All-Grain Delayed Brewing

Due to increasing time constraints, I was wondering if I could break up my regular brewing day into two days. I presume I would extract the wort from the Mash and instead of immediately boiling, I would store in a container or in the brew pot overnight.
I would then brew the following night, or within 2-3 days after extracting wort.

Are there any problems with this procedure? I enjoy All-Grain and do not want to go back to extract.

It's called overnight mashing. Some people will tell you it works great, but the only time I've tried it, I ended up with a wort that was terribly thin and lacking character. I think that the problem is that you give too much time for beta amylase to work.

You will need to refrigerate it immediatly or you will likely end up with a sour mash.

Tony above is also correct, although most people mash 1 hour or less, conversion from complex to simple sugars continues for hours, making your mash very fermentable.

Raise the temperature of the wort post mash to sanitize it and stop the enzymes and it would likely hold over fairly well...bring it to a near boil and lid the kettle I would imagine it would stay for a coupole days??? YMMV

I went ahead and did the overnight mash. I figured that if I have to bring the wort up to boiling prior to letting it sit overnight or storing in a cold environment, then what's the point in not waiting another hour to complete the process.

With the overnight mash I lost more heat than I thought I would, even while double wrapping the cooler with thick blankets. Temperature reading after 9 hours was about 135, so I think I'm ok with not having a sour mash.
Batch sparged as I normally do.

Received better efficiency than I thought I would, ~83%

Will know in several weeks how it turned out. But wow. Surprisingly simple. Almost eliminates the timing for the mash process in a brewing period, since the mashing is done during dead-time.

I have done this on a few batches and they turned out great, but I do a Mashout before sparging to disable the enzymes. Add boiling water and bring Mash up to 168-170 for ten minutes and that will help with the vorlauf and keep the wort stable.

Subscribed. I would love to hear others experiences with an overnight mash because the idea has always appealed to me. Anyone else experience such awesome efficiency?

Though it wasn't the wort, I have cleaned out the grains from my tun into another container and forgot to take it out of the garage. Of course it still had a lot of water, so I guess it's still somewhat wort, just never boiled. I was amazed how quickly it soured, it was in the garage for just a day before the stench started. At no point was I tempted to drink it. I have time constraints, too, but I don't think I'm ready to try the overnighter myself. But, I'm interested in knowing if it worked out for you!

Thanks,
Isaac

I've tried an overnight mash once. I mashed in high (158*F) so that by the time it was all said and done I had plenty of unfermentable sugars AND a very fermentable wort. My mash held for 12 hours and only dropped to 143*F.. I wrapped seran wrap around the cooler where the lid meets the cooler so the heat would stay contained better. I also wrapped the cooler in about 3 blankets. The batch I made was a 2Row/cascade smash that I primed with german black forest honey, and it is awesome! It tastes great, has perfect head retention, plenty of body and not at all dry...

I have done a few overnight mashes and I love how I can split the brewday in two. I've got maybe 20 all-grain brews under my belt and one of the best beers I ever brewed was a 10 hour mash though I don't know if it was attributable to the length of the mash or other variables. I've brewed this past Saturday and did a 12 hour mash (man were those grains cooked!). I ended up with 89% efficiency. I tasted the beer today and had no sour taste. My advice is to start the mash in the high 150s or low 160s to counteract the thinness. Also if you want some body go with a lower attenuating yeast. I wouldn't recommend going 2-3 days though unless you have a fridge but if you do throw in a Campden tablet or two and it should keep the bad stuff from getting out of hand.

I just heard on an old BN Podcast that I was listening to that this technique is very popular in Australia. As appose to force cooling their wort, they allow the wort to cool over night in a sealed plastic box (of some sort, I havnt seen these myself) and sanitize all of the openings. I believe they put their hop additions directly into the box as well and let them sit in the wort as it cools. Once it has cooled to fermentation temp they pitch their yeast.

They do this because of water restrictions that exist in drier parts of the country that prevent them from using the excess amounts of water that immersion chillers require.

I believe they call the technique "cubing"

Any Aussies out there to confirm this?

As I go thru my notes I wanted to put some additional info out there as I more likely won't remember in the next few weeks.
When I found out I lost a lot of temp, I batch sparged with 190 temp to get the grain bed back up to 170 and rested for 30 minutes.
I also used Campden tablets for the first time - 1/4 tablet for mash and 1/4 tablet for sparge.
Great krausen and all the signs of healthy fermentation so far (used a starter that was probably bigger than necessary).

I plan to let this sit for 3 weeks, and as it is an IPA, will then dry hop for 7 days. I've recently been carbonating my kegs with sugar so will wait another 2 weeks afterwards. Will post details when I sample in 2 weeks

Transferring into the secondary today. Sampled - got down to 1.008 FG. Taste....the same if not better than my previous IPA. Could be the difference in hops I used on this batch, but there is no damage from using overnight mash. I'm setting up to do another overnight mash tonight.
I may add more water for the overnight mash as my last notes indicate the grains soaked up lots of water. But I may just leave it as-is by bringing the mash up to 170F tomorrow, holding for 10 minutes to wake everything back up, then vorlauf...and will sparge as usual.

Hope to maintain steady temp loss - will try the saran wrap idea as mentioned earlier...or maybe even aluminum foil to reflect the heat back into the tun?

My 2nd try may fall apart and turn out to be liquid fertilizer, but overnight mash seems to be viable. I really want to try this beer, so I may forgo the natural carb and use CO-2.

