separating mash day and brew day

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jaydlaw

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Question,
I want to have a brew day tomorrow since I'll be working from home and will be able to keep an eye on things, but i do not want to keep an eye on things for over 2 hours. I was thinking that i could mash via BAIB today and leave the (extract, wort?) on covered on the stove to continue tomorrow with the actual brew process. has anyone done this? is there really any harm in it? i'm thinking i should be able to so this since i'll still need to boil tomorrow. If anyone has done this, let me know, also let me know why you wouldn't
 
I have considered this (for the same reason!) but not done it yet. I would probably seal and refrigerate the unboiled wort in the interim, although I could see why it would probably be unnecessary due to the impending boil.
 
I would recommend doing a quick pasteurization of the wort to kill off any bugs before you let it sit over night. Otherwise, just seal it up and it should be good.

Even without pasteurization, I highly doubt enough stuff would take hold in less than 24 hours to adversely affect the wort. I like playing it safe though, and it's relatively quick to pasteurize.
 
I've done this a lot. Just leave the lid on over night and you'll be fine, the boil will kill off anything that you need to worry about. I've also let my hops steep overnight as well,neither no ill effects.
 
I've done this a lot. Just leave the lid on over night and you'll be fine, the boil will kill off anything that you need to worry about. I've also let my hops steep overnight as well,neither no ill effects.
Are you guys leaving grains in overnight or removing them.
 
I left them in for the duration. Temp never dropped below 130°. I did taste it before the boil to make sure I wasn't wasting my time, but it was completely fine.
 
I leave the grains in. There is no bacteria that will "take hold" and survive a full boil...

no but there are bacteria that will take hold, and produce toxins that Will survive a full boil. Botulism comes to mind... Sure it's not likely but there only had to be a tiny amount of it to kill you. Not worth it when it will take like 10 mins longer to bring it up to pasteurize temps.
 
I leave the grains in. There is no bacteria that will "take hold" and survive a full boil...

Because this is the Internet, I want to clarify before we get started that I'm not being defense or attempting to attack another person's ideas. Just having a friendly debate/conversation. I always hate when stuff is perceived otherwise and kills any sort of discussion.

Grain is full of bacteria. Obviously bacteria won't survive the boil, but if lacto or some other bug takes hold in the mash, whatever they acid or other byproduct can affect the overall taste.

Sour mashing is all about leaving the grain alone in the mash. Unless you get the mash up to pasteurization temperature, you can't guarantee something won't happen to the wort in the mash.

I was pointing out the possible risk of leaving it alone and not pasteurizing the wort. Will something happen, who knows. Can something happen, possibly. At this point, I'm just providing data for OP to make an informed decision where they can weigh risks vs. benefits.

Plenty of people leave the mash overnight, without issues. I like to take precautions to prevent what I can control.

Excuse any typos/grammar issues, hate typing long posts on my phone.
 
Okay. Some good info here. For clarity, though, I think there are two different things being discussed?

There's actually mashing overnight, as-in, leaving the mash water in the mash-tun with the grain, and then there's leaving the sweet wort in the BK overnight after completing your mash out.

I just did the latter for the first time yesterday just because the brew day didn't work out the way I wanted, and I just ran out of time. I just put the cover on the BK and boiled the next day.

Everything seemed to be fine. Would anyone foresee any potential problems with that?

EDIT: never mind. Now that I actually read the thread again (DOH!) it's clear that pasteurization of the wort before leaving overnight is probably best practice. For a ten gallon batch though, that's definitely going to take a while, but I guess I could spend that time cleaning up.
 
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So out of curiosity, what are pasteurization temps and times? I can see an advantage to breaking up my brew day.
 
To each their own but here is what I have been doing for the past 8 years:

Mash at night about 9:00pm.

Batch sparge the following morning between 7:00am and 8:00am.

I personally have never had any offer flavors or issues but that doesn't mean you can't.

I started using this system due to a very busy life and kids. It was the best solution for me to cut time out of my brew day and keep the family happy and still brew beer.
 
I have overnight mashed (start late like 9 or 10 pm- get up next day like 6-7am).
Drain MLT, sparge if necessary and start boil.

you want to keep the temps up above 130* (I think) to avoid lacto and other issues. Usually with blankets and other warming things.
I usually do full volume mash, so the water volume helps keep it warm.
 
There is a time/temperature relationship for pasteurization with the approximate lower limit of 135 F. for at least 10 minutes.

Written by: The Editors of Encyclopædia Britannica

Pasteurization, heat-treatment process that destroys pathogenic microorganisms in certain foods and beverages. It is named for the French scientist Louis Pasteur, who in the 1860s demonstrated that abnormal fermentation of wine and beer could be prevented by heating the beverages to about 57° C (135° F) for a few minutes. Pasteurization of milk, widely practiced in several countries, notably the United States, requires temperatures of about 63° C (145° F) maintained for 30 minutes or, alternatively, heating to a higher temperature, 72° C (162° F), and holding for 15 seconds (and yet higher temperatures for shorter periods of time). The times and temperatures are those determined to be necessary to destroy the Mycobacterium tuberculosis and other more heat-resistant of the non-spore-forming, disease-causing microorganisms found in milk. The treatment also destroys most of the microorganisms that cause spoilage and so prolongs the storage time of food. (source: Encyclopedia Brittanica)

I don't think any of you mash a less than 135F. or for less than 10 minutes so your wort is pasteurized when the mash is over. If you keep the wort covered with a lid, it will cool slowly so there will be little time for any bacteria to do it's work of reproduction and spoilage and with the lid on very little bacteria will even get to the wort. In the morning you then heat the wort to a boil, killing off any bacteria that did get started. The only bacteria that can survive that it Botulin and then only as spores which require a higher temperature to kill, only achieved by boiling under pressure. Those spores can only multiply in a low acid environment so they won't reproduce in you beer
 
I do something like that quite often.

I will start the mash in the early evening after work. Once the mash is finished (i.e. drain, sparge, and drained again) I heat the wort in the boil kettle to 180 degrees F., put the lid on the kettle and shut every thing down. Bright and early the next morning, I finish the brewing process.

The longest I've delayed the boil was 12 hours but it should be OK for longer. I'd speculate that 24-36 hours with a decent sealing lid on the kettle shouldn't pose a problem.

While that final heating may not be technically necessary, it doesn't cost very much and gives me a little peace of mind.
 
I did something similar this past weekend, ran out of steam on a double-batch. Mashed, sparged, brought to a boil for 5 minutes, then covered the kettle. Resumed the boil about 20 hours later with no ill effects, kettle had dropped to about 85 F (mid sixties in the basement). I recirculated during the 5 minute boil to help ensure that my pump and lines wouldn't harbor anything overnight, and to minimize oxygen in those parts, too.
 
I know next time I am going to, I was up until like 4 am brewing. That includes cleanup but still. Well if I do on the stove again, I will separate the days
 
I did just that on my last brew. Didn't hurt a thing. Great beer loved by all.
 
With family now the priority in my life I have been looking at ways to cut up my brew days. It looks like this is the way to go.
 
Trying this tonight just started mashing at 152 going to let her sit all night I put two blankets and two heavy winter coats over kettle, will see what she's holding in the AM.
 
I wish I would, I am currently waiting for the wort to boil. I might end the day after the wort gets cold enough to put in the fridge after boil. But at that point i at as well get it down to pitching temp and finish up
 
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