Overnight mash

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hooper80

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Hi guys, just weighing up doin overnight mashes, the pros are all in favour of time saving, but what are the cons?
 
I know you will get a heap of "its a great idea" responses - it isn't!

Two main reasons.
First, It will change your mash profile. Especially as you aren't likely to be mashing out which ends most the enzyme activity. Say you mashed at 65-67oC amylase will keep chipping away at anything it can, there are also a bunch of different Proteases that can reduce your head building protein to peptides. You might like what happens but odds on the beer will lack body and probably head retention.
You won get the beer you planed.

Second is infection. If you have ever smelt expended grain a day or two after you have brewed you will know the pong I'm talking about. It's mostly Lactobacillus that isn't killed at mashing (or even mash-out) temperatures, the same bugs will be busy in your mash for the 8 or so hours its sitting in the tun. Sure you will kill the bacteria in the kettle but you cant boil out or breakdown the products produced by the bacteria.
It might not be as full-on revolting as soured mash grain, but there will be some in your beer and believe me it wont make your beer taste better.

If you are going to brew, do it properly and make great beer, its almost axiomatic but every shortcut, time, money saving idea I have ever heard of detracts from the beer quality.
Mark
 
Last edited:
I know you will get a heap of "its a great idea" responses - it isn't!

Two main reasons.
First, It will change your mash profile. Especially as you aren't likely to be mashing out which ends most the enzyme activity. Say you mashed at 65-67oC amylase will keep chipping away at anything it can, there are also a bunch of different Proteases that can reduce your head building protein to peptides. You might like what happens but odds on the beer will lack body and probably head retention.
You won get the beer you planed.

Second is infection. If you have ever smelt expended grain a day or two after you have brewed you will know the pong I'm talking about. It's mostly Lactobacillus that isn't killed at mashing (or even mash-out) temperatures, the same bugs will be busy in your mash for the 8 or so hours its sitting in the tun. Sure you will kill the bacteria in the kettle but you cant boil out or breakdown the products produced by the bacteria.
It might not be as full-on revolting as soured mash grain, but there will be some in your beer and believe me it wont make your beer taste better.

If you are going to brew, do it properly and make great beer, its almost axiomatic but every shortcut, time, money saving idea I have ever heard of detracts from the beer quality.
Mark

If you are able to program a mash out and hold it that temp for 6-7 hours after a 90 min mash would you expect to see the same degradation in body and head retention? can lacto develop at 75c?

or... could you mash out, remove the grain then hold the wort at mash out temps overnight and continue with the boil in the morning?
 
If you are able to program a mash out and hold it that temp for 6-7 hours after a 90 min mash would you expect to see the same degradation in body and head retention?
Perhaps not, I don't know exactly what would happen but suspect a 'Mash-Out" intended to stop enzyme activity would do just that. I am also fairly confident that 6-7hours at 80oC will extract a bunch of Tannin from the husks and do a bunch of other unpredictable things to your beer. If you have that sort of time/temperature control - why not program it to hold at 20oC for 6-7hours then ramp up to mash followed by mash-out...
can lacto develop at 75c?
**** yes...

or... could you mash out, remove the grain then hold the wort at mash out temps overnight and continue with the boil in the morning?

As above wouldn't address the infection issues.

Having used a Braumeister for years, I have tried cold mash-in, followed by hours of hold at ambient, then stepping up through mash to mash-out, worked OK. There was an old German method that did exactly this, mashing-in cold the night before. It has some advantages, full hydration of the grist, complete enzyme dissolution (going into solution) it also lets a couple of enzymes that normally don't come into play have a go. There are at least 20 enzymes that can be involved in mashing, most of them are denatured at lower temperatures than most people mash-in at (<55oC).
Truth is you actually get slightly better extraction efficiencies, but it is slower (1 brew/day) and costs a lot more in energy and works best tied into a decoction mash regime - not exactly a time/money saving alternative - in fact the reverse, more time consuming and expensive.
Mark
 
If you have that sort of time/temperature control - why not program it to hold at 20oC for 6-7hours then ramp up to mash followed by mash-out...

My herms ramps very slowly - I typically only use it to maintain mash temps and ramp with the assistance of a gas burner. I worry that if i tried this method the mash would be in the 30-50C period for way too long and lacto would likely be an issue.

long brew days aren't the worst thing in the world for me though....
yesterday my brew day went something like:

8:00 am - collect water and turn on herms
8:30-9:00 - took kids to kindy
9-9:45 - mill grain
9:45-10: mash in
10-1: went for a surf and had lunch
1-2: mash out and ramp to boil, filled some kegs from last batch
2-3: boil wort, and clean fermenters, and mash pipe
3 - 3:30- whirlpool hops
3:30 - removed hop bag, turned the chiller water on - went to pub
5:00 - returned from pub, sanitised fermenters and filled
5:30 - done (apart from cleaning which I left for today)

obviously thats a long day but I did have 3 hours of surfing and lunch plus an hour and a half at the pub in there while things looked after themselves.

