Using An Urn For Brew In A Bag - Tutorial

[Darren]

Brando,

I suspect you would be lowering you efficiency by lowering your BIAB into what would otherwise be higher gravity wort. BIABers need to consider how to "sparge" the "haggas". Perhaps a simple pour of boiled kettle water over the suspended bag would do?

Being positive I maintain that there are more effective and easier ways to do this.

cheers

Darren

 

[fergi]

I invariably use hot water out of the solar and often, this time of year, it is just about on strike temperature anyway. My old kid's sleeping bag I've had for 10 years and a chinese feather doonah keep the mash lagged efficiently enough for a 2 degree drop over 90 minutes so I have no need to apply heat, therefore the exposed element doesn't worry me.

bribie, do you have any concerns running hot water from a hot water supply considering whats probably at the bottom of your tank, eg sludge etc. just curious , might try that pre heat myself.

fergi

 

[brando]

Brando,

I suspect you would be lowering you efficiency by lowering your BIAB into what would otherwise be higher gravity wort. BIABers need to consider how to "sparge" the "haggas". Perhaps a simple pour of boiled kettle water over the suspended bag would do?

Being positive I maintain that there are more effective and easier ways to do this.

cheers

Darren

Darren, I'm ok with the efficiency, the concern is more about whether I might be extracting unwanted tannins this way.

 

[QldKev]

Darren, I'm ok with the efficiency, the concern is more about whether I might be extracting unwanted tannins this way.

If you are going to 80, and killing the heat for a sparge, all is ok.

QldKev

 

[manticle]

The photo shows bag lifted off the element of Birko urn after mash has been completed. Here I'm raising the temp from 65 to 80 degrees, to then lower the bag again for mashout then sparge. Usually takes about 10-15 mins to reach 80 degrees (which then drops back to about 77 degrees when bag lowered).

As can be seen, the bag is not fully out of the wort, and I'm wondering if I could be risking getting astringency from the contact at high temp.

Any thoughts?

I'm a bit confused as to your concerns.

Please clarify if I've misunderstood.

You sacch rest at 65 then remove the bag until you heat to 80 then dunk the bag back in. However part of the bag remains in the liquid during the heating and you're worried that that heat will make the grains release tannins? The dropping back of the bag lowers the temp to a range at which you're not concerned?

Have I got it right?

To my mind (and someone else may have a much better idea) I wouldn't worry too much. I use a tun for my sacch rests but my mashout temps are up around 90+ degrees and I have never been able to pick up any astringency.

The main question though is; have YOU noticed any?

If not then I wouldn't concern myself too much.

 

[under]

I didnt think a mash out was required for BIAB, neither a sparge.

 

[manticle]

According to many, mashout isn't required for homebrewing at all, whether BIAB or 3V.

 

[under]

The way I was looking to do it was-

- Use approx 2L less water in the mash
- No mashout. Just pull the bag out.
- Turn on burner and bring to a boil.
- Let grain bag drain over a pail.
- Heat up 2L of water to mashout temp
- When bag stops to a slow drip, pour the hot water all over the of the bag. Let drain.
- Add to boil.

 

[Darren]

Darren, I'm ok with the efficiency, the concern is more about whether I might be extracting unwanted tannins this way.

I would not worry about tannins unless you are "rinsing" too much..
Sitting "sugarless" grains in hot water would extract tannins but pouring hot water over a suspended BIAB would be very unlikely to extract excessive tannnins to cause problems

For your further information, decoctions (in a tun) requires of boiling of the grains. This process would extract heaps tannins if it is a problem. Additionally, tannins believe it or not also help with clarity of beer.


cheers

darren

 

[manticle]

Agree with the above. My experience is limited but I recently did my first decoction and despite finishing at 1008ish the beer is quite sweet. Definitely no tannins.

 

[Thirsty Boy]

re: the mashout in BIAB

Mashouts in "traditional" brewing are about fixing the fermentability profile, they probably aren't needed in most homebrew situations.

BIAB is a little different though!

