Is Exceeding Mash-out Temperature A Problem?

Australia & New Zealand Homebrewing Forum

Help Support Australia & New Zealand Homebrewing Forum:

PistolPatch

Well-Known Member
Joined
29/11/05
Messages
2,717
Reaction score
44
I have always been completely confused about decoction mashing. I have never done it and have very little knowledge of it but if I am right in my primitive understanding....

In decoction mashing, you remove a part of the mash (grain and all) and boil it.

In normal mashing it is always frowned upon to allow your mash-out temperature to exceed 78 degrees or so as it will extract tannins etc.

Assuming your pH is right, why is it a problem to exceed 78 degrees or "mash-out" temperature?

There is probably something obvious I am missing here but I would love to get clear on this so thanks in advance,
Pat
 

MHB

Well-Known Member
Joined
1/10/05
Messages
6,690
Reaction score
4,137
Location
Newcastle
You weren't a boy scout were you PP.
If you have ever made billy tea, water tea and sugar, over the fire, bring to a boil.
Rich and sweet leave the sugar out and there would be enough tannin to raise blisters.
Sugar in solution blocks the extraction of most of the tannin, likewise with a decoction; we are taking the heaviest portion of wort and raising its temperature slowly to boiling point.

To just say "Boiling It" is a bit of a misnomer, the decoct is raised through all the sac temps at about 1oC/Minute, so there is plenty of extract there to block tannins.
That said there is usually a fairly noticeable increase in both Melanodins and husk flavours in decocted brews

MHB
 

PistolPatch

Well-Known Member
Joined
29/11/05
Messages
2,717
Reaction score
44
Ah MHB, you de man!

I have made lots of billy tea in my younger days but I think it was always the same way. But, then again, I did have other people's billy teas as well. I am clutching at old memories but am starting to get a glimmer of what you are saying but I reckon you can do better :D.

Remember you are dealing with a simpleton in this area so no big words (like 'heaviest') please.

To 'exagerate' the question, say if I did a BIAB, why couldn't I slowly raise the whole mash from mash temp to boiling point and leave the bag full of grain in the kettle until the end of the boil?

I would never do this of course but why shouldn't I?

;)
 

Thirsty Boy

ICB - tight shorts and poor attitude. **** yeah!
Joined
21/5/06
Messages
4,544
Reaction score
106
Tannin extraction is a curve thing Pat - you don't cross a line and then it starts. Tannins are being extracted all through a mash, its just that when you hit the combination of high temperature and higher pH, they start to be extracted at an unacceptable rate and you can get a flavour impact in your beer.

The issue around tannins is that they are more soluble at both higher temperatures and at higher pH levels - pH probably being hte more important of the two things. In a continuously sparged mash... you are giving it both. High "sparge" temps and also high pH in the form of the sparge water - and if you go even hotter... well, you just make it worse.

In a decoction, you don't just remove any old part of the mash, you deliberately target the solid/thick portion of the mash, leaving behind the more liquid part - and the stock explanation is that this keeps the pH lower in the portion you are going to boil, than it otherwise would be if you used the thinner bits of the mash. Certainly lower than it would be in an over-sparged mash bed. Thus while you are in fact raising the temperature a lot higher, you are keeping the pH under control and minimising the solubility of the tannins.

That's all partially, maybe even mostly, true - but the often unmentioned fact is that decoction does extract more tannins than an infusion mash - and in fact a slight tannin astringency, mostly described as "grainy" is part and parcel of the flavour profile of decocted beers.

So - you do a decoction, traditionally because you have shitty undermodified malt and you have to - and by boiling the thick portion only, you minimise, but obviously don't eliminate tannin extraction while you do it.

So - if you pH is OK, you probably could go higher than the often quoted 78 without necessarily running into major dramas - you will extract more tannins doing it - but is more equivalent to "too many"?? That would be something you would need to find out by tasting the beer.

Question is.... why would you want to go hotter than that?
 

PistolPatch

Well-Known Member
Joined
29/11/05
Messages
2,717
Reaction score
44
[Looks like we posted within a minute of each other TB so you would have missed my last post. I think your above though answers my above! I think it does - the whole mash isn't 'heavy' enough?]

That's a mighty good and informative read Thirsty :super:

Good on ya! I now see what MHB meant by the 'heaviest' part of the mash and a lot of other things. Thanks a heap for the above!

Question is.... why would you want to go hotter than that?
The reason I asked was actually because a bloke on another forum is about to do his first BIAB. He started explaining his problem in this thread. Reading this tells me he can brew kits fine but is having problems any time he does an extract* or a partial. His questions continue from the above thread to this post tonight here.

