overnight mash and keeping my cool

[JeffNYC]

I started my mash around 7:00 p.m., was a little light on my target temp at around 150F. Was around 130F (or so) 9:00 a.m. the next morning. Wort smelled fine, the spent grains smelled a bit sour so we'll see.

 

[wickman6]

My grains had a bit of something different than normal as well, maybe a bit sour? I think you wil be fine

 

[wickman6]

Stauffbier, good idea with the saran wrap! I'll give that a try next time for sure!

 

[Stauffbier]

Stauffbier, good idea with the saran wrap! I'll give that a try next time for sure!

I think it helps a tremendous amount!

 

[zyx345]

I've done this twice (RIS and IPA) and the results were very good. No sourness noted, however my RIS was a little thin in body but that may be due to my initial mash temp, 154. I overnight mash in a Coleman Xtreme cooler. For my next brew I'm planning on mashing in at around 158 to hopefully get a little more body.

 

[Hackwood]

My interest has been peaked. I'm going to have to give this a whirl. Thank you for the idea.

 

[wickman6]

Hackwood, give it a shot! I'm beginning to love this method. It really opens up more brew days for me, since i can split it up and it's very difficult for me to be able to nail down 8+ hrs to brew. Overnight mashing is great for anyone who finds themself in a restricted schedule. Great beer can still be crafted despite the traditional methods. So much is said about LETTING the beer work for you, but not too often can we HELP the beer work with us.

On a side note, after several batches, I have yet to brew a sour batch.

 

[Hackwood]

Niiiiiiiice! I'll probably employ this technique one of these times when I'm "on-call" and don't know If I'll have time or not.

 

[Spartan1979]

When I overnight mash, I wrap my MT in an old sleeping bag. Helps to keep the temp up.

 

[jerrodm]

Excellent thread--this is definitely something I'm going to look into. With this, every weekend could be a brew weekend, regardless of whether we're busy on Saturday or not!

 

[tre9er]

I've done exclusively overnight mashes and/or 3 hour mashes since I found out it was possible. Here are some basic findings through 5-6 batches:

Mashing at 153 will produce a beer so dry it will nearly hit 1.001 with an aggressive yeast like US-05. I got 95% attenuation on this PA.
Mashing at 156 produces a medium-to-dry bodied beer. This is kinda the cutoff point. Below this and you'll dry out from not denaturing enough beta.
Mashing at 158 is what you want for more full-bodied, malt-forward beers.

The last two mashes I did were in the 3 hour vicinity and my efficiency was the same, 80%, just like every brew I've done overnight/3+hours. My equipment did not change and previously I was in the low 70% range.

In my Coleman Xtreme 70qt cooler I lose about 10* overnight, ~8-9 hours. It keeps temps for the first few hours without much drop at all. It seems to lose temps near the end of the mash.

I detect nothing different about my beers, but you must adjust your mash temps accordingly, as per above or your experience. A recipe that calls for a 150 mash, do 153. 154, do 156. 156 do 158-160.

The Pale Ale I made that dried out to 1.001 was fantastic. It was dry (6%) but not alcoholic at all and the hops shone through wonderfully. It's in my recipes.

Lastly, this can be used as an "all day mash", too. Get up early, strike and dough-in, cover it and do what you gotta do. Come back at 4PM and finish up the sparge/boil while you have a few homebrews.

 

[Stauffbier]

Something else I'll add if it hasn't been mentioned... The less headspace you have in your MLT the better it maintains temp, so I mash thin. As much as 1.75q/lb. I've also done a "no sparge - over night mash", which turned out to be very good beer.

 

[tre9er]

Something else I'll add if it hasn't been mentioned... The less headspace you have in your MLT the better it maintains temp, so I mash thin. As much as 1.75q/lb. I've also done a "no sparge - over night mash", which turned out to be very good beer.

Yep. I play with mash ratio until I get the same strike and sparge volumes. Makes remembering my volumes easier, ie. I put 6.6g in the HLT for strike and 6.6g in the HLT for sparge. Simple. Usually I end up around 1.4-1.5g/lb.

I need to put foil over the top of my grist once and try that, too. I'm told that works wonders for heat retention.

 

[Heine81]

I wouldn't worry about infection pre-boil. Remember, the boiling process sterilizes everything.

When they brewed in the dark ages, they used pond water, and the brewing process "magically" made undrinkable water, drinkable.

I had a mess of a mash this weekend on a russian imperial stout. I kept sparging after i collected 5 gallons at 1.100. I collected another 4 gallons and brought to a boil (kill the enzymes) and then kept at room temp until I was ready the next day for a 60 minute boil. So far, so good (1.054 of the 2nd 4 gallons).

Hope that helps,

 

[JeffNYC]

Kegged my accidental overnight mash this morning, tasted fine. 1.012.

 

[Stauffbier]

I wouldn't worry about infection pre-boil. Remember, the boiling process sterilizes everything.

This is true, but if your mash drops below 140F lacto can set in and sour the wort. You can boil out the lacto, but you can't boil out the sourness...

