• Please visit and share your knowledge at our sister communities:
  • If you have not, please join our official Homebrewing Facebook Group!

    Homebrewing Facebook Group

Mash night before, boil in morning

Homebrew Talk

Help Support Homebrew Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

ILMSTMF

Supporting Member
HBT Supporter
Joined
Jan 17, 2014
Messages
571
Reaction score
175
Hello,

BIAB, 5 gallon batch, 15 gallon kettle. In an effort to save time on brew day, I am considering doing the hour mash the night before. Not intending to leave the grains mashing overnight, please read on.

Here is my idea for method. Please let me know which steps should be changed to make this successful:

• In driveway, heat strike water 10F above target mash temp
• dough in
• get help to move kettle from driveway to garage where 1) it is warmer and 2) I have the hoist to do the bag lift
• wrap kettle in old blanket, rest for an hour
• lift the bag, let it drain for 10 minutes
• move the kettle BACK out to the driveway, heat the wort to 165F. Kill burner. Or should I bring all the way to a boil?
• move kettle back into garage.
• At this point, there's no "10 minute mash out". The wort has been brought to mash out temperature and now it is going to sit over night.
• Wrap kettle in old blanket, let it sit over night.
• Within 12 hours, get the boil going. Proceed as normal.

The goal here is not to actually MASH overnight but to get the mash portion of brew day done in advance to save time on brew day. Like the days when I was extract brewing, just start with the boil! haha

I can incorporate a dunk sparge into this process but not sure when to do so (night before or morning of boil?) Or if it's even worth it.

So, what holes do I have in my plan? Thanks!
 
What's the purpose of wrapping the kettle in the blanket?

Is mashing in your open ventilated (fan, etc.) garage not an option to avoid moving the full kettle? Get a CO monitor if you think that might be an issue.
 
Wrapping the kettle to maintain the heat of the contents within. Doing this, even on a typical brew day, I'm still regularly losing ~10 degrees over the hour mash.
Would this step be more appropriate if, for example, the grains were still soaking over night? In my case, would it be safe to let the temp of the wort (without grains in it) drop significantly in those overnight hours?

Been down this road already with garage brewing - the family and I just don't want to risk any problems. Yes, moving a heavy, hot kettle around is dangerous. In my opinion, I find that less stressful than mashing and/or boiling in garage.
 
Wrapping the kettle to maintain the heat of the contents within. Doing this, even on a typical brew day, I'm still regularly losing ~10 degrees over the hour mash.
Would this step be more appropriate if, for example, the grains were still soaking over night? In my case, would it be safe to let the temp of the wort (without grains in it) drop significantly in those overnight hours?

Been down this road already with garage brewing - the family and I just don't want to risk any problems. Yes, moving a heavy, hot kettle around is dangerous. In my opinion, I find that less stressful than mashing and/or boiling in garage.
My bad, I should have been more specific. What is the purpose of wrapping the kettle with a blanket after mashout? I understand why you insulate during the mash.

I completely understand about being hesitant to brew in your garage. I have done it and I know members of my club do it but you definitely should be careful. If you aren't trying to move the hot kettle yourself you are probably better off doing what you're doing.
 
My bad, I should have been more specific. What is the purpose of wrapping the kettle with a blanket after mashout? I understand why you insulate during the mash.

I completely understand about being hesitant to brew in your garage. I have done it and I know members of my club do it but you definitely should be careful. If you aren't trying to move the hot kettle yourself you are probably better off doing what you're doing.

All good!

The only time I move the kettle WITHOUT a partner is when it is filled with cold tap water and on its way to the burner for strike heating. Every other kettle move after that point is done with a partner to team lift.

So, method look good? Literally plan is to do this tonight if I can get some confidence from my friends here. If not, will just do a full mash-to-pitch brew day as usual. Would really like to have that free time back to myself tomorrow though...
 
The only thing I would change is the temp you heat it to after draining. You'll will still have alpha amylase activity at 165F. Anytime I want to kill enzymatic activity if wort is going to sit for a bit, I raise it to 185F.


Technically, it'd probably be good to pre-acidify to 4.5 pH to prevent any enteric bacteria. However, I doubt you have a pH meter and such, so I totally wouldn't worry about that (disclaimer that I absolve myself from any harm done due to bacterial infection). Seriously though, pH shouldn't be an issue.
 
I did pick-up some tips from Matt B. at Firestone Walker.....they adjust mash pH to 5.4, wort pH to 5.2, and make sure finished beer pH is 4.5 or less.
 
The only thing I would change is the temp you heat it to after draining. You'll will still have alpha amylase activity at 165F. Anytime I want to kill enzymatic activity if wort is going to sit for a bit, I raise it to 185F.


Technically, it'd probably be good to pre-acidify to 4.5 pH to prevent any enteric bacteria. However, I doubt you have a pH meter and such, so I totally wouldn't worry about that (disclaimer that I absolve myself from any harm done due to bacterial infection). Seriously though, pH shouldn't be an issue.

I did pick-up some tips from Matt B. at Firestone Walker.....they adjust mash pH to 5.4, wort pH to 5.2, and make sure finished beer pH is 4.5 or less.

So, what do you folks think?

