A Guide To All-grain Brewing In A Bag

[Finite]

I got some polly thread for stitching and will frabricate some device to hold it over the sides with some fencing wire.

Would there be efficiency problems by using a double layer of muslin or am i just better off getting a good stich. (my GF's sister and mother are good at that stuff and have all the gear so ill get them to help me out)

Might even post some pics for others

 

[The King of Spain]

Finite, Im not the guru on this but I would not be worried about efficiency. The bag is only a lining.

Just put my second BIAB away. Used the exact same grain bill as last week all weighed, crushed and vacume packed by Craftbrewer and I got an OG of 1.042 as opposed to last weeks 1.035. I got my water levels right so I did not have to add water throughout and instead of using a paddle I lifted the bag several times during the mash.

Oh, and I squeezed the bag this time

Too easy...

 

[Ross]

Hi Finite,

As Deaves correctly replied, it won't effect your efficiency at all - As long as the liquid drains out of the bag you'll be fine...

cheers Ross

 

[dr K]

17 pages of posts are far too mant for me to read and assimilate but I have read the first post, the instruction booklet and random others.
I must admit that I am a little concerned that such an apparently simple method should produce such apparently flawless results.
Now the idea of a grain bag is nothing new and is an excellent and relatively clean way of doing a small partial/mini-mash which can be added to the bulk of the wort which is derived from extract. You are mainly extracting flavors and colours so actual efficiency is not going to worry you too much.
Let me start from a very very simple base-line, we all know that malted barley contains apha and beta amalyse. We all know that beta works best in the low 60C's, produces much more fermentables (read maltose), that it is heat labile and that alpha works best in the higher 60"s is not as heat labile and produces less fermentables (dextrins say). We also know that when the temperature in the mash is increased to around 72C the alphas are effectively de-natured (the betas have shuufled off the coil some time before.
Basic stuff really.
Now...a question for you...after barley is malted, and the enzymes have been produced what does the malster do to the just "steeped" grains..well..he dries them, he kilns them, slightly different temperatures and methods for various malts (pilsener is the least kilned, something like Munich 2 the most of the base malts). Now he does this for some time, hours and more at temperatures far above 72C, in fact 80C and higher.
So..what happens to our enzymes, particularly the very heat sensitive Beta....
Quite simple really, the drained grains taken from the malting floor (or more likely box) have a very low liquor to grain ratio, the grains are slowly warmed so by the time 70C is passed they have an even lower water to grain ratio.
One of the reasons that, in a mash, the water to grain ratio is so important is that the higher the ratio the less stable the beta-amalyse becomes.
Beta-amalyse does not work independantly of alpha-amalyse, alpha tends to randomly chop the starch chains, producing fermentables and non- fermentables, beta tend to chop up the non-fermentables quite precisely to produce lots of that wonderfull stuff called maltose..as opposed that that terrible stuff sucrose that mega-swill uses.
So, with a water to grain ratio of some 7.5:1 how are we going to maintain decent beta-amalyse levels, well we could mash lower I guess, but then, the alpha-amalyse will be rather sluggish and not give the beta-amalyse much to work on, sure the beta-amalyse may get stuck into the starch chains, but very very slowly as it tend to chomp from the ends of the chains so lots of shorter chains (produced by friend alpha) makes much lighter and quicker work.
We could also mash for a very long time , with, of course, some decent temperature control.
I would love to be corrected on the following point, and as I prefaced, I have not read all the posts, but I am wondering what sort of attenuation the BIAB people have been getting, I have not seen any quantified examples.
The method, as described will produce a highly dextrinous wort, and if, as is suggested, the bag is squeezed to extract the worts, a tannic wort as well (nothing like a bit of mechanical force to pull the tannins out of the husks!)
I am not for a moment saying that you cannot make beer from the BIAB method, goodness me you can take 1.8 kilos of confectionary product laced with hop extract, add a kilo of sugar and dilute the whole lot down to make a wort like concoction which with the addition of a undersized package of unknown yeast will eventually ferment into something called homebrew beer.
I am not for a moment saying that, in the eyes, nose and palate of the beholder it is not a good beer.
I am not for a moment suggesting that the method may be in-efficent in terms of "Expected Starting Gravity", I am suggesting that that gravity may be made up of a higher than normal amount of un-fermentable "sugars" though and I guess that I am questioning the wisdom not of using the method (as it will clearly if only after a fashion work) but of trumpeting it as the New Way, the Better Way or indeed the Only Way.

Kurtz

 

[Finite]

Kurtz,

I think I get the idea of what you are saying, my knowledge is nowhere near that of yours in terms of the process malt undertakes so I cant really reply to that and perhaps another more experianced AG brewer can.

However after reading all the posts and material on BIAB I think it would be a little over the top to claim that Pat and the others that have been exploring this method are advocating it as "the New Way, the Better Way or indeed the Only Way". I think most would agree that this mearly offers a more simplified method of all grain brewing for those with limited space, money, or equipment who would like to try AG. The fact of the matter is that many people have tried this method and more are planning to, if it only ever acts as a stepping stone into AG for those who were perhaps a little hesitant then I guess its worth it.