 

[JeffNYC]

This was what I was worried about--I was well below 140F overnight. But while kegging tasted fine.

 

[tre9er]

This is true, but if your mash drops below 140F lacto can set in and sour the wort. You can boil out the lacto, but you can't boil out the sourness...

My 153 OvM ended up just a scosche above 140 by morning. It turned out fine, but again, I wouldn't want to get below that. Using a cooler and blankets is key. Higher water/grist ratio helps and I'm told putting foil over the grist does as well.

 

[Jem]

Has anyone mashed overnight with temp control? I'm thinking of trying with an electric biab set up and an auto stir, not sure of what temp to set paid at?

 

[Stauffbier]

Has anyone mashed overnight with temp control? I'm thinking of trying with an electric biab set up and an auto stir, not sure of what temp to set paid at?

Yeah, I've tried it. Well....... sort of. I used a heat blanket under my MLT! haha... It actually worked pretty good. It was winter, and my house gets cold (bad insulation - old house). It kept me above 146F after 12 hours with an initial mash temp of 155F.

The 140F thing is pretty much the "cut-off" point for the danger zone, but I'm sure it would be ok if it dropped below that if it were only for a short time.

 

[wickman6]

My first attempt dropped to 138 if I remember correctly. I have no idea how long it was that low, but I had no sourness in the finished beer. Obviously not ideal, but it worked out that time.

Thanks to a few great ideas from some of you, such as using foil/saran wrap to seal up the cooler and mashing a bit higher than recipe calls for I'm sure that 138 won't be an issue anymore.

 

[tre9er]

Mashing higher is a must. As I've mentioned, you won't completely denature all of the beta amylase, even in a higher mash, so as the temperature drops and alpha goes to sleep, beta will keep chewing up chains, resulting in a highly fermentable wort. Like I said, add at least 3 degrees to recipe mash temp.

 

[beerloaf]

I did a first time overnite mash with a 12 gal batch of Strawberry Blond. I did it because of time constraints more than anything. It was just easier to split the mashing on one day and the boiling the next morning. My temps dropped 14*F in about 10 hours. I was pretty happy with that. I ended up hitting my OG dead on and no issues followed as far as mash efficiency. Only issue I had was cooling 12 gal of boiling wort. That took for about 1.5 hours due to not having a CFC which I need to get. My immersion chiller is great for 5 gal batches but I need something better for 10+ gal brews.

beerloaf

 

[tre9er]

What temp did recipe dictate and what temp did you do?

 

[wickman6]

I'll be mashing in tonight, EdWort's Haus Pale ale. Gonna give it a shot at 158 and see where I get.

I brewed the same recipe last weekend mashing at 152 for an hour, so I'll have a good side by side comparison as to how the temps work differently based on mash time.

 

[Stauffbier]

I'll be mashing in tonight, EdWort's Haus Pale ale. Gonna give it a shot at 158 and see where I get.

I brewed the same recipe last weekend mashing at 152 for an hour, so I'll have a good side by side comparison as to how the temps work differently based on mash time.

I'll be very interested in hearing about the results. I almost did an overnight mash tonight, but then I got invited to the bar. So much for that idea...

 

[wickman6]

I'll be very interested in hearing about the results. I almost did an overnight mash tonight, but then I got invited to the bar. So much for that idea...

I hate when that happens...lol

I mashed at 157.4, close enough. Dropped to 145.7 in 6.5 hrs, used the saran wrap method this time coupled with blankets. I'm happy with that. Kitchen smelled glorious this morning!

I have access to some heavy duty plastic foam stuff that car bumpers are packaged in. I think I'm going to mahe a sleeve for the cooler that I can just slip over it. It would be reusable. I'll post pics once I get around to making it.

 

[tre9er]

making a muncher helles tonight/tomorrow, overnight mashing of course. im shooting for 157 tonight and hoping to attenuate from 1.051 to 1.012 or so. i might be upping my mash temps even more lately as ive had some dry beers even with the increased temps.

 

[BOBTHEukBREWER]

Set up two 250 watt light bulbs in reflectors and put them 12 inches away from either side of your mash tun. This will stop or minimise heat loss. If it results in a heat gain, so what? you will have at least an hour at 66 deg C then a slow rise to say 78 deg C - perfect, now sparge and get it boiling. If this is already covered in one of the 57 posts,,, sorry ! and sleep well......

 

[tre9er]

Set up two 250 watt light bulbs in reflectors and put them 12 inches away from either side of your mash tun. This will stop or minimise heat loss. If it results in a heat gain, so what? you will have at least an hour at 66 deg C then a slow rise to say 78 deg C - perfect, now sparge and get it boiling. If this is already covered in one of the 57 posts,,, sorry ! and sleep well......

I wonder how well this would work with a cooler, though. Perhaps if I built a foam-board cover (like a box with no lid) and put it over the mash tun with the light bulb(s) underneath, this might work. Interesting idea.