Easy guide to BIAB.

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It's interesting that it claims that BIAB was invented by members of an Australian brewing forum. I've got a Dave Line book from the 70s where he describes BIAB methods.

One thing the article mentions that surprised me was the need for mash-out, suggesting that efficiencies would be poor otherwise. I don't think I've read that before.
 
rpt said:
It's interesting that it claims that BIAB was invented by members of an Australian brewing forum. I've got a Dave Line book from the 70s where he describes BIAB methods.

One thing the article mentions that surprised me was the need for mash-out, suggesting that efficiencies would be poor otherwise. I don't think I've read that before.

I've been told that the late Dave Line got very close without actually inventing BIAB. I don't have the book, does he talk about doing the whole process in one vessel, or is he using a mashing bag in a separate vessel?

[edit] I do a mashout just 'cos it gives me something to do, but it didn't make any measurable difference to efficiency. Stirring the mash more often definitely did, so it could just be that people tend to stir during their mashout :)
 
I've just had another look at the two guides to BIAB I am thinking of (calumscott's guide here and the Australian BIABrewer Commentary) and they do actually both mention mash out. But the Australian guide recommends against doing it unless you have a hook and pulley and industrial gloves.

I'll have to look at the Dave Line book and see how close to full volume BIAB he is.
 
What does a mashout do in BIAB?

You raise the temperature to over the operating temperature of the enzymes and possibly even denaturing them (I haven't looked to see at what temperature the are denatured...) so as to effectively stop them working thereby holding the balance of maltose to longer chain unfermentible sugars in place while you faff around draining your bag and collecting additional runnings and whatnot.

Seems like a good idea to me. It's not going to improve efficiency (unless I'm missing something), the reverse if anything - it's going to stop the beta amylase during the rise quicker than the alpha so your efficiency is set then, you might get some more soluble but unfermentible sugar during the rise then all the enzymatic activity gets stopped...

...or at least *I think* that's why you do it. Surely it's more to do with the style of beer you want rather than the style of brewing you employ?
 
ive seen similar to biab in some old 60's books where a mashing bag was involved... :thumb:

but i think with modern day, communications and technology it has now become more of a science, producing some great beers.

from what ive read it would be daft not to do a mash out,
it seems to take the part of the sparge with hotter water,
which releases sugars stuck to the grain hausks...so im led to believe :wha:
 
Duxuk said:
I'm moving shortly to BIAB from partial mash. This may have been posted before but I'm putting it on again because it's an idiots guide to BIAB so suits me!

http://www.thebrewingnetwork.com/forum/ ... php?t=4650

So with a bigger stockpot and a bag I'm fully ready!


its an interesting article .. theres a lot to read there... :thumb:
 
calumscott said:
What does a mashout do in BIAB?

You raise the temperature to over the operating temperature of the enzymes and possibly even denaturing them (I haven't looked to see at what temperature the are denatured...) so as to effectively stop them working thereby holding the balance of maltose to longer chain unfermentible sugars in place while you faff around draining your bag and collecting additional runnings and whatnot.

Seems like a good idea to me. It's not going to improve efficiency (unless I'm missing something), the reverse if anything - it's going to stop the beta amylase during the rise quicker than the alpha so your efficiency is set then, you might get some more soluble but unfermentible sugar during the rise then all the enzymatic activity gets stopped...

...or at least *I think* that's why you do it. Surely it's more to do with the style of beer you want rather than the style of brewing you employ?

