Overnight Mashing

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permo

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I know this has been discussed over and over, but I wanted to start a new thread about overnight mashing so that we could get the most recent information and experience with the technique.

I recently mashed a kolsch overnight. Mashed in at 152 degrees at midnight and by 8:00 AM the next morning I was down to 135-140 depending on how deep in the mash the probe got. The beer is currently fermenting and appears to be just fine.

I mashed at 1.5 quarts per pound, and I think next time I will do 2.0 quarts per pound so that there is more residual heat.

All of my information says that as long as you don't fall below 130 degrees for a length of time, souring shouldn't be an issue. Either should an overly fermentable wort, as the enzyme activity and conversion all takes place in 90 minutes or less. After that, the wort is just waiting for you.

My gut feeling however, is that you do get a more fermentable wort, I have no data to back up that claim, but i just have a feeling. Long mash + thin mash = fermentable. So for my next overnight mash, I am picking a big beer. Likely a 1.070-1.075 IPA with about 18 pounds of grain.

I will let you all know how my first overnight mash turns out, but I think it is going to be great. Please post your experience or advice regarding this method. Thank you!!
 
interested.

but why? the mash is usually the shortest and easiest part of my brewday.

As a super busy, mutlitasking father of two girls under the age of 3, saving any amount of time is very valuable. This method allows me to heat my water and conduct my mash in peace, after the kids and SWMBO are in bed.

I also beleive that there is an inherent increase in your mash efficiency, so maybe adjust your recipe for a 3-5% increase. I overshot my gravity .08 points last time. Not that I am complainin.
 
Why not mash, collect runnings, and then let that sit overnight? Instead of the whole mash? One more step to get out of the way while the fam is asleep shortening your following day when they're awake.
 
Why not mash, collect runnings, and then let that sit overnight? Instead of the whole mash? One more step to get out of the way while the fam is asleep shortening your following day when they're awake.

Then the runnings would cool below 130 degrees and be way more susseptable to infection and wild yeast. If you mash overnight you are maintaining temp.
 
Then the runnings would cool below 130 degrees and be way more susseptable to infection and wild yeast. If you mash overnight you are maintaining temp.

sanitize two buckets, put wort in, put lid on. No different than when you're done and pitching yeast. no wild yeast will jump through the lid of a bucket. Done this twice myself with no issues. Besides, you're going to be boiling it all for an hour in the slight chance you pick up a bug or two. anyway.
 
permo - I definitely get the multitasking father thing. DOING IT!

With that said, I have myself wondered about overnight mashing. I have a good friend who's been doing overnight mashing for years with NO issues whatsoever. It's the only way he's done it and his beers are fantastic.

So, no first-hand experience....but I have tasted the results from overnight mashing and all is good!
 
As a super busy, mutlitasking father of two girls under the age of 3, saving any amount of time is very valuable. This method allows me to heat my water and conduct my mash in peace, after the kids and SWMBO are in bed.

I also beleive that there is an inherent increase in your mash efficiency, so maybe adjust your recipe for a 3-5% increase. I overshot my gravity .08 points last time. Not that I am complainin.

as another multitasking father of two sub-3 year olds, my kids wake up ~6am and are ready to rock, so that wouldn't work out for me at all.

anyway i wasn't trying to patronize your method, i was just curious. interested to see the outcome.
 
I know this has been discussed over and over, but I wanted to start a new thread about overnight mashing so that we could get the most recent information and experience with the technique.

Please post your experience or advice regarding this method. Thank you!!

Doesn't look like any of the posters so far are doing what you asked and posting THEIR experiences with doing it. ;)

You MAY have to rely on the similar threads box to get actual experiences.

I've never done it, but I know at least two different brewers who work at or own different LHBS in MI. who do it all the time.

Like you said it is better to mash overnight if you can keep the temps correct, than to collect the runnings and have them drop into lactose producing temps.

I know the folks who do it overnight, mention wrapping the cooler in a sleeping bag, and/or keeping it next to the furnace overnight. And they usually maintain their temps give or take a degree, so that's not an issue if you take proper precautions.

I think though the biggest would be not using too big a cooler for the amount of grain/water. Not using a 60 quart cooler for 10 or 12 pounds of grain. If all you have is a huge cooler, then maybe making some sort of insulating cap that you can shove into the cooler at the gainline. I've seen such caps mabe out of styrafoam wrapped in some sort of foodgrade plastic, maybe even saran wrap would do it.

I don't have anything else to share, not having done it myself, this is only second hand from folks I know who have been successful with it.

Hope this helps. :mug:
 
Revvy, I hear you on the cooler size. I have a 48 quart tun, and I think the kolsch grain bill was too small, still it worked out but I think filling the mash tun as much as possible would sure help.

Thank you for your input.
 
Revvy, I hear you on the cooler size. I have a 48 quart tun, and I think the kolsch grain bill was too small, still it worked out but I think filling the mash tun as much as possible would sure help.

Thank you for your input.

Hey I wonder if doing no-sparge overnight mashing would be a good idea? Just putting the entire volume of water in there. That would fill a bigger cooler and keep the deadspace to a min.

Also rather than saran wrap, wrapping the foam "cap" with tinfoil would be a workable solution.
 
