Finer Crush For Biab

[jayse]

Aye, a finer crush definitely will expose more of the grain for sugar extraction (without getting into the coarse crush & floating mash theory). It's getting the sugar out of the mash that poses more difficulty, and I found myself wondering how well this fares in a bag.

I think kai has posed the questions you need to be looking into in such a thread.
It is entirely possible to get less effiency out of a finer crush and too me I would think with the whole BIAB thing and how it works a more traditional crush would be best so the liquid can flow easily out of the great big bag you have hanging and dripping into your kettle.
With a fine crush you could actually heave out the bag and leave it hanging to drain but the finer crush will trap in a lot more of the wort and as such leave you with less, not quite the same as a stuck sparge as you have retrieved most of the liquor just there is a reasonble amount left trapped in there.
There is also a higher chance of balling (clumping) of course.
Now if no one has found this to be the case in practice with fine crushed grists in BIAB then well...hey all good.

 

[Ross]

Why don't you think there would be any gain from a finer crush? I have always found my efficiency improves significantly if I crush finer or crush twice. The only thing holding me back is the increased likelihood of a stuck sparge as I use a false botton. But with biab that problem doesn't apply. And with the fine mesh of a biab bag I would think you'd want to crush as fine as possible. In these days of higher prices etc I reckon you might as well try and get the most out of your grain.

So good to hear you're offering to crush finer for biab folk!

...because we already crush on the fine side & from a lot of experience I reckon we have the mix pretty well spot on. But as i said, if guys want finer, who are we to argue

cheers Ross

 

[T.D.]

...because we already crush on the fine side & from a lot of experience I reckon we have the mix pretty well spot on. But as i said, if guys want finer, who are we to argue

cheers Ross

That's good to see Ross. My point was more that what is "spot on" for one false bottom type or sparging technique may be different to others. BIAB in my view would be one technique that could tolerate a signifcantly finer crush than possibly any other method. I presume your mill setting would be aimed at more commonly used methods (the "median masher" if you will), which arguably are not suited to a particularly fine crush.

 

[Cocko]

I ordered a finer crush, for BIAB, and picked up 7%.

Although that said, my efficiency can be a little up and down anyways.. so who knows!

I can tell you a little OT: I ducked out last weekend during a mash, BIAB, and got caught up, ended up with a 2 1/2 hour mash!! Dropped from 67 > 61 - Again

I pulled an 83% out of that brew - my average thus far is around 70%...

I am building my 3v ATM but will continue to tool around with extended mashes for sure...

 

[Thirsty Boy]

The point of a finer crush in a BIAB brew (and any other) is not to increase the extraction of sugar from the mash - but to increase the production of sugar in the mash. Virtually every mash has an amount of unconverted, still bound up in the grits, husks etc starch. The finer you crush, the more readily the liquor and therefore the enzymes can access that starch, and the more sugar you will make in the first place. Then you have to go about getting it out of the mash tun. If you mill very finely in a mash or lauter tun - this might be a problem. It isn't in a BIAB mash.

There is no "trapping" of extract, nor any channeling, nor any of the reasons for an inefficient lauter if you BiaB - the only downside is the lack of a sparge to rinse the grain (assuming you don't do one that is) and the fact that by traditional standards you get a turbid and therefore low quality wort. So what you lose on the one hand, you get back on the other.

In BIAB your efficiency is about how well you convert your starch - and then about the size of your grain bill. Because the losses are all about the liquid that remains in the grain, and that increases with the amount of actual grain. So while it might not matter quite as much for a traditionally lautered and mashed brew - the limits on crush being around the ability to run off at reasonable speed - a fine crush has a marked effect on BiaB efficiency.

BiaB is at the core a mash filter technology - and mash filters get a goodly chunk of their impressive efficiency from the fact that the grist is able to be milled so finely.

BUT - as mentioned above. You get a bit more trub the finer you mill.. so you lose some of that mash efficiency due to kettle losses. I assume that at some point the two would balance out. And the finer you crush - the more of the fine particles that go across will be husk. It matters not that starchy flour makes it through the mesh - that just converts. But eventually I imagine you will get enough husk going across to the boil that it would cause quality issues.

I would draw short of saying "mill it to flour" - but as long as your husks are left in pieces that are visibly larger than the holes in the filter cloth - the finer the crush the better, up till you find your total system efficiency reversing because of kettle losses anyway. Or until you notice the beer not being as good.