I have been trying to work out his problem for a bit and then tonight he wrote...

My prevoius method allowed a ton of small grain particles through into the boil so maybe the flavour is more from boiling with grain present and I'm just seeing loads of hot break as a result?
This was the fuel behind this post! Be nice to see his problem solved.

;)
Pat

* There is a possibility he is not having any problems at all with extracts, only partials. If so, the answers given here would be particularly relevant.
 

Thirsty Boy

ICB - tight shorts and poor attitude. **** yeah!
Joined
21/5/06
Messages
4,544
Reaction score
106
[Looks like we posted within a minute of each other TB so you would have missed my last post. I think your above though answers my above! I think it does - the whole mash isn't 'heavy' enough?]

That's a mighty good and informative read Thirsty :super:

Good on ya! I now see what MHB meant by the 'heaviest' part of the mash and a lot of other things. Thanks a heap for the above!



The reason I asked was actually because a bloke on another forum is about to do his first BIAB. He started explaining his problem in this thread. Reading this tells me he can brew kits fine but is having problems any time he does an extract* or a partial. His questions continue from the above thread to this post tonight here.

I have been trying to work out his problem for a bit and then tonight he wrote...



This was the fuel behind this post! Be nice to see his problem solved.

;)
Pat

* There is a possibility he is not having any problems at all with extracts, only partials. If so, the answers given here would be particularly relevant.
OK - in reference to the posts you linked to above.

I'm not so sure that what everyone thinks is "small grain Particles" in BIAB wort actually is - of it will be to some extent, but I think that mostly it is in fact early formed break material that would normally be filtered out in the grain bed in a mash tun - but which just makes it to the boil in BIAB. So I don't personally think the brewer in question in those links is suffering from tannin extraction as his off flavour - otherwise nearly every BIAB brewer would.. its very common if not universal for BIAB worts to be much cloudier than mash tun worts, to a greater or lesser extend depending on your bag, but still more than trad brewing systems.

Filtering break - the trouble is, that anything fine enough to surface filter break material, will clog amazingly fast when it does - So bags, meshes, seives etc.. none of them work. They either clog, or the just let the break through. You can filter it out through a bed of whole hops... because whole hops form a depth rather than a surface filter. You can get the same through pellets, but its a bit more finicky and much slower. Which is why a lot of people use the whole whirlpool thing... if simply running the wort through a sieve/bag was a viable solution, everybody would be doing it that way.

What is the guys problem?? Well, you are never going to know until you taste his beer. He cant properly describe the taste,an you haven't tasted it. He needs to talk to local brewers who can taste his beer and talk it through with him. He says he gets the flavour in extract beers... so it isn't is mashing technique at all; and it isn't the break material thing either. It might be hops going into his fermenter that he doesn't like the resultant taste of - and running the wort through his bag could fix it if its that. If I were to take a guess - my guess is that he just doesn't like the taste of hops all that much, or at least not the varieties that he has been using - that he is quite sensitive to green beer flavours - or that he doesn't like the esters thrown by English yeasts.

Hope he solves his problem

TB
 

PistolPatch

Well-Known Member
Joined
29/11/05
Messages
2,717
Reaction score
44
Thanks for the above repy Thirtsty - scuse the slow reply :).

Yep it's hard to work out a person's problem long distance. Pretty frustrating.

He actually hasn't done a BIAB yet, only partials. I am hoping when he does a full BIAB his problem may mysteriously disappear.

We can only hope :).

Cheers and thanks again,
Pat

P.S. On the fine particle bit, my new bags seem to be finer than my old bag (drain slower) but the difference is hard to see to the naked eye. My worts turn out pretty clear and that's with pellets and no hop sock. I must dig out my old bag for a few brews and see if there is any difference in wort clarity on a side by side.
 

felten

Homebrew Conjecturist
Joined
13/5/09
Messages
2,536
Reaction score
45
I know what that guy is going through, I've had the same off flavour in my 2 latest brews as well, its bloody hard to describe what it tastes like to someone else, and even harder to pinpoint the cause of it.
 

PistolPatch

Well-Known Member
Joined
29/11/05
Messages
2,717
Reaction score
44
You poor bugger felten!

Some things are bloody hard to track down. For a strart, some flavours that you can't stand, other brewers may not even taste and vice versa. I had one for over two years which had me scratching my head. I coud never understand why when I brewed with someone else side by side I would get the flavour and they wouldn't. These brewers will tell you they are far less fastidious than I am. I even bought new fermenters. Grrrr.

