Rack For Biab - Any Ideas?

[bignath]

Is it a bad thing to use an aluminium colander?

Have been thinking of BIAB racks the last few days, and came across some really good designs in local shops. I can get a good size aluminium one that will cover my element idea i want to do, but not sure if the material will be problematic.

Dont want to start an aluminium vs stainless debate as theres enough of them already, but what about using both at the same time? Does using the two metals together make one leach stuff out more?

 

[Camo1234]

Also I need to get this straight.... for a mashout - after your "rest" (mash) period you raise the temp for say 10 minutes to say 75C. Is this 10 minutes once temp is at 75C or is 10 minutes from the time you start adding heat?

Amber - Did you ever get your answer to this question? I am keen to know this as well... Only up to my 5th BIAB and haven't really got my head around whether I should do my 75min mash and start heating again for 10 mins or heat till I get to 75 and leave for 10 mins at 75? (stirring the whole time as well?)

I also have a Crown, concealed element so it usualy takes the whole 10 mins to get anywhere near the 75C!

Cheers, Camo

 

[pk.sax]

The purpose of the mashout is to a) Denature the enzymes and lock in the sugar profile & B) make the mash runnier.

point a) would make me think that the 10 minutes is to ensure all the enzymes are killed & to ensure all of it has reached that temp so there aren't any dense colder spots left over.

 

[iralosavic]

Enzyme denaturing is not an instantaneous process, so time must be given to allow the remaining starch to gelatinise. I'm not sure on the scientific/mathematical justification for "10 minutes", but it seems to be widely accepted as... long enough, I guess. I'm fairly sure I've read a study (a long time ago) that mentioned that higher mash-out temperatures can convert more of the remaining starches to sugars, but this does not necessarily imply a superior mash efficiency as the final gravity will end up higher due to the presence of more of the less fermentable sugars that are released at higher temperatures in the mash. I could be remembering wrong though.

 

[Bribie G]

Any sugars converted at higher temperatures would be mostly unfermentable, as they would be in the form of dextrins.

 

[pk.sax]

http://braukaiser.com/blog/blog/2008/05/05...uring-mash-out/

This seems to contradict what I regurgiated above

 

[stux]

http://braukaiser.com/blog/blog/2008/05/05...uring-mash-out/

This seems to contradict what I regurgiated above

Ahhhh, but it does make the mash runnier which is the primary benefit in BIAB

 

[pk.sax]

Another multiple personality disorder!?

 

[iralosavic]

haha Stux. Yes, the reduction in wort viscosity is the most significant/obvious benefit of mash-out for me...

 

[Amber Fluid]

Amber - Did you ever get your answer to this question? I am keen to know this as well... Only up to my 5th BIAB and haven't really got my head around whether I should do my 75min mash and start heating again for 10 mins or heat till I get to 75 and leave for 10 mins at 75? (stirring the whole time as well?)

I also have a Crown, concealed element so it usualy takes the whole 10 mins to get anywhere near the 75C!

Cheers, Camo

No, I didn't get an answer and it appears no answer forthcoming either. Makes me wonder if people actually know or are they guessing what to do and don't want to say in case they are proven wrong...... Nevertheless, what I have been doing, and not to say it is the right thing to do, is raising the bag off the bottom and applying heat at 10 minutes before mash time has finished. This usually gets me close to 75C then I leave it at 75C for another 10 minutes.

I have no idea if this is the right procedure but seems to be working ok for me and I am happy to read of a better process so I can employ.

 

[iralosavic]

I answered the question, allbeit in my own fart-arsed manner!

Enzyme denaturing is not an instantaneous process, so time must be given to allow the remaining starch to gelatinise. I'm not sure on the scientific/mathematical justification for "10 minutes", but it seems to be widely accepted as... long enough, I guess.

To make it as clear as possible: yes, mash-out involves a 10 minute rest. The time it takes to rise the temperature to your target mash-out temp would vary from one person/system to another, so specifying a ramping length in a recipe would be a rather misleading thing to do.

 

[Thirsty Boy]

The purpose of the mashout is to a) Denature the enzymes and lock in the sugar profile & B) make the mash runnier.

point a) would make me think that the 10 minutes is to ensure all the enzymes are killed & to ensure all of it has reached that temp so there aren't any dense colder spots left over.

no its not - not in BIAB anyway.

mashout in BIAB is about 2 things. Efficiency and starch conversion.

Starch Conversion - BIAB is not the ideal mash environment - people can bleat and moan all they like, but it isn't. BIAB also misses the vorlauff step that a normal mash/lauter tun has and finally BIAB radically disturbs the mash bed during the lauter process.

All of which means, that there is a reasonable chance of there being some unconverted starch and that any unconverted starch in the mash (and if you mention an idodine test at this point, you dont actually know how they work) is far more likely to end up in the boil kettle with a BIAB brew than it would be with a mash/lauter tun brew.

So - you intensify your mash and make sure you convert all your starch. The way you do it, is by increasing the temperature of the mash beyond the gelatinisation point of even the really resistant starches, by stirring to access the physically trapped and isolated starches and by doing this gradually over a period of time to give the remaining enzymes (which will be working overtime in the increased temperature environment) time to convert the starches as they are gelatinised.

