mash timings breakdown (for school night BIAB)

[buckerooni]

hi all,

I'm using the school night brewing idea where it's a 30 mash/30 min boil but am interested if the 30 min mash includes the mashout out to 78c. Should the timings be like this (for example):

0. strike water at ~69c
1. mash in, sustain temp at 67c for 30 mins
2. start mash-out, raise temp to 78c (takes ~15 mins to get to 78c)
3. lift bag out, bring to boil
4. total of steps 1 to 4 = 45 mins

Is this a 45 min mash (mash-in to mash-out) or a 30 min mash with mash out?!

Also, do you typically hold it at 78 for a period of time? I'm sure it depends on style and characteristics but if a recipe doesn't specify what is the generic BIAB bash for a pale ale/IPA?

 

[anthonyUK]

Has anyone had success with a 30min BIAB mash?
I have read a number of times that for BIAB (full volume mashing) to ensure complete mash conversion do a full 90 mins.
30 mins sounds too short and consider for 3V you have more mash time due to the time taken to sparge etc.

 

[manticle]

30 min high mash works well for lower alc beers where you still want body and flavour but lower alcohol. I do it for dark milds.
Not sure why biab would require a longer mash than other wort production methods. The higher liquor ratio should increase conversion efficiency if anything.

Also most modern modified malts shouldn't require 90 mins unless something else is wrong.
Nothing bad about doing one if it gets results you are after but equally nothing wrong with 30 to get specific results you want. A mash can be tweaked according to desired outcome.

 

[[email protected]]

Get a tincture of iodine or use betadine at a pinch (I have used this) and do a starch conversion test. Take a small amount of wort and put it on a white plate. Add a drop of iodine. If it is purple you need to leave it for longer. If it is brown you are good to go and ramp to mash out. It shouldn't be guess work. Each malt will have different diastatic power and heat liable emzymes.

 

[buckerooni]

Very interesting abc, this seems like a great test when mash timeframe is a factor.

Next question, if the starch has converted, what is the advantage of mashing out to a higher temp? I assume the test is indicating there is no more starch to convert, so pulling the bag out (squeeze/drain etc) and commencing the boil is the next logical step? It's been mentioned this doesn't indicate the status of dextrines/proteins/lipids but I haven't looked into their specific impact on the beer.

From what I've read the mash-out effectively creates a more fluid beer that should be free of starch haze (no mention of a taste impact).

So, if I can either do:
- 30 min mash at stable temp (i.e. 67c)
- 15 min, then raise to 78c over the next 15 minutes
but I think I might go somewhere inbetween:
- 20 min mash, raise to 78c, then remove bag (~35 mins in total) and commence the boil

and once done, give the brew club a sip and see what the consensus is...

Anything else that I should be concerned about?

 

[[email protected]]

You are right the iodine starch test doesn't test for dextrines etc as these are not starches! At amylase rests, proteinases are pretty much denatured. To be honest at homebrewer level you don't even need the mash out step as you are getting your wort up to boil quickly - think a commercial Brewer's timeframe is a lot longer in sparging, getting to boil etc hence more the need to lockin the carbohydrate profile. There are a lot of commercial Brewers who don't mash out due to equipment limitations. If you really want to lower viscosity of the carbohydrates heat your biab to 76-80 degC and drain. I often skip the mash out step with BIAB as the burner is on full as soon as I lift the bag.

 

[stux]

In BIAB you pretty much get the mashout step for free.

The theory is that

1) it allows any lazy conversion to get a wriggle on as your ramp the temp towards mashout
2) it reduces the viscosity of the mash liquor, which assists in draining
3) since you were ramping anyway towards boil, there's no time impact, so its a win/win

After your mash is finished (for me at 90 mins) then just ramp to 78C, then *immediately* pull the bag and keep ramping towards boil.

You do not need to dwell at mashout temp with BIAB, you're not really trying to stop conversion as you would be during a normal lauter, and your bag might take 10 minutes to drain anyway, which if it all works well, should mean you're approaching the boil as you're done.

I let the bag drain for the first half of the boil, since its suspended anyway.


The trick of course is to ramp with your bag in place. I just use a cake rack on the bottom and agitate the mash with my (potato) masher as I'm ramping

 

[buckerooni]

Thanks stux, makes sense. I'm not seeing any overwhelming reason to extend my mash past 20 mins before I raise the temp and pull out the bag at around 78c - which should give me around 35 mins of mash time all up. As long as I hit my numbers.

The starch test seems more appropriate for my purposes, and faster than taking a gravity reading and also seems a better test for the circumstances.

As I'm only on my 8th odd BIAB the mission to squeeze time out for the school night brew is turning out to be a great learning experience. - thanks ABC and Stux.

It will all come out in the glass I guess and may have to re-adjust timings according to issues discovered.

 

[stux]

Yes, if you're going for such a short mash, I would definately do a conversion test before mashout, and I'd do the mashout, since its free

 

[Lemon]

What I have done in this vein, is to dough in at room temp, ramp at 1 degree per minute, to mash temp. Iodine test - not fully converted, rest at mash temp for 39 min, iodine test, all good,
. Then ramp up to boil non stop, pulling the bag at 78 ish.
It does make a different beer to an isothermal mash, which I did side by side with same beer.

From memory it saved me 30 mins. Not really worth the stress. Given it requires a bit of alert monitoring.

Lemon


Edited , fat fingers

 

[stm]

Stux, that's an excellent summary and explanation in your earlier post. It's what I do also and seems to make sense (and there is no time penalty, as you point out - you just gotta stand there and stir for 20 minutes or so).