Maybe just organising the water and milling the grain the night before and having the herms heat the water ready for a 6:30 am mash in would speed things up a lot rather than risk an overnight mash.
 
There is an interesting mash regime you could try.
Mash in at ambient, let it ramp to 80oC, if you are ramping at 0.5oC/minute (1/2oC/m) or so you will spend long enough in the activity range of each enzyme for it to do all of its work before it is denatured.
Remember all enzymes work at ambient (just slowly) they don't go from Off to No to Dead, more like starting slowly and getting faster and faster as they approach their individual activity peak, then fall over.

Its a really simple process if your heat input isn't too high it only requires limiting/stopping at 80oC.
From say 20-80oC (a change of 60oC) at 0.5oC/m is only 120 minutes.
You could easily mash-in the night before and set a timer to fire up the HERMS a couple of hours before you are ready to run off to the kettle.
Mark
 
I know you will get a heap of "its a great idea" responses - it isn't!

Two main reasons.
First, It will change your mash profile. Especially as you aren't likely to be mashing out which ends most the enzyme activity. Say you mashed at 65-67oC amylase will keep chipping away at anything it can, there are also a bunch of different Proteases that can reduce your head building protein to peptides. You might like what happens but odds on the beer will lack body and probably head retention.
You won get the beer you planed.

Second is infection. If you have ever smelt expended grain a day or two after you have brewed you will know the pong I'm talking about. It's mostly Lactobacillus that isn't killed at mashing (or even mash-out) temperatures, the same bugs will be busy in your mash for the 8 or so hours its sitting in the tun. Sure you will kill the bacteria in the kettle but you cant boil out or breakdown the products produced by the bacteria.
It might not be as full-on revolting as soured mash grain, but there will be some in your beer and believe me it wont make your beer taste better.

If you are going to brew, do it properly and make great beer, its almost axiomatic but every shortcut, time, money saving idea I have ever heard of detracts from the beer quality.
Mark


Mark how about bringing to the boil for say 5 minutes and then leaving overnight ?
 
Is that long enough to sterilise the wort?
Can you guarantee something else wont get in while its sitting there.

Sorry there are no better ways than mash/boil/chill/pitch yeast, everything else costs you something.
Whether or not that price is one you are willing to pay is a personal decision - just don't forget you are paying.

Again if the time is that important to you, just be aware that the hotter somethin is the faster chemical reactions happen - so if its sitting around hot watch for reactions like oxidisation, and you energy bill will be higher.
Mark
 
I wouldn't mash overnight, how much time could you save really? If I want a smooth and quick brewday, the grain is weighed and milled, the Kettle (I BIAB) is filled with the strike water, everything is ready and layed out. I get up at 6am and turn her on, then have brekky, then mash in. As easy as it's going to get.
 
There is an interesting mash regime you could try.
Mash in at ambient, let it ramp to 80oC, if you are ramping at 0.5oC/minute (1/2oC/m) or so you will spend long enough in the activity range of each enzyme for it to do all of its work before it is denatured.
Remember all enzymes work at ambient (just slowly) they don't go from Off to No to Dead, more like starting slowly and getting faster and faster as they approach their individual activity peak, then fall over.

Its a really simple process if your heat input isn't too high it only requires limiting/stopping at 80oC.
From say 20-80oC (a change of 60oC) at 0.5oC/m is only 120 minutes.
You could easily mash-in the night before and set a timer to fire up the HERMS a couple of hours before you are ready to run off to the kettle.
Mark

I have read that method before - would be the ideal way to do it, but my system ramps way slower than that. The herms tube has a 2200W element (can't really pump any more amps through the old house wiring), and my normal brew length is either 80L or 120L, so it is good at maintaining mash temp but as far as ramping is concerned i think 60C rise with the mash would take 5 or 6 hours of which 2 hours would be between 30 and 50 which i imagine would be worse than leaving it at mash temp for 5 or 6 hours.

All good - next brew i'm just going to turn on the herms to heat the strike water and mill my grain before going to bed and that will at least save a couple of hours.
 
I wouldn't mash overnight, how much time could you save really? If I want a smooth and quick brewday, the grain is weighed and milled, the Kettle (I BIAB) is filled with the strike water, everything is ready and layed out. I get up at 6am and turn her on, then have brekky, then mash in. As easy as it's going to get.

I've been overnight mashing for about 3yrs now.

An overnight mash works a treat with the Braumeister. Mash in @ 9pm at 20c for 3hrs, let it run through its my mash profile and then running at 76c for 3hrs, this has her beeping around 6amish. A no chill will be done within 2.5hrs, a chilled beer add 45mins to that.

The outcome is always a higher attenuated beer due to the 60c to 64c period when raising to 66c, so hitting a 1012 FG is often landing around 1009 which suits the styles I make.

Now its not always the way and will say, a single step infusion then raise to mash out, boiled, chilled and yeast added, those beers are the best.
 

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