Mash First, Boil Later

[nicklawmusic]

I'm planning on doing a Mini-BIAB on my stove top and wondered whether the following would be feasible:

Could you bring your water to temp, do your mash, remove and squeeze after the mash is complete and then put the lid on and leave the wort, boiling it + hop additions several hours later?

Just wondering whether I could do the first part in the day and second part at night due to childcare and stuff (so I'm not having a super late evening).

 

[aeviaanah]

Sure I don't see why not.

It may be beneficial to siphon off the top of the sediment that will form from sitting.


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[jtratcliff]

You may want to mash-out to denature the enzymes, otherwise you might end up quite a bit drier than you were expecting.

 

[nicklawmusic]

But it's not unreasonable?

 

[zoonose]

But it's not unreasonable?

It's fine. Sometimes I start the mash right before I go to bed, and finish in the morning.

 

[TexasWine]

So glad you asked this question. Today I was wondering the exact same thing.

 

[tjpfeister]

On a larger scale, I just held wort produced one night for 24 hours in a temp controlled kettle until I could boil it the following night. I'm not crazy about doing this on such a timeframe as it does darken the wort a bit, but ultimately it works fine and more importantly, works around schedule conflicts. (In my case, I had 18 days to produce and serve the beer, so I had to do it with whatever spare time I had)

So yeah, +1 to doing it with a mashout step

 

[RM-MN]

On a larger scale, I just held wort produced one night for 24 hours in a temp controlled kettle until I could boil it the following night. I'm not crazy about doing this on such a timeframe as it does darken the wort a bit, but ultimately it works fine and more importantly, works around schedule conflicts. (In my case, I had 18 days to produce and serve the beer, so I had to do it with whatever spare time I had)

So yeah, +1 to doing it with a mashout step

Some of us are experimenting with short mashes and no chill and have found that we can have complete conversion in 20 minutes or less and by doing a no chill and dumping the hot wort into a fermenter bucket can be done and cleaned up in less than 2 1/2 hours. That makes an evening brew session more feasible. Don't try the no chill with a carboy unless you let it sit in the boil kettle with a lid on until it is cool. Hot wort will destroy a carboy.

 

[geoffey]

If you do this you may want to consider heating your wort up to 180 for 20 min at the end of the mash, especially if you plan on leaving a significant amount of time between your mash and boil (more than a couple hours). This will kill off any unwanted bugs and keep you from producing a sour wort.


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[nicklawmusic]

Surely, if I'm doing a full 60 minute boil later that will kill off any bugs won't it?

 

[wilserbrewer]

Surely, if I'm doing a full 60 minute boil later that will kill off any bugs won't it?

Yes, it surely will kill the bugs present at that time. The catch is that if lacto bugs have taken hold, they will create a souring that the boil will not remove.

I would try and raise the temp after the mash to say 175, lid the kettle and resume within 24 hrs.

 

[nicklawmusic]

I'm resuming 5 hours later with the boil. How long do I need to hold the temperature at 175 for?

 

[geoffey]

Surely, if I'm doing a full 60 minute boil later that will kill off any bugs won't it?

Absolutely it will, but I'm suggesting you kill them off before they have a chance to spoil your brew. If Lactobacillus (which is found naturally on grain) has a chance to get working it can produce a sour wort before you start your boil, and you can't boil-off the sour taste.

Others can comment on how long it may take these bugs to produce any noticeable sourness, perhaps wort sitting out at under 180 degrees for two hours isn't much of a risk. But I figure why take the chance if it's easy to heat that wort up to 180?

I can tell you from experience that leaving it overnight is enough time to spoil a batch, but perhaps a couple hours isn't really an issue.


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[nicklawmusic]

I'll go with the 180 I think. Do I just bring it to temp and then turn the heat off?

 

[geoffey]

I'll go with the 180 I think. Do I just bring it to temp and then turn the heat off?

Consider keeping it at 180 for 20 min. Or go to 185-190 and kill the heat, assuming it won't cool below 180 on its own for at least 20 min.


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[nicklawmusic]

And this will kill the bug?

 

[geoffey]

And this will kill the bug?

This process is basically pasturizing your wort, so yes.


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[nicklawmusic]

Thanks. Raised it to 87c and I now sitting with the lid on, covered under 3 coats. Really appreciate your help. Had no idea about the lacto bug!