P.S: BIAB VS AG taste tests has been performed, info here: http://www.aussiehomebrewer.com/forum/inde...076&hl=BIAB

Blake

 

[The King of Spain]

Hey Dr K.

Good stuff mate, from my knowledge level I cant touch you. From a duffer level I can tell you that my first beers all suck (k&K) despite my best endeavours with temp etc. So here I am with with no brains (still) but I've got some yummy beers on the way thanks to Pat and friends. Not dismissing your post mate but I am very happy with the brew I put down today (and last week). BIAB works. Dont care about tradition or anything else. It just works.

 

[hughman666]

17 pages of posts are far too mant for me to read and assimilate but I have read the first post, the instruction booklet and random others.

hi there,

i would suggest that if you read up on the thread a little more, you wouldn't have had to post as many questions.

cheers!

 

[Maxt]

Some good points Dr K.

I think that one of the interesting things about trying new methods, is seeing where the (potential) weaknesses and strengths are.

I know that I wouldn't be grain brewing without BIAB, as it was a more convenient step than getting all the other gear at once.

I don't think any BIAB brewers are advocating geting rid of mash tuns! But at the end of the day the proof is in the pudding, and if BIAB passes the taste test, then who cares!

P.S
My apparent attenuation for my beers has been around 50-60%, (which I would have expected to be higher). This is probably due to the higher FG (due to the presence of un-fermentable sugars?)

 

[Duff]

But Dr K, you've missed the most important point.

It's a simple and easy way to introduce people into AG brewing.

 

[PistolPatch]

Hah! The thread has become more interesting already!

Busy packing today but Brad_G and I are probably the only ones that have comparative figures on batch versus BIAB at this stage so I better put the figures in here.

On the side by side brew we did (an English Bitter)...

Batch achieved 83.7% efficiency into boiler compared to BIAB's 88.4%

This increase in efficiency pretty much matches the results I had in the early days when I compared my batched beers with the same recipe then BIABed.

Attenuation, like grain chemistry, is something I know bugger-all about. However, all the brews that I have done with identical recipes have acheived similiar or the same Final Gravities as when I batch brewed them.

On the side by side brewing we did, the final gravities ended up being identical.

The yeast used in pretty much all my beers was US-56 though we did another side by side brew with SO4 and again acheived identical final gravities.

This all seems to contradict the chemistry so the only thing I can think of is maybe the chemistry side is something more important in large scale operations where even the tiniest factors become of huge importance?

As I said, I know bugger-all about this though so am probably wrong.

Whoops! Back to packing but really enjoying reading your posts guys. Also nice to see you back Finite. Good luck mate!

Pat

 

[dr K]

QUOTE(dr K @ Dec 16 2006, 07:27 PM) *

17 pages of posts are far too mant for me to read and assimilate but I have read the first post, the instruction booklet and random others.



hi there,

i would suggest that if you read up on the thread a little more, you wouldn't have had to post as many questions.

cheers!

Well
I have read every single post.
I find absolutely nothing to convince me that the BIAB method will produce anything other than a dextrinous wort with low attenuation and high finishing gravities, which is precisely what the science behind mashing will tell you. Now, for a low alcohol beer that still has some body thats good, its a good base for a lambic as well but..for a kolsch thats bad !! Am I forgetting that it is a simple starting point for those who want to start mashing ? Well, those on this list who are members of Canberra Brewers may remember a meeting some 18 months or more ago I arrived with a slightly open weaved bag with a qty of cracked grain in it. I heated a qty of water in a 40 litre urn to about 72C and dumped the bag in...why...to show just how easy it was to start mashing, though this was meant as a partial mash to which more water and extract would be added.
The challenge...convince me otherwise.
Post some actual (not expected) opening and finishing gravities, take preferably with equipment that be trusted.

Kurtz
Kanbeera

 

[Zizzle]

Just curious on your motivations here Dr K?

Are you wanting us to see the light that we are wrong, that BIAB produces crappy beers... our taste buds must be shot and we should move to the One True Way of AG brewing?

What benefit do us BIABers get from taking up your challenge?

For me personally all that matters is how the beers tastes, and I like my BIAB beers. No amount of theory can change that.

 

[FNQ Bunyip]

ya go zizz

I'm with you


:beer:

 

[dr K]

My motivations are quite simple.
I see a whole lot of posts about an innovative method of mashing, but a method that does not gel with my understanding of the process (only on the basis of water to grain really).
I am afraid that I am one of those funny old brewers considers that no matter how good a brewer you are you should take at least some basic measurements.
If it turns out that most BIAB brews are showing high levels of attenuation then I have obviously missed something in my understanding....I have never and never will "knock" another brewers taste buds, mine are certainly not what they were 30 years ago.
It is simple curiosity, and if you choose to view it otherwise I guess you are open to your opinion (as I am mine).
By the way....I prefer dextrinous beers and mine are usually on the maltier side anyway.

Kurtz

 

[FNQ Bunyip]

well put Dr K ,

Thanks


:beer:

 

[Zizzle]

Sorry for what must have seemed like a flame from me Dr K.