Yep, that makes a lot of sense. I'm hitting 85% mash efficiency with my BIABs, and I can see why you might want to mashout to hit a lower efficiency for some beers.
 
artyb said:
ive seen similar to biab in some old 60's books where a mashing bag was involved... :thumb:

My pet peeve with BIAB is the name! I wish the Aussies had called it "mash in a bag"; it's just an AG process with different approach to sparging - i.e. don't bother :)
 
Sorry if I offended Vossy1. I have not often ventured to this part of the forum and didn;t realise it was for forum members to write informative articles.
On the plus side I have now read CallumScotts more scientific article and the info will be of a lot of use in a couple of weeks when it's "B" Day. Before that I may need to crack off another partial since I am still not fully equiped.
I once knocked SWMBO's sewing machine over whilst slightly...........you can guess the rest. I glued it back together but she'd never allow me to use it. Easy life, she'll sew the bag up! :thumb:
 
I had a look at Dave Line's book last night. He sparges in a bag and one of his methods mashes in a bag, but not with the full volume of water. I think all his recipes involve liquoring back. Modern BIAB mashes with the full volume of water and doesn't involve a separate sparge (although maxi BIAB does).

So I seem to be wrong on both my observations! :oops:
 
That's right rpt, he uses a bag but is more 3v with the bag to contain grain for sparging before people got into the cool box systems got popular. My maxi biab method is a hybrid of Dave line and the newer techniques.
 
I read that raising the temp at the end of biab decreases viscosity of the wort allowing you to drain more sugars from the grain and bag, don't know how much difference it makes in reality though as never done it
 
wigwamheed said:
raising the temp at the end of biab decreases viscosity of the wort allowing you to drain more sugars from the grain and bag

Like you, I would struggle to grasp that making any appreciable difference. I just can't see, at the moment anyway, why you *wouldn't* have a mashout step.

Anyone propose any negatives?

Risk of scorching grain and bag if using electric elements I suppose...? Any more?
 
As part of an ""experiment" trying to measure the effect of mashout on efficiency I've collected the following figures for my last couple of BIAB brews.
All samples cooled to hydrometer calibrated (20C) temp. I've included all the figures, even the ones where I'm sure I've made a mistake...

Brew 1 - Mashout gain = 10 points
90 mins reading 1.046
126 mins reading 1.056

Brew 2 - Mashout gain = 7 points
60 mins reading 1.036
81 mins reading 1.043

Brew 3 - Mashout gain = 8 points
90 mins reading 1.026
109 mins reading 1.034

Brew 4 - Mashout gain = 8 points
90 mins reading 1.032
110 mins reading 1.040

Brew 5 - Mashout gain = 14 points
90 mins reading 1.038
110 mins reading 1.052

Brew 6 - Mashout gain = 1 point
90 mins reading 1.040
110 mins reading 1.041

Brew 7 - Mashout gain = 2 points
75 mins reading 1.044
105 mins reading 1.046

It's way too early to even try and draw any conclusions from the above figures but I'll keep on doing a mashout and recording the findings (The last two brews were done with Weyermann Pils malt, all the rest with Maris Otter... :wha: :hmm: ).

As to the name BIAB - when I explained to a friend of mine what the abbreviation meant he asked me if it's related to a colostomy :sick:
 
Good data, nice one lambert :)

So you're recording wort gravity pre- and post- mashout? I'll do the same and see what I find. I guess it's hard to control for other factors like size of grain bill and wort ph from darker grains but it's still interesting.

It looks like you initially got good gains from a mashing out, which have dropped off? I wonder if, like me, your overall process has improved over time, making the effect of mashing out less dramatic?
 
bunkerbrewer said:
It looks like you initially got good gains from a mashing out, which have dropped off? I wonder if, like me, your overall process has improved over time, making the effect of mashing out less dramatic?

It's too early to say, but I think that it might be the grains!
 
calumscott said:
I just can't see, at the moment anyway, why you *wouldn't* have a mashout step.
Because it's something else to do - so I'd only want to bother if it was likely to have any value. However, it does look like it's worth doing.
 
Mashout temp? What would be the best temp to aim for? 85C?
I notice that the recommendation is to keep stirring whilst heating to avoid a temperature gradient form outside to the middle of your grain bag. I can see this being important. All that stirring might also release more sugars which are trapped inside the grains. I thought for an easy life I might not bother but this discussion has made me think again. I haven't been doing a mash out with my partials, just sieving the grain out and sparging.
 
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