Mashing overnight

[youreds91]

I've done my first 2 AG brews that went better than I could have imagined. The only downside is the missus who's hassling me to finish DIY jobs, my excuse being lack of time & then I spend a whole day brewing.
I read on another thread about mashing overnight. So my plan would be to get my grain bill ready & do the mash late on, then get up very early & sparge & boil, hopefully being all done after breakfast, giving her all day to hassle me.

Any downside to an overnight mash?

CD.

[maxashton]

Several of our members do it. I've never done it myself, but its supposed to be good.

[Gurgeh]

I would say that you are likely to get a very attenuable wort, very little dextrins and a risk of a lack of body, due to the mash losing temperature over such a period.

if you are able to maintain the temp perfectly then no problem.

FWIW, I brewed 10 gallons in 4 1/2 hours last night - 6pm til 10.30pm I see no reason to have a >60 min mash or >60min boil

[Aleman]

I see no reason to have a >60 min mash or >60min boil

No there is absolutely no reason to use a 3 hour mash or 3 hour boil. Those brewers in the 1830's didn't have a clue about brewing at all

There are quite valid reasons for longer that 60 minutes for the mash and boil Mash wise if you mash at say 70C to produce sweet dextrins, you mash longer to allow the amylase enzymes to work on the wort to produce the most fermentable wort for that mash temp . .. stopping the mash early would produce a beer with a high FG. If you have a lot of adjuncts again you will need to mash longer, although you might have passed the Starch End Point, you could well have enough dextrins in there to produce an underattenuative wort.

Boiling longer than 60 minutes, will give more caramelisation, essential in a scotch ale. If brewing Barley wines, you are only likely to get a wort of 1.080 out of the mash (for a first wort), that needs to be concentrated before you add the hops, Hop isomerisation takes longer in High gravity worts, so you either need more hops (unbalancing the hop flavour profile) or boil longer. With low calcium levels in my liquor I find that I do not get a good hot break after 60 minutes and have to boil for that extra 30 minutes or I end up with a hazy beer.

[hoppingMad]

I would say that you are likely to get a very attenuable wort, very little dextrins and a risk of a lack of body, due to the mash losing temperature over such a period.

if you are able to maintain the temp perfectly then no problem.

FWIW, I brewed 10 gallons in 4 1/2 hours last night - 6pm til 10.30pm I see no reason to have a >60 min mash or >60min boil

I agree with Gurgeh. If you want a highly attenuable wort than you will probably get one mashing overnight.
However as the mash temp drops, you may be entering the realms of "ideal" for bacteria to start work. But as mentioned above, a late night mash-in followed by an early start and you should be fine.
You may consider building an insulation box to help keep your mash temp above the "risk" level. I made a simple one from 50mm thick polystyrene glued together with gorilla glue, in which my mash cooler sits with no airspace around and a tight fitting lid. Just permits a higher degree of heat insulation.

[hoppingMad]

Those brewers in the 1830's didn't have a clue about brewing at all

and I've often wondered just what their beer must have tasted like for just that reason ...

[youreds91]

Right, I've only just popped my AG cherry & thought I knew most terms but..

If you want a highly attenuable wort

Attenuable?

CD

[NzDan1]

I would say that you are likely to get a very attenuable wort, very little dextrins and a risk of a lack of body, due to the mash losing temperature over such a period.

if you are able to maintain the temp perfectly then no problem.

FWIW, I brewed 10 gallons in 4 1/2 hours last night - 6pm til 10.30pm I see no reason to have a >60 min mash or >60min boil

I agree with Gurgeh. If you want a highly attenuable wort than you will probably get one mashing overnight.
However as the mash temp drops, you may be entering the realms of "ideal" for bacteria to start work. But as mentioned above, a late night mash-in followed by an early start and you should be fine.
You may consider building an insulation box to help keep your mash temp above the "risk" level. I made a simple one from 50mm thick polystyrene glued together with gorilla glue, in which my mash cooler sits with no airspace around and a tight fitting lid. Just permits a higher degree of heat insulation.