Thanks for the updates, they're helpful to me!

Rather than let it mash all night, mash for an hour, then add boiling water while stirring to bring up to 168-170 that stops the enzymes. I vorlauf, then slowly fly sparge and fill up my pale ale pail to the rim with the wort. Let that sit covered overnight and siphon into your brew kettle or use a bottling pail and drain into your boiling kettle. I have noticed I get a super clear wort as overnight there is a settling of flour that sneaks through.

After a few days of fermenting I can see clearly through the carboy and have produced my clearest beers this way. Let them sit in the primary three to six weeks and siphon to Keg or bottling bucket and bottle.

Griff777 said:

Rather than let it mash all night, mash for an hour, then add boiling water while stirring to bring up to 168-170 that stops the enzymes. I vorlauf, then slowly fly sparge and fill up my pale ale pail to the rim with the wort. Let that sit covered overnight and siphon into your brew kettle or use a bottling pail and drain into your boiling kettle. I have noticed I get a super clear wort as overnight there is a settling of flour that sneaks through.

After a few days of fermenting I can see clearly through the carboy and have produced my clearest beers this way. Let them sit in the primary three to six weeks and siphon to Keg or bottling bucket and bottle.

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If I understanding this correctly, you are basically mashing out with full 6.26-6.5 Gal but holding the wort in the mash tun overnight? When it comes down to boiling the batch, it's already waiting...interesting. I didn't know how well that worked. Would it be the same process for batch sparge? After one hour, vorlauf, then bring volume of water into mash tun holding temps of 170-180? My mash tun can certainly hold this volume.

I am concerned about temp loss and conversion.

Why not runoff into the kettle the same night and proceed with the boiling the following day?

OG2620 said:

Why not runoff into the kettle the same night and proceed with the boiling the following day?

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From what I've read, transferring to the brew kettle right after mashing and letting it sit a few hours (temp loss) will tend to sour the wort. If there was a great, convenient way to insulate the brew kettle to maintain a temperature that will not sour the wort, then yes, you could transfer to brew kettle. Otherwise, I think the simplest way is to leave in the insulated mash tun.

Not an expert on this method...just trying to rehash what I've read.

Catnip_X07 said:

From what I've read, transferring to the brew kettle right after mashing and letting it sit a few hours (temp loss) will tend to sour the wort. If there was a great, convenient way to insulate the brew kettle to maintain a temperature that will not sour the wort, then yes, you could transfer to brew kettle. Otherwise, I think the simplest way is to leave in the insulated mash tun.

Not an expert on this method...just trying to rehash what I've read.

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Well, I have successfully performed that procedure without any souring of the wort. I ran off into the kettle at about 9pm when I realized that it was too cold to achieve a boil, and proceeded to continue with my brewing at about noon the next day when the temperature was more favorable. The batch was an Imperial Irish Red Ale with mostly late hop additions. I actually just recently received a positive review from that batch.

If you could provide a link to what you've read, I'd be very interested. If not, what are the factors that are creating the sour wort? Surely not heat loss alone.

Catnip_X07 said:

If I understanding this correctly, you are basically mashing out with full 6.26-6.5 Gal but holding the wort in the mash tun overnight? When it comes down to boiling the batch, it's already waiting...interesting. I didn't know how well that worked. Would it be the same process for batch sparge? After one hour, vorlauf, then bring volume of water into mash tun holding temps of 170-180? My mash tun can certainly hold this volume.

I am concerned about temp loss and conversion.

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You can batch sparge or fly sparge, just make sure you bring the wort up to 168 to 170 with your first infusion of water.(usually takes at least two gallons of boiling to get up to 168) Then, stir, let it sit and begin sparging by either method. I drain the tun into my bottling bucket(with spigot) and fill it up to my preboil goal, which is usually 6.5 gallons. Snap shut the lid, and lift that back to my countertop with spigot overhanging. In the morning, slowly drain using spigot and tubing to boil kettle. I was surprised by all the additional riffraff that settled out of the wort overnight. That's why I don't drain into the kettle directly. The beers using this method have been clear, and no bad tastes whatsoever. I am using nine to eleven pound grain bills.

The purpose of the mashout is to deactivate the conversion process so it doesn't continue overnight. I guess using this method you could be a little sloppier on the vorlaufing and draining of the runnings as any particles that sneak to the bottling bucket will settle out over night. I do vorlauf till the runnings are clear, about two gallons.

I just re read your post and I am not talking about leaving the mash overnight, just leaving the sparged wort overnight, once you have your pre boil volume.

Most people don't have enough room in their mash tun to add all the water and leave it there.

passedpawn said:

Tony above is also correct, although most people mash 1 hour or less, conversion from complex to simple sugars continues for hours, making your mash very fermentable.

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This is NOT true. The enzyme that is responsible for converting sugars denatures in about 120 minutes in 130* water. Overnight mashing will not lead to super dry beers or super fermentable beers or even very high efficiency. Maybe a couple points above normal, but that's all.

I've been overnight mashing for about a year now. I moved away from a HERMS system and started doing cheap 'n easy overnight mashes. I have not experienced sour mashes, thin beers or any loss or gain in efficiency.

I usually start on Friday nite. I setup my equipment, measure out my grain and mill. Heat up my strike water and dough in. I use a 100qt Igloo Max Cold and wrap it in 3 moving blankets. I usually see a 7 degree drop in temp over 6ish hours.

The next morning I drain the tun, batch sparge as normal and start the boil. I'm usually cleaned up and pitched by 9AM.