If you are open to new ideas and haven't already written it off due to preconceived notions then I look forward to your contributions. I would encourage you to spend $6 at spotlight on the material, give it a go and post your results. Start with the observable outcome, then try to come up with a theory. Maybe we all will reach the conclusion that BIAB suits some styles better than others, but lets have evidence.

Maybe I'm too cynical, but I have seen it go the other way where someone comes in on a crusade to "prove" everyone wrong with their own interpretations on theory, while expecting everyone who disagrees to do all the work and provide the evidence.

I didn't want to waste the time responding if that was the case.


Back to the original posts. I've only got a handful of BIAB under my belt, but for each one I have squeezed the bag. I cannot detect what I believe to be the taste of tannins in those beers. Someone posted the theory that over rinsing the grain brings out tannins, not squeezing. Seems to fit my observations.

A quick google brings up:

measuring the gravity of the final runnings can tell you when to stop sparging. The general rule of thumb is to stop before the gravity drops below 1.010 or 1.008. Below this gravity, tannins are extracted.

Obviously that definitely won't be the case with BIAB. Maybe the grain being in high gravity wort helps keep the tannins in during the squeeze? I don't know.


The last BIAB I did was a Oatmeal Stout. Unfortunately I mashed too low, and I can't seem to find the figures, but I remember it having excellent attenuation. It is very dry... a lot of alcohol taste. I would prefer much more body.

You mention you had a 40lt urn at 72 degrees: that temp seems high for a full volume mash, how much water did you use and what was the temp after the grain was added?

 

[PistolPatch]

Howdy Kurtz,

I'm a bit confused on the basic measurements comment as, most BIAB brewers do pay special attention to measurements though, like anyone, one or two may forget some things on their first brew! Accurate figures are important. In fact, only a few weeks ago in this thread, I listed some measurements that people new to AG should take special notice of.

As mentioned before, I'm a bit short of time at the moment but as specified this morning the figures show no probs with attenuation. More specifically 1.010 on lagers/pilseners (with Saflager 34/70) and 1.014 for darker beers such as the Scwartz (though this was brewed with the ale yeast, US-56).

I'm enjoying the education on the grain chemistry however, I think that some of your comments such as the, 'you should take at least some basic measurements,' or, 'provide real figures,' or people here saying BIAB is the, 'only way,' are not only incorrect but also make the BIAB brewers sound like a bunch of cowboys which they are not. They are, as a generalisation, keen as mustard with a thirst to learn. They are certainly not, 'redneck,' brewers.

I'm not sure if I can give you any other figures but I'm thinking that those I provided today would be enough to show that BIAB is getting slightly higher efficiency and achieving the same FG as batch-sparging without any noticeable taste differences. (Hoops, the only one who got the triangular test correct, found the BIAB beer to have slightly less body than the batch but also less astringency.)

I think that last para sums up our experiences to date.

All the best,
Pat

 

[Maxt]

In the interest of science...
My BIAB FG's.

Porter 1 : 1020 (Windsor)
APA: 1012 (US-56)
Porter 2: 1022 (Windsor)
Aussie Lager: 1012 (Saflager)

 

[dr K]

woooo..lighten up a bit lads..
have a read of my posts...I was inquisitive and gave the reasons why in the sense of how enzymes work in a mash with particular reference to mash thickness. I admitted (in fact pre-faced my post) that I had not read all the posts but was interested in some actual figures that might dis-prove what I thought.

I am then told that I should read them all and I will find the answer....so I did, all 240+, and what did I find, well a lot but not a single post with actual starting and finishing gravities, the closest I found was one that was 1022 or so, but then this was dimissed as a dodgy instrument a post or two later, I got another that seemd indicate (but only indicate) a high finishing gravity.
After my initial post one brewer commented that attenuation seemed low and that that would indicate a high level of unfermentables (which is what the science says will happen)
Did I say that BIABS are cowboys, rednecks, I do not think so, in fact my call for actual figures was based on the premise that these measurements had been taken (as I am sure that they were)

So, PP I think that I can sort of get something from your

the figures show no probs with attenuation. More specifically 1.010 on lagers/pilseners (with Saflager 34/70) and 1.014 for darker beers such as the Scwartz (though this was brewed with the ale yeast, US-56).

I think that you mentioned your Scwartz was 2.5% alc somewhere? (#133)
Would I not be correct if I suggested that your opening gravity was 1.033
Further would that not give you an apparent attenuation of about 58%?
Given that the usual range for this yeast is in the 73-77% range I think that is a fair call to say the attenuation was low, which is precisely what the science would indicate.

To reiterate...at no stage have I said that BIAB will not work, but I have indicated that I felt that the result would be a dexrinous wort with low attenuation....which it appears to be.
I also pointed out that I prefer more dextrinous beers.

I am not knocking anyone, or their processes, I am merely making an enquiry....and I have had two responses, both indicating low attenuation.
Guess my major error was that I made the mistake of mixing science with brewing.

K

 

[The King of Spain]

My first BIAB had an OG of 1.035 to which I added some DME to get to 1.044 target. The FG was 1.008 using a Nottingham yeast.