Question about BIAB and sparging...

The Homebrew Forum

Help Support The Homebrew Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

timcunnell

Regular.
Joined
Jun 24, 2015
Messages
262
Reaction score
48
Location
NULL
Hey guys. I'm really excited about giving my new Peco boiler a go on Saturday. The wife is working all day so I've got the perfect opportunity to have a hassle-free brew-day, and I am determined not to have any mishaps!

Having looked into the whole AG method a fair bit and reckon I have just about enough understanding now to give it a good crack. But if I am honest, the one bit that really confuses me is sparging. As I understand it (very basically) sparging is the process of washing sugars out of the grain after the mash. I noticed that the instructions say the sparge water should be 80 degrees. So does that mean the sugars extracted in the sparge process are unfermentable?

There are two main things I just don't understand:
1 - How do you physically sparge with BIAB method? Would you drain the wort at the end of the mash, then rinse the grain in the boiler before removing the bag and re-adding the wort? Or would you remove the bag and rinse the grain in another vessel perhaps?
2 - How can the sparge be consistent? It strikes me that the amount of sugars sparged out of the grain could vary quite a lot from one brew to the next, so this could lead to varied results in terms of flavour or ABV?

Sorry to ask such basic questions, but as always your knowledgeable input is greatly appreciated!
 
For question 1 it mostly depends on the space you have in the boiler - the Archimedes principle holds true as I learned with my first BIAB brew. 19L kettle, 17L of water and 4.5kg of grain = very wet hob and floor!

For a 9.5-10L brew i heat up 17L of strike water in my kettle then split it into mash water (about 10L) and 7L into an empty FV to use as sparge later. Once your mash is up you can do a number of different sparge methods:

1. Dunk Sparge. Lift the bag up, drain it in your kettle/boiler then using an empty FV (or similar) dunk the bag into hot water.
2. Standard sparge. Lift the bag up, drain it in your kettle/boiler then using an empty FV (or similar) put the bag into it (over a sieve or similar) and wash the grains with hot water.

There are other methods but these are the ones i have tried. The latter has been most effective for me. If your boiler has a false bottom and spigot then BIAB is out of the question and you can proceed to AG brewing without the added hassle.

I'll leave others to answer question two as they have more experience than i!
 
I am assuming you're planning on a 23l brew? the reason I ask is because with a smaller one you could do a true BIAB where you mash and mash out without a sparge.. but if you are doing 23l what you will need to do is split your water what I did in teh past and a lot of brewers do now is mash with about 21L of water and then dunk sparge in 10ish l of 80ºc water which can be done in a fermenter (while your post mash wort heats up to boil).. when you have drained all out add this to your boiler (if you have too much then do do it all at once) you can add more sparge water to the boil as it goes down..

Does that sound viable?
 
1. Just do what you find easiest. Your suggestions sound fine. Or don't bother; you only lose a little efficiency. You aren't running a commercial brewery.

2. Sparge efficiency (if you want to call it that) depends partly on how much residual sugars there are in the grain. This varies dramatically from brew to brerw, but for relatively dry mashes (where you are aiming for very high OG) you will gain relatively more by sparging as the wort gets saturated with sugar and struggles to extract even more sugar.

In short: it's worth the small effort to sparge. I recommend sparging at mash out temperature as it will help to release the sugars are little more easily. The downside being that the increased temperature will burn your hands more when you come to squeeze...
 
I am assuming you're planning on a 23l brew? the reason I ask is because with a smaller one you could do a true BIAB where you mash and mash out without a sparge.. but if you are doing 23l what you will need to do is split your water what I did in teh past and a lot of brewers do now is mash with about 21L of water and then dunk sparge in 10ish l of 80ºc water which can be done in a fermenter (while your post mash wort heats up to boil).. when you have drained all out add this to your boiler (if you have too much then do do it all at once) you can add more sparge water to the boil as it goes down..

Does that sound viable?

Thanks very much for your reply, Covrich! You're right, I am planning a 23l brew. Or at least I assume I am - apparently my target boil volume is 27l according to the instructions - so I am thinking this should reduce to 23l after the rolling boil?

I am liking the sound of this dunk sparge, I have to say! Although my only problem is heating up another 10l of water to 80-degrees. I got he Peco boiler mainly because I only otherwise have a halogen hob which isn't good at all for heating even a moderate-sized pan of water.

(Whoever said a watched pot never boils was obviously using a halogen hob!).
 
Thanks very much for your reply, Covrich! You're right, I am planning a 23l brew. Or at least I assume I am - apparently my target boil volume is 27l according to the instructions - so I am thinking this should reduce to 23l after the rolling boil?

I am liking the sound of this dunk sparge, I have to say! Although my only problem is heating up another 10l of water to 80-degrees. I got he Peco boiler mainly because I only otherwise have a halogen hob which isn't good at all for heating even a moderate-sized pan of water.

(Whoever said a watched pot never boils was obviously using a halogen hob!).

