Preparing for a sleepover

I have been doing overnight mashes for all of my beers the last 9 months. It is awesome! I mash in after the kids go to bed for the night, wrap the MLT (cooler) in a heated throw blanket, then wrap that in an old sleeping bag. Takes about an hour to set up, heat water, dough in, check temps, cover up, fill kettle with sparge water. Sit down and have a beer, watch a show, hang with the wifey. Wake up with the kids in the morning, start heating the sparge water, check temps in the MLT. Start the runoff, batch sparge, start boil and proceed as normal. I have been shooting for about 4*F higher than a normal mash temp for the style as the 10 hour mash drops around 10-12*F. I haven't used this technique for beers requiring super high mash temps for higher FG beers. I did do a 160*F for 2 beers @ 1.046, FG @ 1.008 done with Brett B and Biere de Garde. I hit 82% mash eff every time, I get 75-78% on typical 60 minute mashes. I got all my pointers from jlpred55.

 

I haven't found the idea of an overnight mash thins the body much at all. I have done 5-6 mashes this way on a couple different styles. I have found that a 154F mash temp, seems to come out with the same attenuation and body regardless of overnight or tradition 60min mash and right into the brew kettle. So what I am saying is don't worry about mashing out before bed. Set it up. Insulate it really well. Go to bed.

 

In my experience, an overnight mash just adds time since you're starting the sparge water from cold when you get back to the mash tun. For me the best overnight split has been to get the mash and sparge done...then start the boil the next day. Maybe you don't have enough time the night before, but this is an idea based on my experience.

 

Also, when I did do overnight mashes I never noticed my beers thinning out. Conversion is done well before the temps really drop out.

 

Longer mash times do result in a more fermentable wort (fermentability is a little different than full conversion), but I don't think I have ever seen data for times beyond 280 minutes. It may well be that severely diminishing returns kick in not long after (or even before) that. If you look at Kai Troester's data, you could interpret it to say that it's basically flat after 90 minutes (under his experimental conditions).

 

Overnight mash doesn't kill head retention?

 

Correct. I go all night long baby.

 

Nope. I have a bottled CAP that was overnighted, head lasts forever, thick, creamy, holds the bottle cap.

 

First ever overnighter was a split ferment G Pils and Saison. Pils took 2nd in BJCP comp. Neither the GPils or CAP have any off flavors or bad remarks related to mashing/body.

 

Do it all the time, no issues yet.

 

My last 40 batches or so have all been overnight mashes and I've never noticed anything wrong with the results that could be ascribed to that process. I find it very convenient.

 

Great thread. Good technique for balancing homebrew hobby with time management concerns. I could see myself doing this sometime.

 

Never noticed diminished head with overnight mash either.

Another option which I have done a few times is to set up the mash early before work.
Then start heating sparge water when I get home, sparge and start the boil. Depending on how much sleep you like to get v. how long your work day is (door to door) one or the other will be a short mash.

 

No mash out at night. The only difference is to let the first mash go 6 hours instead of 60 minutes.

I recommend against a mashout before the overnight mash. I am not as successful at maintaining 152 degrees on my mash overnight. My temps drop 10 degrees or more. I don't get the same volume of wort when I drain the first runnings because the grain bed/wort is colder. The wort doesn't drain as freely. I make up for it on the mashout because of the higher temperature of the wort/grain bed.

 

i've been mashing this way for more batches than I can count. I do them both in the morning before I go to work and boil when I get home or on the weekend overnight. I've used no sparge mashes and batch sparge mashes and never mashed out. No head issues, no over attenuation issues, no souring, nothing really negative I can find yet, other than the occasional slow sparge. I only used to do it for beers where I desired attenution at higher levels but I recently did a few test batches that I attempted to manipulate the attenution using the mash and it worked nicely. Before I never worried about it, beacuse I knew right where it was going to attenuate (which is very much the same as a my traditonal 60 min mashes, IME). There really isn't a lot of magic in this, just think of it as a break in the process.

The only tips I would suggest are: rehashing some suggestions

• Tracking the temp drops each time so you can adjust based on the those. I don't prefer to drop below 140F for too long.
• Mashing in a temp controlled environment to eliminate the outside impact of a hot or cold garage or basement
• Pre-heat the tun well and wrap it up well in a high quality sleeping bag or heated blankets
• Not mashing over more than 10-12 hours (I've found after that I can't maintain temps to prevent souring, eventually)
• Knowing the mash is going to maintain inconsistent temps. The outside will be much cooler than the middle.
• Have a beer while setting up and mashing in and coffee while sparging and boiling.

 

It's a technique that I use frequently - sometimes for time management, but more often for increased fermentability. No mash out. 20-ish lbs of grain loses about 6F over nine hours in my 10 gal Rubbermaid cylindrical cooler. I cover the lid with pot holders or a blanket to keep the heat in (the lid is not insulated).

The first time I did it was for time. It was a Cream Ale that went from 1.060 to 1.002 (75% two-row, 25% flaked Maize, WLP-080). While I never researched an authoritative explanation for the insane attenuation, the consensus among the more seasoned members of my brew club was that the sugars continued to break down as the temp dropped. It was as if I had done a more traditional (60 min) mash at 148F.

Since then, I usually include a healthy dose of Crystal malts when using the technique - maybe 10% - and I tend to limit it to beers where the base malt is straight two-row, in which the malt character is not critical. It's also good for big beers, IMO, since this will dry them out a bit over a conventional mash.

FWIW, it's also a good technique when you lack confidence in your ability to get the mash temp just right (go a little high, then let it drift down to the desired mash temp).

 

One other tip that I left out. Try to get the mash tun as full as possible before leaving it to rest. I don't typically use this technique if I am doing a simple 5 gallon batch. Then again, I don't typically do a simple 5 gallon batch anymore. I will mash for 10 gallons and either split boil or split ferment. I have even mashed the base grains and added specialty malts to split kettles for a steep before boiling.