 

[PistolPatch]

In answer to your question yes, will crush finer with any volume if requested - Though to be honest, I don't think you will gain anything

Cheers Ross

I wouldn't worry about crushing any finer Ross. Whilst I enjoy reading and respect the substantial scientific knowledge conveyed so well above, the application and practicality of this knowledge is way beyond a home brewer and certainly misleading to a new home brewer.

Measuring a 4000 litre brew with accurate equipment still has an error margin so what possible hope can us poor homebrewers with a brew length of 19 or 23 lts have in measurement? We rarely even brew the same recipe over and over let alone even have accurate hydrometers!

I think it is a real shame that in the home brewing world, we have such a focus on measurement. Our strong point, as home brewers is that we have so much freedom on ingredients compared to large breweries but still, we talk about improving efficiency by 2%.

I think experienced all-grainers should emphasise this. Let's face it, unless you brew exactly the same recipe 20 times, and filter (and temper) your wort for gravity readings, you can not hope as a home brewer to accurateley measure any increase in efficiency.

Trying to track any improvement in quality can be even harder.

It would be nice to see more a focus on successful recipes than a focus on measurement that any true scientist would shoot to pieces in two seconds in our mini-brewing world.

Let's just brew a beer we like and teach others the practical way to do the same.

A good and understandable question from BribieG but I hope Bribie, that after reading the above, the least of your worries should be the crush.

Ramble, ramble,
Pat

 

[crundle]

There is always the option of running the grain through the mill twice at the original setting instead of using a finer setting initially. I saw some pictures the other day that showed a much finer result using this process, so the mill settings that people are used to don't need to be altered.

As said by others, what you gain on the one hand you lose somewhat on the other. I have tried using a swiss voile hop bag as a filter in the neck of my cube while transferring from the urn to the cube (BIAB), but recently was told that a pool filter bag from Kmart was quite effective at stopping trub getting through, so will be trying this in my next brew to attempt to minimise losses.

Crundle

 

[T.D.]

I think it is a real shame that in the home brewing world, we have such a focus on measurement. Our strong point, as home brewers is that we have so much freedom on ingredients compared to large breweries but still, we talk about improving efficiency by 2%.

But surely if you could obtain even 2% extra efficiency for no extra time, effort or risk of stuck sparge, then why on earth wouldn't you do it!

I can understand your argument if comparing batch sparging and fly sparging, because the efficiency gains of fly sparging are offset by the extra time required and a more specialised setup. In that case yeah, maybe the extra effort of fly sparging is not enough to justify the efficiency gains (although it may be for some people). But in this case we are talking about a very simple modification to the process (finer crush) that has been said to raise efficiency significantly. Why wouldn't you do it???

And re crundle's comments, you certainly can crush twice as an alternative to reducing the roller gap. This is what I do every brew now and I am not only getting more consistent results but also higher efficiency.

 

[Bribie G]

I rang CraftBrewer this morning, they hadn't processed my order yet for the Pale Pilsener, Rosscoe Junior has done a finer crush for me, blessim, and should arrive tomorrow. I'll do a couple of my usual house lager and looking forward to the results. Reading Thirsty's post another thing that occurs to me, regarding conversion of starches, is that I use a fair whack of rice in my house brew and maybe a finer crush might give a more 'intimate' juxtaposition of the malt fragments and rice fragments in the mash and get better efficiency that way. Will bump and post in due course.

 

[MHB]

If you ground really really fine and had a good enough filter bag you should be able to get close to theoretical extract yields, especially if you follow the mash regime in here View attachment 27031.



MHB

 

[Kai]

The point of a finer crush in a BIAB brew (and any other) is not to increase the extraction of sugar from the mash - but to increase the production of sugar in the mash.

I meant to have the word conversion in there too, of course...

 

[PistolPatch]

But surely if you could obtain even 2% extra efficiency for no extra time, effort or risk of stuck sparge, then why on earth wouldn't you do it!

I can understand your argument if comparing batch sparging and fly sparging, because the efficiency gains of fly sparging are offset by the extra time required and a more specialised setup. In that case yeah, maybe the extra effort of fly sparging is not enough to justify the efficiency gains (although it may be for some people). But in this case we are talking about a very simple modification to the process (finer crush) that has been said to raise efficiency significantly. Why wouldn't you do it???

And re crundle's comments, you certainly can crush twice as an alternative to reducing the roller gap. This is what I do every brew now and I am not only getting more consistent results but also higher efficiency.