In a more traditional homebrew set-up with either a batch or a fly sparge, temperature is added during the sparge to the grain bed, because the sparge water is quite a bit hotter than the mash temperature. This increase in temperature not only helps with reducing the viscosity of the wort, it helps with the process of rinsing the sugars out of the grain.

This doesn't happen in BIAB if you don't raise the temp... you are effectively lautering 10 or so degrees C below the temperature that all the other methods use... this reduces your efficiency. Raising the temp in a BIAB mash is less about "mashing out" than rising to "Sparge" temperature.

The other thing that people rarely consider, is that starch is not perfectly gelatinised at normal mash temperatures, a portion of it remains ungelatinised and therefore unconverted... raising the temperature of the grainbed during the mashout helps to gelatinise this remaining starch, where it can be dextrinised by the Alpha Amylase that survives for quite a while even at M/O temps and even partial saccharified. Enzymes might well be dying off at M/O temps, but the ones that are left are working at great speed because of the raised temperatures.

So in BIAB, gaining the maximum conversion efficiency from your mash is one of the ways that it "makes up" for the lack of a sparge step. With a fine crush, the high L:G ratio and a ramp to a mashout - the conversion efficiency will be pushing 100% in BIAB.

The other reason (apart from straight efficiency) that this might be important in BIAB - is because of BIABs cloudy wort. In a mash/lauter tun, recirculation and filtration through the grain bed allows much of any unconverted starch (present as small particles) to be trapped during the lautering process. In BIAB... a lot more stuff just falls through the cloth. If there is unconverted starch.. then there is a decent chance it will make it into your kettle, and a corresponding chance it might make it into you beer, where it could cause haze and stability problems. Raising to a M/O temp converts the starch and avoids this potential issue.

I personally don't think the way Brando does his mashout is the best way to do it... the temp change from the perspective of the majority of the grist is too sudden. I think that the bag should be left in place and the mash stirred while the requisite heat is added. Both the stirring and the ramp itself making the conversion process more effective. Dumping the grain bag and its load of (potentially) unconverted starch back into a pot of 80C water asks the process to happen in a bloody great hurry - starch takes a little time to be accessed, heated and gelatinised, the enzymes take a little time to convert it... if you ramp slowly, all the gelatinisation and conversion that is able to happen at the lower temperatures on the "way up" to M/O temp, has happened already, and its just mopping up that happens at the peak temp.

I've always advocated a M/O in BIAB - performed by adding heat and constantly stirring till you reach the rest temp, then just pull the bag out. It needs a shield over you element if you have an exposed electric element in either an urn or other sort of pot, and it needs a little effort. But for the above reasons, I believe that it is the "better" way to do it.

Sorry for (yet another) long post. I would say things more briefly if I knew how to explain them more simply.

Thirsty

PS - a sparge of any description is NOT needed in BIAB. You can do one if you like, but you should be getting perfectly good efficiency without one ... if you do a mashout anyway.

 

[RdeVjun]

A really informative post yet again, Thirsty! I had wondered about lifting, draining and then adding near- boiling water for sparge + mashout and what effect that might have on enzymes. It sounds like it is better to gradually raise the temperature of the mash rather than dumping a heap of heat in there with at least some portions of it being overheated and probably reducing or destroying their activity. I might get that round cake cooling rack out again and slip it under the bag so I can just apply some heat.

Many thanks indeed for clearing all that up! :icon_cheers:

Edit: Clarity.

 

[Bribie G]

TB
That's the best post I've read on the subject for ages - why didn't you tell me all that a year ago *******






I'll be brewing this afternoon if grains turn up and I'll try the temperature raise. Here's a piccie of a beer that has been 2 months in the bottle. It was gelatined and polyclared, tastes great but I reckon that just has to be a starch haze, :huh: plus I used a fair amount of rice, and mashed fairly low as I was looking for a drier beer.



And I totally agree with Darren for once believe it or not, about the tannins and the fact that the Germans and other decoction mashers have been boiling the crap out of grains for centuries, and produce fine beers that way.