Finally tracked the bastard down although I had to buy a telescopic mirror to see it. The problem was crap welds on some of my kegs.

Go figure :rolleyes:
 

Thirsty Boy

ICB - tight shorts and poor attitude. **** yeah!
Joined
21/5/06
Messages
4,544
Reaction score
106
P.S. On the fine particle bit, my new bags seem to be finer than my old bag (drain slower) but the difference is hard to see to the naked eye. My worts turn out pretty clear and that's with pellets and no hop sock. I must dig out my old bag for a few brews and see if there is any difference in wort clarity on a side by side.
Pellets and hop sock?? I'm a twee confused now. Do you mean pre or post boil wort? Cause I just assume post boil wort clarity - there's nothing about BIAB (or cloudy wort from any system) that inherently should lead to cloudy post boil wort. But pre-boil.. BIAB is certainly cloudier than any wort that's seen a proper grain bed on its way to the kettle.

Mind you, that's assuming normal BIAB bags.. The finer the bag, the clearer the wort will be - of course, as you've seen, that also means slower drainage.

I've been doing a bit of work recently with batches of GF beer, and batches of rice wine/rice beer - using quite tightly woven calico as filter bags for the mash/must/rice goo. Very clear wort comes out of the bag - it's just that you need to wait 10 or 12 hours for it to happen.

So like all things brewing, there is a compromise to be made... You can have BIAB wort that is as clear as HERMS wort... You just have to wait for it (oh, and the bag is bloody heavy too) if you wanted, you could use a very tight cloth and press the bag... Then it would absolutely be what it sort of is now - a mash filtration system
 

PistolPatch

Well-Known Member
Joined
29/11/05
Messages
2,717
Reaction score
44
LOL!

I actually meant pre and post-boil. Pre-boil I have hardly ever never noticed a problem with cloudiness and same with post-boil - even with pellet hops and no hop-sock.

I did go through about 6 months where there was a cloudiness problem but a fellow brewer over here, three-vessel, very experienced, lots of gold medals etc, also had the same problem. We never worked that one out. It just went away.

The only thing we didn't check on this were astrological tables :lol:
 

Thirsty Boy

ICB - tight shorts and poor attitude. **** yeah!
Joined
21/5/06
Messages
4,544
Reaction score
106
Huh - well there you go. Every BIAB wort I have ever seen has been very cloudy indeed (pre-boil). Guess like all things brewing, it kinda depends..... Not that it seems to make very much difference at all anyway.

Do me a favor can you? Next time you brew can you stir up your kettle pre-boil, and take a photo of a middy glass full of your pre-boil wort? Just so I can see what you mean. I will do the same (well, i'll try to remember) when we do our demo next Saturday, and the next time I brew on my own system. Might be an interesting tidbit of data or two to toss around the forums and draw invalid conclusions from :)

Cheers Pat

TB
 

PistolPatch

Well-Known Member
Joined
29/11/05
Messages
2,717
Reaction score
44
Sorry about the slow reply Thirsty - I have been under the pump :eek:

My major worry at the moment is when I can brew next. It's a long story. I was planning to brew over the Xmas break but now I have to do a major job :rolleyes:

I'm happy to photograph my pre-boil wort but I don't know how I can stir up a pre-boil wort any better than it is already stirred up by a near boil???

I also have no photographic skills so will probably let everyone down. Furthermore...

Pics of very clear BIAB wort can already be seen in the main BIAB thread though these could well have been before your time? I think though, from memory, that there would also be more recent pics? They are there but finding them will require a lot of searching/reading. If you can't find them there, I have posted one or two somewhere here already so search posts under my name.

What might also be interesting is if any non-BIAB brewers already have pics of their pre-boil clear wort after five minutes settling etc.

I doubt we would see any difference but what I doubt more is that we will ever see enough brewers willing to post such pics under the same circumstances for it to be in any way educational.

So, me posting one pic on one brew under no set standards (let alone recipe) is a totally pointless and ridiculous exercise. It will not prove a thing.

However, if say 20 brewers, BIAB and traditional, are willing to post their pics and we give them a standard, then we may have something.

If there is a difference, as you know, it really doesn't matter. What matters is the quality of the final beer. For now, no one has gone to any reasonable extent in determining if BIAB is better or worse than traditional.

The only time I have seen this was before your time. A search for "triangular" posts made under my name on this forum will give you that experiment and the result.

It favoured BIAB.

Dan, you are a bit of a scientist, so I think you'd agree that us home brewers are not great scientists. Personally, I am shocked by the myths that get perpetuated on a daily basis amongst our community. Personally, I don't like to encourage them.