Well I have a bit of experience with this by accident. A long day became longer than expected but I just had to brew no matter how tired I was. I did all the normal prep work & found myself doughing in at about midnight. I set my timer and laid down on the couch awaiting wake-up time with the timer. I awoke at 5:30 the next morning. By 6:30 I had my batch sparge going etc & was boiling before 7AM. For the record my mash tun is a 5 gal Makita cylindrical shaped cooler. This bier was a 10lb grain bill so the tun was 2/3rds or so full. My original mash temp was 153.5 when I checked the mash temp the next AM it was about 143. I got an extra 2-5% efficiency 86 or 87%. The bier gets moved to secondary in a few days, maybe even tomorrow if I need the fermenter for brewing. ;)

Sorry I don't have 'final results' type info, but it's practical info... I hope.

Schlante,
Phillip
 
I think mashing overnight would work fine, but I'd make some adjustments to account for the slightly higher efficiency and attenuation you'll most likely get. My experience tells me that enzymes keep working well past 90 min, but at a much reduced rate. I would guess that the temperature at the start of the mash will have a more pronounced effect on the final wort profile also.
 
Just an update, it has been nearly two weeks since I brewed a kolsch using the overnight mash. I set my target temp at 151, but morning it was between 135 and 145 degrees throughout the mashbed. Sparging, boiling etc..etc..all went just fine.

After two weeks with WLP029, the kolsch of 1.054 OG is down to 1.010 and the sample tastes stupendous. For beers where you are seeking full/super attenuation I think overnight mashing is a great idea, there is no sourness or off flavors in this beer...it tastes great and is very dry.

I am going to do my next india brown ale with overnight mashing and 2.0 quarts per pound of water......
 
I think though the biggest would be not using too big a cooler for the amount of grain/water. Not using a 60 quart cooler for 10 or 12 pounds of grain. If all you have is a huge cooler, then maybe making some sort of insulating cap that you can shove into the cooler at the gainline. I've seen such caps mabe out of styrafoam wrapped in some sort of foodgrade plastic, maybe even saran wrap would do it.

I don't have anything else to share, not having done it myself, this is only second hand from folks I know who have been successful with it.

Hope this helps. :mug:

Thanks Revvy, you inspired me to try killing my cooler dead space. The results were great. My cooler used to drop about 6 degrees an hour while half full of hot water, I even tried filling the lid with Great Stuff but that was a waste of time and money, the heat still escaped partly due to parts of the inside of the lid going straight to the top with no room for Great Stuff. I have no idea how quickly I lose temp during an actual mash because I've had a bit of trouble getting a consistent mash temp reading since I'm not recirculating (yet). I'm usually too busy or just frustrated :mad: to get that reading down hard. I'll work on it.

Now, it seems to lose 1 degree or possibly less per hour with just water inside:rockin:, I cut down a piece of thick R-30 fiberflass insulation and I had some clear fda approved bags I used to encase it. They weren't quite long enough so I put 3 bags on in alternating directions and taped the end. I just stuff it into my cooler when I have hot liquid inside and close the lid. I had to tape the lid shut because it was a bit too puffy. Could have probably used thinner insulation. When I'm ready to sparge I just pull it out, set it aside and rinse it off later. I'm going to try the same thing with a 10 gallon round cooler I bought yesterday, it might be easier to work with and more water proof since it will be less wide, my bags should fit better.

https://cdn.homebrewtalk.com/gallery/showgallery.php?cat=919

This thread also got me thinking that if I want to gear up for a multiple batch brew day, perhaps I could grind the grain and dough-in multiple coolers at the same time and just sparge them serially as I'm ready to start the next boil, so some mashes will be in the cooler a few hours longer. Shouldn't be much different than overnight and if I work quick it should be less time. I'd do the recipes with a higher mash temp first in the order.
 
. . . . . .
This thread also got me thinking that if I want to gear up for a multiple batch brew day, perhaps I could grind the grain and dough-in multiple coolers at the same time and just sparge them serially as I'm ready to start the next boil, so some mashes will be in the cooler a few hours longer. Shouldn't be much different than overnight and if I work quick it should be less time. I'd do the recipes with a higher mash temp first in the order.

Sure, then the next day you can boil all batches all day long and then do no chill overnight that night and be ready to ferment the next morning before your head explodes.:drunk: You might need to RDWHAWBOHB though, instead of just RDWHAHB.;)

Keep on brewing my friends:mug:
 
Anyone finding their beers to be watery? I mashed in on an IPA and immediately got a call from the LHBS, forgot I had to work that day. I went to work, came back and finished as normal. It was only in there for 5.5 hours and I lost 4 degrees. Tasted fine but was super thin. It was pretty much hop water. I added 8 oz of malto dextrin to the keg and the problem was instantly fixed.

I've never had this happen with any other beer and I've mashed at lower temps than this one.
 
I have done this technique for about 4 years now and I will continue to do it. I heat the appropriate amount of water to about 180 or so, mill the grains, dump the water into my retrofitted cooler (5 and 10 gallon, both with stainless steel braided water line and 1/4" ball valve), dump in the grains, stir to break up, cover, and let sit for about 12 hours or so. I started this in the winter months when brewing outside was down-right cold (I live in Wisconsin). Seeing as this worked out so well, I started doing it year-round. My brews have turned out great and I will continue to implement this technique. It saves me about 3 hours per brew session and I get better extraction.
 
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