Over night mashing

[davew]

Has anybody tried this technique?

Basically get your mash on before going to bed then sparge and boil the next morning.

[Bribie]

Used to be Dave Line's favourite instructions in his books: "Mash 2 hours or overnight"

I sometimes do it, I get home from work around 11pm and have put on a brew, lagged the urn (I do BIAB) and it's still around 50 degrees by morning, then get up for the brew day, heat it up to mash out temperature, drain the wort and carry on as normal. In fact I was going to do it last night but I don't have any grain milled and the neighbours wouldn't appreciate a milling session at midnight.

[Madbrewer]

I have indeed done this, but not recently. The beers turned out fine as far as I remember. If I wanted to 'split' the brewday now though I'd probably try mashign and sparging one day and boiling the next purely to ensure the brew didn't become too dry (alcholic). I am sure the 77 - 80c sparge liqor 'stops' the enzymes from over converting - although I don't remember having a problem with this before I might have been pushing my luck. Anyway splitting it this way is something I'd consider!

[dcq1974]

I regularly mash overnight and do not get any problems. Efficiency increases from 80% to 90% usually when I mash in overnight - not that efficiency should be deemed more important than great tasting ale

[RichardG]

Personally I mash and sparge as per normal, then leave in the boiler over-night and carry on first thing. Of course I need to heat the boiler basically from cold, but given I have a family to consider, this works for me and means I can pretty much brew as an when I want without upsetting anyone.

[Rick_UK]

Never tried this but sounds interesting.

Currently I always mash sparge and boil in the evening leave to cool overnight in a cold bath and pitch the yeast the following day. This keeps the impact on child/wife care to a minimum.

Rick

[jmc]

Hi Davew

I've done this a couple of times and to be honest the brew tasted fine.

I did it for the same reason as others probably do; trying to juggle desire to brew and also keep family / SWMBO happy, and also sometimes its useful (to me) to be able to fit in a split brew (Friday evening + Sat morning) when I'm planning to do other stuff Sat pm.

Unfortunately I think that even with a really well insulated mashtun you're still likely to get a temp drop of 10C+ overnight, so if you want a beer with residual sweetness or heavier body it might be a problem.

I'd be interested if others with more experience would confirm / deny this, as I've avoided this method recently as I thought it would benefit the brew if I could control mash temp better.

ATB John

[pantsmachine]

I've done it a few times and get more enjoyment out of a 2 day brew session than i do out of a 6 hour cram it all in. The beers outstanding, no downside!

[dean_wales]

I would be interested to know the effects of overnight mashing on flavour profiles.

If you mashed at 68 but then left it over night would you get the body and sweetness remaining from the mash or would the hours at low 60s and 50s undo this and leave you with a drier beer?

+ 1 for splitting brew days for working dads!

Thanks,

Dean.

[Wolfy]

if there is any basis to the idea of a 'mash out' (raising the grain bed temperature enough to denature the enzymes and 'lock' the selected wort profile), then over-night mashing where the enzymes can munch away to their hearts content (before it gets too cold for them) may well change the profile of the wort that is produced. I guess it would work fine for some beers, but you might have problems with others.

[jmc]

Hi Wolfy
Thanks for your post. I agree with you.

Next time I do this, if I want to try to retain some residual sweetness in the beer I may try and use a yeast to help out. Maybe Fullers / WLP002?

Alternatively it might be possible to use the overnight mash to one's advantage.
It might be interesting to try this with a beer you wanted to be really dry.

Lots of things to try, and so few brewdays...

ATB John

[Steve B]

I quite often mash overnight with no problems. If I was to be Hyper picky perhaps the overnight sparged results are a little drier, but thats purely subjective. Starting the mash on the higher temerature side might deal with that, though.

[staplefordbill]

I've done it a couple of times with good results. I make the sparge water a little hotter (around 85c) than normal as the mash loses a lot of heat overnight.

[sladeywadey]

I'm considering this too due to family duties etc. I have a herms system and I wonder if my little 12v pump will be up to being left on for 6-7 hours recicrculating!