Take 10 minutes or so to constantly stir your mash as you raise it to a temperature of 76-78 and something along the lines of all your starches will be liberated, just in time for the last gasp of the dying enzymes to convert them to sugars.

This doesn't require any rest period at the "mashout" temperature - there is no point to a rest. There is a point to constant stirring and a gradual raise in temperature. So any mashout you might do that doesn't involve both these things is more or less pointless and I would just skip it.

Efficiency - well, your mash is more intensive, you convert more starch to more sugar, and your lauter is at a "normal" lauter temperature.... it all works just a little better than if you dont do it and I would expect a bump in efficiency (measured in the kettle) of say 3-5% by doing a mash out vs just. pulling the bag at the end of a 60 min mash. Less return for effort if you normally mash for 90min, but still a little.

Do you "need" to do it?? Hell no! But its something that I think constitutes good brewing practise and will make it more likely that you will end up with fault free beer that resembles the beer you were trying to make.

60 min mash
Raise gradually with constant stirring to 76-78
Pull Bag

Adds maybe 5 mins to your brew day and in return you get a modest efficiency bump and a tick in a box for consistent quality brewing practise.

TB

 

[Nick JD]

I use my trademarked Incoction technique.

At the end of the mash bring the whole grain bill to a rapid boil for half an hour. Then raise the bag.

 

[Mikedub]

thats Gold Thirsty Boy

Up to now Ive hoisted the bag, raised temp to 76, bag back in for 10 min, could it be my recent spate of higher than expected FGs is because a more dextrinous starch conversion is occurring at 76 than need be?

 

[Bribie G]

Thirsty Boy's post reinforces the desirability of using a rack - particularly in an electric urn. I generally do a 62 / 71 / 78 stepped mash and when ramping between the steps I constantly pump with the paint stirrer with a stick thermometer in the other hand. The final raise from 71 to mashout only takes a few minutes and the pumping ensures constant contact between any starches left, and enzymes.

The old hoist and heat then dunk and stir method was a pain, and the rack was the best $15 I'd spent in a long time.

 

[bcp]

Take 10 minutes or so to constantly stir your mash as you raise it to a temperature of 76-78 and something along the lines of all your starches will be liberated, just in time for the last gasp of the dying enzymes to convert them to sugars.

This doesn't require any rest period at the "mashout" temperature - there is no point to a rest. There is a point to constant stirring and a gradual raise in temperature. So any mashout you might do that doesn't involve both these things is more or less pointless and I would just skip it.


60 min mash
Raise gradually with constant stirring to 76-78
Pull Bag

Thanks for the clarity on the BIAB mashout process. My process was close, but it clearly helps to understand precisely what needs to be achieved and the approximate time required to achieve it. I think that with my urn it takes about 10 minutes to get to mashout temps anyway just by turning it on, but I will be checking. Which would mean no additional time required.

So by extension, a potential fault with BIAB might be in some cases excessive starches in the boil. I should know but can't remember - too much starch can lead to haze... and what other faults?

 

[Bribie G]

bcp makes a point that is often overlooked, because BIAB is a single vessel process you have to heat that vessel anyway to bring to the boil. So (provided you have a rack or some means of not scorching the bag) the mashout comes for free and you'd be nuts not to do it. The only penalty is having to stir for 5 or 10 minutes.

TB, is the higher liquor to grain ratio the reason that some starches might get missed in the thinner, less intensive enzyme soup? So if there's an easy way of preparing some more liquor (in my case in a pail with the OTS heater) would there be advantages in mashing at a LG ratio more like 3V and using a quantity of hot liquor into the pot to raise to mashout temperature? Quite easy to calculate with one of the online "mixing" calculators. Maybe BS has one?

Also I thought that vorlauf was more to do with preparing the bed for sparging after the mashout?

 

[Nick JD]

TB, any conversions that would be happening when raising to mashout temp with the grain in, will still be happening when raising to that temp without the grain.

 

[stux]

No, I didn't get an answer and it appears no answer forthcoming either. Makes me wonder if people actually know or are they guessing what to do and don't want to say in case they are proven wrong...... Nevertheless, what I have been doing, and not to say it is the right thing to do, is raising the bag off the bottom and applying heat at 10 minutes before mash time has finished. This usually gets me close to 75C then I leave it at 75C for another 10 minutes.

I have no idea if this is the right procedure but seems to be working ok for me and I am happy to read of a better process so I can employ.

Possibly the best answer you're going to get

http://www.aussiehomebrewer.com/forum/inde...mp;#entry811242

 

[stux]

Possibly the best answer you're going to get

http://www.aussiehomebrewer.com/forum/inde...mp;#entry811242

When I mashout, I don't raise my bag, because raising the bag causes a huge heat loss when I lower the bag again. Rather I agitate the mash in place with a large potato masher as I raise the temperature.

I generally raise the temperature slowly over 7 minutes or so, then let rest for 3 minutes and raise. Sometimes I let it rest for ten minutes.