you like risking wearing 40+ litres of hot syrup.
As for heating times, you can get at least 2 rings under it so it actually heat fairly well - 20 mins to dough in temp, if you fill with hot from the tap - then around 30 mins to boiling, holds a rolling boil with 1 large ring under it,
Not sure if that helps...

 

[Rivvo]

Thanks, sounds a bit risky to me, I think I'll go with the 30 ltr, brew smith suggests I can do 18 ltr brews in it without sparging so I can keep true to the ideal :

 

[PaulCa]

If I gather correctly, boiling the full amount including mash, sparge and boil off, you need a 40 litre boiler to do a 22 litre brew. I don't doubt some recipes ask for more and I haven't researched the intricacies of BIAB quite yet.

However if you look at the question, what is the absolute minimum you need the boil, the answer would be the amount you mash with, including any sparging. The minimum you need to mash is 2-2.5 litres per kg of grain. So for a 4Kg grain bill you 'could' mash with 10 litres of water. If you then do only a 5 litre sparge you could boil the 15 litres of wort, top up with boiling water once it's boiling and unlikely to boil over.

If you keep topping it up during the boil to that 15 litre mark, then when done you would add 7 litres of water to the FV. Better to test gravity and calculate how much water your mash efficency allows to reach your OG, or add boiling water with DME mixed in to make the OG.

All this is "minimal" and not "optimal" of course. Hop bill would need varied and to avoid adding DME due to low efficency you may need to up the initial grain bill 10-20% or so and recalculate minimum boil volume.

EDIT: In short, you only need to boil the wort that has come through the grain. If you can make the wort very high gravity, then in theory you can water it down after the boil. DME does not need boiled.

 

[tommidolcetto]

It is always best to do full volume BIAB but many people do successfully do maxi BIAB.

Can somebody explain why this is please?

I get better mash effieciency when BIAB mashing in 3l per kg grain and then dunk sparging twice with the rest of the water than just full volume mash. Am I in danger of affecting quality?

 

[Duxuk]

I have a 32l stainless steel stockpot without tap. For a 23l brew I would start with 22l water which I heat to 68C on an electric hob. I then put my bag in and add the grains. Insulating with a sleeping bag and heatproof may underneath maintains 66C, dropping to 62-64C after 90 mins. I drain and start to reheat the bulk, which takes a while on the electric hob. Meanwhile I open the bag in an FV. I know that if I fill the kettle and pour it into a glass jug, topping up to 2l the water will be 75-80C. Perfect for sparging. 3 jugs is 6l which I stir round and redrain. I add this to the bulk and heat through to a boil. 23l easily fits into a 32l pot and I can get a good rolling boil for my hops. I admit I boil lid on because the hob doesn't give enough heaat otherwise. I use mainly Maris Otter and DMS doesn't seem to be a problem. If I was making pilsner or whatever my system may fail. The result is 23l into the FV (which I've sterilised at this point).
With no tap you have no dead space so efficiency is high and waste negligiable. I use a second sheet of net curtain in the FV as a hop filter.
Go for it :thumb:

 

[Rivvo]

Thanks for the replies guys, forgive my ignorance but what is the issue with brewing pilsners in this way, I presume it is the Pilsner Malt?

 

[Brycey]

I think he was talking about boiling with the lid on although i maybe wrong.

I have done a lager using biab and plan on doing a pilsner next brew but one.

 

[Rivvo]

Yeah thats what I thought, the DMS issues, I assume that doesn't happen with Maris Otter.

 

[Rivvo]

Duxuk, do you have to adjust the hop additions for your method, and if so how do you work this out (I have looked at Biabacus briefly and thought it was written in a foreign language )

 

[Duxuk]

Yes, boiling lid on will allow DMS precursors to build up. It is not a problem with Maris otter but may be with other malts. As for hopping I find that I need to be cautious with bittering hops but liberal with late and dry hops. This is because the slow cooling allows more isomerisation to happen, hencce a shift to bitterness. I have formulated my recipes through experience and tend to use a similar pattern of hopping, since I only want to brew beers from one "family". I would describe my ales as IPAs with American hops.