Could you not heat some up in a pan and pop the kettle on a few times pouring into the FV.. I know it probably isn't ideal but whatever works!!

If you get 10liters dunk the bag in and give it a good stir and leave it to sit.
 
1. Just do what you find easiest. Your suggestions sound fine. Or don't bother; you only lose a little efficiency. You aren't running a commercial brewery.

2. Sparge efficiency (if you want to call it that) depends partly on how much residual sugars there are in the grain. This varies dramatically from brew to brerw, but for relatively dry mashes (where you are aiming for very high OG) you will gain relatively more by sparging as the wort gets saturated with sugar and struggles to extract even more sugar.

In short: it's worth the small effort to sparge. I recommend sparging at mash out temperature as it will help to release the sugars are little more easily. The downside being that the increased temperature will burn your hands more when you come to squeeze...


Thanks Rob that is very helpful - and re-assuring to know that my proposed methods should be okay.

I am interested in your last sentence as that reminded me of something else I meant to ask on here! Should you squeeze the grain bag then?? When I previously tried a simple AG brew on the hob I noticed that you go get a lot of water held in the grain when you lift the bag out - and I squeezed it out then. But to be honest I wasn't sure if that was right or not!?
 
Absolutely! Squeeze until dry!

Thanks! I don't know why, but that was just something I was never too sure about! And for some reason I was a little reluctant to squeeze it in case it released something you didn't want going in your beer!
 
Hi Tim,

I am planning a brew day on Saturday as well wiht my Peco boiler, good luck with yours and enjoy.

I have done many partial mashes before moving onto BIB with the Peco boiler and have always dunk sparged in hot water at 75-80°C. I get my water ready (8-10litres if you can manage that much using kettlefuls, 5-6 litres if not) in the seperate FV then lift the BIAB containing the grains out of the boiler at the end of the mash and dunk them into the FV. Leave for 10 mins and stir a bit then lift up and drain squeeze the bag out a bit then stand the bag over the FV in a large sieve to drain any residual water out as best you can.

I wear some black 'marigolds' for handling/squeezing the grain bag - it is jolly hot !

Always been there or thereabouts with my numbers so don't overthink it too much.

You will need 25-26l at the end of the boil to get 23litres in your FV - so keep topping up to 25-26 litres during the boil.

Enjoy the brew day.
 
I dunk sparge while the rest of the wort is heating up to boil - don't use a great volume for the sparge, just 2 kettle fulls of boiling plus one of cold. The sparge water after the dunk is quite coloured and sweet so I'd guess it helps greatly with your efficiency.
 
Yeah, you could always use a spare pan or the kettle to get your 80c sparge water. Kettle may be a little small though.

As I mentioned before though, don't worry too much about the extra efficiency you gain. It may only be 5-10%, and grain is cheap.
 
Hi Tim,

I am planning a brew day on Saturday as well wiht my Peco boiler, good luck with yours and enjoy. What are you brewing? I am going for the porter kit that HBC do - which I got thrown in with the BIAB kit.

I have done many partial mashes before moving onto BIB with the Peco boiler and have always dunk sparged in hot water at 75-80°C. I get my water ready (8-10litres if you can manage that much using kettlefuls, 5-6 litres if not) in the seperate FV then lift the BIAB containing the grains out of the boiler at the end of the mash and dunk them into the FV. Leave for 10 mins and stir a bit then lift up and drain squeeze the bag out a bit then stand the bag over the FV in a large sieve to drain any residual water out as best you can.

I wear some black 'marigolds' for handling/squeezing the grain bag - it is jolly hot !

Always been there or thereabouts with my numbers so don't overthink it too much.

You will need 25-26l at the end of the boil to get 23litres in your FV - so keep topping up to 25-26 litres during the boil.

Enjoy the brew day.

Thanks Spapro! And good luck with your brew day too! Incidentally, I picked up all the bits from B&Q last night and have finished my immersion chiller. I am really pleased with it! In fact I am so pleased I might even post a quick pic of it in that other thread!

Anyway - thanks very much for the great advice as always! I shall def go with the dunk method then. I will post updates when I give it a try!

Cheers!
 
Good thread this, thanks to the OP and those who answered.

I am in the same position as the poster and did wonder wether to sparge or not to. Having just done a mini mash for the first time I started with 13L hoping to make 10. I ended up with 7 after the boil ! So you may well have to top up as you go. It is for this reason I ended up buying a 50L SS pot and a gas burner so I can do a full BIAB, ie prob 32L to start the mash to end up with 23 after the boil.
I have squeezed the bag after my partial mashes (gloves!) and got a fair bit of milky sweet stuff out so will prob continue to do so.

Just shows though, listening to the OP's suggestions and the answers, that followed, it isn't an exact science....

P.s after mashing 13L in a 15L pot I ended up with approx 11L ready for the boil. It very nearly boiled over !!!! You have been warned ;-)
 
Good thread this, thanks to the OP and those who answered.