Don't mind me TD. Venting about efficiency is what I do for relaxation :icon_cheers:

I just get worried when brewers get hung up on efficiency after their 2nd or 3rd brew (not BribieG - he's done heaps) and are not at the stage where they fully understand software, measurement etc.

Anyway, I'm really relaxed now :lol:

 

[Kai]

I can understand your argument if comparing batch sparging and fly sparging, because the efficiency gains of fly sparging are offset by the extra time required and a more specialised setup.

Specialised setup?

 

[flattop]

I think we are speaking about 2 problems here, one is process and the other is improvement/output.
As Biab is a "relatively" new science, we are right to question the process and try to work improvements into the process for the advantage of all.

Then we move to the question of improvement over output, if i told you that i could improve the quality of your brews by 2% by cranking a mill by hand for 15 hour before you brew would you do it? Most would say no. IF i said you could improve your brew by 5% by adjusting your mill...... perhaps so...

I am interested in efficiency but i am more interested in whats in the glass.... if it tastes good but it cost me $2 more in grain bill per brew to compensate for my crappy brew style i will happily pay it AS LONG AS THE BREW TASTES GOOD!

PS Crundle did you find the filters?

 

[Guest Lurker]

Oi Kai. Wheres the paddle I made you in that photo? Did you drop it in Jake?

 

[browndog]

I wouldn't worry about crushing any finer Ross. Whilst I enjoy reading and respect the substantial scientific knowledge conveyed so well above, the application and practicality of this knowledge is way beyond a home brewer and certainly misleading to a new home brewer.

Measuring a 4000 litre brew with accurate equipment still has an error margin so what possible hope can us poor homebrewers with a brew length of 19 or 23 lts have in measurement? We rarely even brew the same recipe over and over let alone even have accurate hydrometers!

I think it is a real shame that in the home brewing world, we have such a focus on measurement. Our strong point, as home brewers is that we have so much freedom on ingredients compared to large breweries but still, we talk about improving efficiency by 2%.

I think experienced all-grainers should emphasise this. Let's face it, unless you brew exactly the same recipe 20 times, and filter (and temper) your wort for gravity readings, you can not hope as a home brewer to accurateley measure any increase in efficiency.

Trying to track any improvement in quality can be even harder.

It would be nice to see more a focus on successful recipes than a focus on measurement that any true scientist would shoot to pieces in two seconds in our mini-brewing world.

Let's just brew a beer we like and teach others the practical way to do the same.

A good and understandable question from BribieG but I hope Bribie, that after reading the above, the least of your worries should be the crush.

Ramble, ramble,
Pat

Great post Pat,
Is it really such a dealt that you may have to use an extra 1/2 a kilo more base grain than Joe Blogs down the street to get the same OG? People get hung up on efficiency when they should be concentrating on consistancy and becoming familiar enough with their system that they can confidently brew without having to rely on brewing software to advise them how their beer will turn out.

cheers

Browndog

 

[Kai]

Oi Kai. Wheres the paddle I made you in that photo? Did you drop it in Jake?

I'd just had a bunch of my old stuff delivered from SA. I was having a retro moment with my old paddle.

 

[Thirsty Boy]

MHB - funny, I had half composed a post where I was going to compare BIAB to the various congress mashes.

Interesting to note that all of the congress mashes (ASBC, EBC and IOB) are in fact different and all of them are closer to BIAB than they ar to any other mashing technique. The IOB standard mash is almost identical to a stock BiaB brew. L:G, no-sparge, isothermal temp, finer grind.. everything.

You are right - with a fine filter bag, fine enough grind and constant agitation. BIAB should get pretty close to 100% - it is basically just a 20L congress mash.

 

[warrenlw63]

Hey for you BIAB'ers who crave extra efficiency why don't you tie up your bags and press them in an Apple or Grape press? You'd be up there with some of the Mega Breweries and their mash filter/presses then. You could also incorporate a "very" fine lab grind as well.

Take that suggestion as you will. Is it too remote to work?

Warren -

 

[Bribie G]

Hey for you BIAB'ers who crave extra efficiency why don't you tie up your bags and press them in an Apple or Grape press? You'd be up there with some of the Mega Breweries and their mash filter/presses then. You could also incorporate a "very" fine lab grind as well.

Take that suggestion as you will. Is it too remote to work?

Warren -

Only if It comes with the blonde chick