 

[thanme]

Does any one have any success stories with BIAB in a 30L urn?? I want to move to BIAB, and have a 30L urn and want to give it a go before forking out for something bigger and better.
I read Thirsty Boys guide and it seems pretty straight forward.

 

[Bribie G]

If I had a 30 L urn I would personally adapt a method I used in the UK with a 'bruheat' electric boiler and do a 'two vessel' system. Basically you do a BIAB mash in the urn but with a 'thicker' mash. Hoist the bag and drain off the first runnings into a spare fermenter or even just a nappy bucket. Then heat some water to sparge temperature in the urn and dunk the bag to do a batch sparge. Hoist the bag, drain, squeeze, remove the bag, pour the first runnings back into the urn and away you go. The trick would be to try for around 28 litres and boil carefully at first.

I don't know if anyone is having luck with this method, maybe RdeVuyn would have some comments as he's a small batch guy.

 

[Thirsty Boy]

Rde Vjun is your man here - he is brewing full sized batches in small vessels.

So if you look at the guide I wrote (I know that will work) - Have read of Nick JDs post (here) about doing smaller batches in smaller vessels - And read of a few of Rde Vjun's posts (search em out, I know he posted a good description of his method once upon a time)

You will have seen a few variations of what to do with a smaller pot and have a few ideas about how to use yours.

Me personally - I would get some experience doing very simple, smaller AG batches via the "stock" no sparging no mucking about BIAB method, then have a go at a bigger batch as per my post - then a full size batch as per Rde Vjun's method.

Then, if you are bitten by the bug.. you can consider whether its worth your while investing in a bigger vessel (remember Urns are not the only choice... not even necessarily the best choice) to make your life simpler.

Oh and if you haven't already - make sure you have a bit of a read of at least the first few pages of the main "Guide to Brewing in a Bag" thread. Its a monster.. but if you wade through it, it will answer all your questions.

TB

 

[Bribie G]

TB is right about the urn not being the only or best choice. I chose to go 40L urn for ease of use and basically getting a 'turn key' brewery in a box - however I was talking to PistolPatch, one of the fathers of BIAB, at a case swap a couple of weeks ago and we both agreed "wouldn't it be great if they made a 50L urn" Amen.

BIAB itself has few restrictions - urn size is a vessel restriction, not a BIAB restriction, but it can be worked around.

 

[thanme]

Thanks

Sounds like I've got a bit of research to do! A smaller batch might be the go to start with. I'm more or less interested to get a feel for it, and see how I go with the process and how the beers go vs. my extract beers. I think I've got a good idea of the what and why of the whole thing..Just need to see if I can put it into practice! It'll also be interesting to see if I can live with having a half full fermenter

I met PistolPatch a few weeks ago, and he's been a fountain of advice, but moreso with larger batches, and he actually mentioned talking to you (Bribie) with respect to doing it in an urn And then I found this post. Good coincidence!

Is there any hard and fast rule about mash water vs. grain amount??

 

[Phoney]

PS - a sparge of any description is NOT needed in BIAB. You can do one if you like, but you should be getting perfectly good efficiency without one ... if you do a mashout anyway.

I never used to do a sparge with my BIAB, never had an issue with efficiency, but the last two batches I did just out interest. Put 2 litres less water into the mash, then poured 2 litres out of my kitchen kettle over the grains that was sitting in an empty bucket. I was suprised how much sweet wort was extracted came out of the bag when I squeezed it the second time!

Again, it could have been a complete waste of time and acheived nothing for my efficiency, but it does get a fair whack of trapped sugars out of the spent grain.

Is there any hard and fast rule about mash water vs. grain amount??

YES!

There's a spreadsheet that PistolPatch gave me that gives me the exact quantity of water to use. If you use a urn I cant recommend it highly enough!

 

[Thirsty Boy]

Oh there is no doubt that sparging will improve your efficiency - it absolutely will (up to a point) - its just that as you said, you don't need it to get decent efficiency.

If you want more efficiency - and you are willing to trade time and effort to get it... then sparge away. If you want to, I suggest a dunk sparge with 20-25% of your starting water as the most likely to do the job effectively but not require "big" pots to heat the water in.