I am in the same position as the poster and did wonder wether to sparge or not to. Having just done a mini mash for the first time I started with 13L hoping to make 10. I ended up with 7 after the boil ! So you may well have to top up as you go. It is for this reason I ended up buying a 50L SS pot and a gas burner so I can do a full BIAB, ie prob 32L to start the mash to end up with 23 after the boil.
I have squeezed the bag after my partial mashes (gloves!) and got a fair bit of milky sweet stuff out so will prob continue to do so.

Just shows though, listening to the OP's suggestions and the answers, that followed, it isn't an exact science....

P.s after mashing 13L in a 15L pot I ended up with approx 11L ready for the boil. It very nearly boiled over !!!! You have been warned ;-)


Yep you gone down the same route as me. I did my first one last week .. my water numbers need adjustment but yes full mash and then mashout and on to the boil.. I think that's what BIAB was originally designed as a whole complete water in one vessell and mash..

But of course with smaller boilers people adapt and add the sparge stage which works just aswell.
 
Yep you gone down the same route as me. I did my first one last week .. my water numbers need adjustment but yes full mash and then mashout and on to the boil.. I think that's what BIAB was originally designed as a whole complete water in one vessell and mash..

But of course with smaller boilers people adapt and add the sparge stage which works just aswell.

Plus of course, with the true BIAB it's suggested that even a mashout or sparge is unnecessary. I think it's probably our obsession with squeezing every last bit of fermentable goodies out of our grain. I suppose a bit of extra grain thrown in at the mash makes up the numbers and doesn't break the bank...

Out of interest Covrich, how far out were your water figures ?
 
Plus of course, with the true BIAB it's suggested that even a mashout or sparge is unnecessary. I think it's probably our obsession with squeezing every last bit of fermentable goodies out of our grain. I suppose a bit of extra grain thrown in at the mash makes up the numbers and doesn't break the bank...

Out of interest Covrich, how far out were your water figures ?

A couple of litres i had I think nearly 30 liters pre boil water. A few things which threw it out though.. I did a cold steep with roasted grains and perhaps this threw the numbers out a bit I also used flaked barley.. SO things like grain absorption were out.. These are things I will adjust for brew number 2 and go forward.. In my case I also made the stupid mistake of making an appointment so I had to rush things otherwise I would have just boiled longer.

I ended up a few points off my target OG however bare in mind I had 3 or so liters extra I think I would have hit 72% efficiency this was a mash which I only did for 60 mins (I think Biab they recommend a bit longer) I did lift the bags and try a sort of mash out and stir. The whole brew was a bit hectic due to me adding time pressure.

But I actually think once down the process will be easy and like you say possibly just skip a mashout too. If you can get consistency even at 65% just add a few 100gram of grain to get your target OG.

Apologies if this seems slightly digressed although if the OP wants to consider a full BIAB for say 19litres this may well be worth noting!!
 
Thanks Covrich, that's useful info.
The pleasing thing is, even when we don't get it 'exactly' right, we generally end up with good beer...
 
Apologies if this seems slightly digressed although if the OP wants to consider a full BIAB for say 19litres this may well be worth noting!!

Not at all Covrich this is really interesting stuff! One of the MANY reasons I am fascinated by home brewing is because the more I scratch the surface the more I discover that there is to learn. I am determined to crack this AG brewing stuff now, and there is clearly a lot to learn.

Interestingly (as its cropped up now) one of the things I was wondering about, but didn't understand and therefore put to one side for now is the issue of efficiency. I've been playing around with the Brewer's Friend app which I've found interesting. I just couldn't get my head round the bewhouse efficiency part. Is that related to extracting sugars from the grain then? Or how much water you lose? I wasn't sure how efficiency was measured/calculated in % terms?
 
Not at all Covrich this is really interesting stuff! One of the MANY reasons I am fascinated by home brewing is because the more I scratch the surface the more I discover that there is to learn. I am determined to crack this AG brewing stuff now, and there is clearly a lot to learn.

Interestingly (as its cropped up now) one of the things I was wondering about, but didn't understand and therefore put to one side for now is the issue of efficiency. I've been playing around with the Brewer's Friend app which I've found interesting. I just couldn't get my head round the bewhouse efficiency part. Is that related to extracting sugars from the grain then? Or how much water you lose? I wasn't sure how efficiency was measured/calculated in % terms?

Yes basically the amount of extraction you get from the grains. 70% seems to be the average target to shoot for.. But I think ideally you want consistency.. When I did my HBC IPA kit in two halves.. my first one was 70% efficiency but the second was 85% the higher % one whilst stronger wasn't quite as well balanced.

If you get 65% everytime like I said above no great shakes just shove some extra pale malt in..

I cannot talk yet I am still trying this new setup so I myself am trying to work out what quantities and proccesses will work for me.. But it is all trial and error
 

Latest posts

Back
Top