A fellow Nz brewer has cut a peice of polystyrene that fits in the mashtun and basically sits on top of the mash, temperature drop has gone from a few degrees per hour to less than 1 degree celsius loss per hour.

[Jim]

Right, I've only just popped my AG cherry & thought I knew most terms but..

If you want a highly attenuable wort

Attenuable?

CD

Very simply, wort contains 2 types of sugar - maltose and dextrose. Brewer's yeast ferments maltose very easily, but dextrose with great difficulty.

Typical ale wort has 75% maltose and 25% dextrose, so when you ferment it with brewer's yeast, it will ferment the maltose, but most of the dextrose will be left (this is good because it gives the beer body and mouthfeel). So in a typical wort, you will be left with 25% or so of the original sugar even after fermenation is complete.

If you have a wort that has, say, 90% maltose and 10% dextrose, it will ferment right down to 10% of residual sugar. The process of the yeast converting sugar into alcohol is called 'attenuation', so such a wort is said to be highly 'attenuative' (or attenuable).

[Aleman]

Very simply, wort contains 2 types of sugar - maltose and dextrose. Brewer's yeast ferments maltose very easily, but dextrose with great difficulty.

Dextrins, Jim, Dextrins!! Dextrose is one of the sterioisomers of glucose - dextrorotatory glucose, and the only form that can be used in glycolysis

Sorry about attenuable, I just sort of made it up on the spur of the moment, for some reason my brain was not fully engaged I meant attenuative

[Jim]

Very simply, wort contains 2 types of sugar - maltose and dextrose. Brewer's yeast ferments maltose very easily, but dextrose with great difficulty.

Dextrins, Jim, Dextrins!! Dextrose is one of the sterioisomers of glucose - dextrorotatory glucose, and the only form that can be used in glycolysis

Sorry about attenuable, I just sort of made it up on the spur of the moment, for some reason my brain was not fully engaged I meant attenuative

I nearly put dextrins, but I made the assumption that the term meant a collection of different variations of dextrose, so I put that to keep things simple . I must not assume again!

[Aleman]

I nearly put dextrins, but I made the assumption that the term meant a collection of different variations of dextrose

Generally the term dextrins means any chain of sugars that is more that 4 units in length (although the actual number is in debate ).

Monosaccharides - Single sugar units - Glucose, Fructose, galactose
Disaccharides - Two Sugar units - Maltose, Sucrose
Trisacchcarides - Three Sugar Units - Maltotriose
- Four Sugar Units - Maltotetrose
Dextrins - These could include maltotetrose - depending on definition
Starch

[bluesboy]

I have mashed many times overnight (up to 18 hours) You need very good insulation on the mash tun, I lose about 10 degrees in 12 hours from about 75 to 65 deg celsius. I believe if you go below about 55 there is a chance of infection, but I have not had any problems. Saves you time and is excellent for strong beers.

Bluesboy

[Madbrewer]

I have mashed many times overnight (up to 18 hours) You need very good insulation on the mash tun, I lose about 10 degrees in 12 hours from about 75 to 65 deg celsius. I believe if you go below about 55 there is a chance of infection, but I have not had any problems. Saves you time and is excellent for strong beers.

Bluesboy

I've done 7 hours a few times and it probably did hit 55c (or lower maybe)
I'm not sure the drink was too low in dextrins at all.
The infection thing - would depend how long you left it as you are goign to boil it anyway. My advice is to try it and see how you get on, that's what I did. I don't do it now for other reasons.

[youreds91]

Typical ale wort has 75% maltose and 25% dextrose, so when you ferment it with brewer's yeast, it will ferment the maltose, but most of the dextrose will be left (this is good because it gives the beer body and mouthfeel). So in a typical wort, you will be left with 25% or so of the original sugar even after fermenation is complete.

If you have a wort that has, say, 90% maltose and 10% dextrose, it will ferment right down to 10% of residual sugar. The process of the yeast converting sugar into alcohol is called 'attenuation', so such a wort is said to be highly 'attenuative' (or attenuable)

Thanks for such a concise explanation.
So with more sugar turned to alcohol, the resulting brew would be lower in carbs?