I also don't want to spend my whole life refuting these myths. It's a dilemma.

I suppose anyone really interested in finding the truth should do some serious researching.

What else can they do?
 

argon

firmitas, utilitas, venustas
Joined
8/5/09
Messages
2,994
Reaction score
125
As far as preboil wort clarity is concerned... There is a difference between BiAB and 3V. I've done around 20+ BiABS and about 6 or 7 3V brews. I've not yet repeated any recipes in 3V and have no empirical evidence other than my own observations. However, from my experience it is irrefutable that 3V gives a clearer wort. Now whether this makes better beer I don't know. IMO quality is the same.
 

Thirsty Boy

ICB - tight shorts and poor attitude. **** yeah!
Joined
21/5/06
Messages
4,544
Reaction score
106
Pat - i just want to see a picture of your wort, because you say its pretty clear. I dont recall anybody else ever saying that about BIAB wort. Cloudy wort is one of the things that seems to (or used to) freak people out about the method. So i just wanted to see a picture to undestand whether we are simply defining "clear" in diffent ways. Maybe you call clear what i would look at and call sludge, or visa versa. Ergo, stir it up to make sure its homogenous, and take a photo of it in a middy glass (a nice readily available "standard" container) - i can do the same and we can compare photos. Dont need definqtive scientific results... Just a squizz. If the difference isn't enou to see in a photo of a middy glass, then its not enough to care about.

I've brewed on (or been present during brewing) on 5 or 6 different BIAB systems, and within those systems and my experiments, probably 6 or 7 different fabrics for the bag - the tighter the weave of the fabric, the clearer the wort, and the slower the bag drained - up to a tight calico that gave wort comparable to a mash tun based system, but that took multiple hours to drain out. For everything else, the wort has always been distinctly murkier than wort from a mash tun would be.

So i am really interested if you have a bag that is giving decent performance from a drainiage perspective, but is also giving fairly clear wort.. It would be the "ultimate" BIAB bag material.

Remember - i'm talking about pre-boil - post boil wort is usually just as clear as post boil wort from any other method of brewing.

No rush though... Just whenever you manage to squeeze in a brew.

Dont work too hard mate

Thristy
 

[email protected]

Simplicity is perfection
Joined
13/11/10
Messages
883
Reaction score
3
Interesting thread.

I have only done a few mashes BIAB, when i stired up the final wort it was what i would call fairly murky.
I was wondering at the time if this was right? Beer still turned out pretty good so i dont see it as a problem.

So could you filter the wort pre boil? just pour it through some sort of filter?

If so i would be interested to filter half the wort and do a side by side comparison.
 

argon

firmitas, utilitas, venustas
Joined
8/5/09
Messages
2,994
Reaction score
125
Interesting thread.

I have only done a few mashes BIAB, when i stired up the final wort it was what i would call fairly murky.
I was wondering at the time if this was right? Beer still turned out pretty good so i dont see it as a problem.

So could you filter the wort pre boil? just pour it through some sort of filter?

If so i would be interested to filter half the wort and do a side by side comparison.
IMO not worth filtering the "murky" wort... it all just settles out in the boil anyway. You just end up with a little bit more kettle trub. If it doesn't effect the flavour or yield there is no need to adjust anything.
 

Thirsty Boy

ICB - tight shorts and poor attitude. **** yeah!
Joined
21/5/06
Messages
4,544
Reaction score
106
Interesting thread.

I have only done a few mashes BIAB, when i stired up the final wort it was what i would call fairly murky.
I was wondering at the time if this was right? Beer still turned out pretty good so i dont see it as a problem.

So could you filter the wort pre boil? just pour it through some sort of filter?

If so i would be interested to filter half the wort and do a side by side comparison.
Well, yeah, you can. But anything that has made it through the bag, is more or less by defenition, so fine that you will need something very fine to filter it through, like a tightly woven cloth.... Which will take a long time. It is essentially just the same sort of time commitment as using a much finer cloth for your BIAB bag in the first place, except you have an extra step's worth of mucking about to do.
 

PistolPatch

Well-Known Member
Joined
29/11/05
Messages
2,717
Reaction score
44
No rush though... Just whenever you manage to squeeze in a brew.
Oh all right, I'll do it then :p . I am very worried about getting burnt fingys from the middy glass though :eek:.

I've never looked at it hot through a middy glass before so it might be interesting. All I know is when I do grab a pre-boil gravity reading, I grab a coffee mug, glad wrap it, chill it and then pour it into a hydro. Looks great :D.

Back to you later Thirsty ;)
 
Top