A) Lift bag, drain, adjust pH to X value, heat to 185F, wrap up kettle, boil within 12 hours?

B) Lift bag, drain, adjust pH to X value, DON'T HEAT ANY FURTHER, wrap up kettle, boil within 12 hours?

C) Lift bag, drain, wrap up kettle, boil within 12 hours?

If A or B, what pH value? I do have a cheap pH meter and phosphoric acid on hand.
Considering making this a reality - finding 6 hours to carve out in a single day proving to be difficult. Thanks!
 
Wait, you are wanting to save time on your brew day by turning your single brew day into two brew days?

I BIAB also and my sessions, including cleanup usually take about 4-5 hours.
 
Yes. I've had a 4.5 hour brew day. Typically, distractions and my own neurosis turn the whole day into ~6 hours.
 
I don't know how much trouble bugs can be in 12 hours when the wart is going to boil the next day. I would say option C should be good to go. The wart is basically pasteurized after a hour at 150+, cover, wrap and boil in the a.m. This makes sense to me, but I'm no microbiologist either. Cheers :mug:
 
I don't know how much trouble bugs can be in 12 hours when the wart is going to boil the next day. I would say option C should be good to go. The wart is basically pasteurized after a hour at 150+, cover, wrap and boil in the a.m. This makes sense to me, but I'm no microbiologist either. Cheers :mug:

Wort is pasteurized in about 30 mins at 140, or 5 seconds at 160 F.

I think you need to get temp over 170 to denature the enzymes.
 
Option D: Lift bag and let drain, cover the kettle, boil within a day or 2. The wort will be pasteurized and with the lid on there will be little getting in. Any micro organisms that do won't have much time to multiply and they will all die with the boil.

Option E: Lift bag and start heating the wort while the bag drains, add hops and boil for 30 minute, cover and let cool overnight. This only works if you have only bittering hops as any late additions hops will become bittering hops instead of flavor or aroma hops.
 
I don't BIAB so can't speak to that but I mash one day (usually in the evening) and boil the next day quite often. It works very well for me and I always heat the wort with a cover on the kettle to at least 185 before shutting everything down. The next morning I remove the kettle lid and proceed with the boil.
Just to be clear, the lid is only used to keep possible contaminants out and is not used during the actual boil.
 
To keep it super simple you could mash, leave overnight with grains in, pull bag in morning or whenever, start boil, then put lid on after boil and allow to cool slowly until pitch temp reached, put in fermenter and pitch yeast. Talk about simple - Overnight mash and no chill!
 
Wort is pasteurized in about 30 mins at 140, or 5 seconds at 160 F.

I think you need to get temp over 170 to denature the enzymes.

Great.

Option D: Lift bag and let drain, cover the kettle, boil within a day or 2. The wort will be pasteurized and with the lid on there will be little getting in. Any micro organisms that do won't have much time to multiply and they will all die with the boil.

I don't BIAB so can't speak to that but I mash one day (usually in the evening) and boil the next day quite often. It works very well for me and I always heat the wort with a cover on the kettle to at least 185 before shutting everything down. The next morning I remove the kettle lid and proceed with the boil.
Just to be clear, the lid is only used to keep possible contaminants out and is not used during the actual boil.

I'm thinking I'll be going with Option D suggested by RM-MN. However, what about the points folks here have made about pH? Must I consider that?

Here's a summary of my plan. Feel free to modify/correct, thank you.

• Strike to ~160
• Mash at about ~150 for one hour
• Lift bag, drain for 10, squeeze
• Heat to 180F (note - I can't drain and heat simultaneously due to bag hoist point/burner height.)
• pH adjustment?
• cover kettle, wrap in blanket
• boil within 12 hours

Thank you, friends.
 
Great.





I'm thinking I'll be going with Option D suggested by RM-MN. However, what about the points folks here have made about pH? Must I consider that?

Here's a summary of my plan. Feel free to modify/correct, thank you.

• Strike to ~160
• Mash at about ~150 for one hour
• Lift bag, drain for 10, squeeze
• Heat to 180F (note - I can't drain and heat simultaneously due to bag hoist point/burner height.)
• pH adjustment?
• cover kettle, wrap in blanket
• boil within 12 hours

Thank you, friends.

Mash until conversion is done. It may take 20 minutes, it may take 120 minutes, all depending on the milling of the grain and what size of particles that milling left you with. The typical mash takes less than 60 minutes to complete but yours certainly could be atypical.
Lift bag and let drain for a couple minutes, then squeeze. A pair of long rubber gloves will help you avoid burned hands.
There is no real need to heat to 180. Any unconverted starches will be in the grains and when you remove them from the mash tun you have "mashed out". Well, when you finish squeezing the wort out of the bag and discard the grains you definitely have mash out. At 150 for an hour your wort is pasteurized.
I don't see much need for a pH adjustment. The wort is pasteurized, bacteria will be inhibited by the lid, and it takes time for the bacteria to multiply. You won't give them much time and then you will boil the wort to kill any that got established. Covering the kettle will keep most bacteria out.
Wrapping in a blanket is only necessary if you are cold. I'd suggest you go into the house to warm up instead of wrapping in the blanket....unless you have a wife to wrap into the blanket with you.:D
Boil soon. Soon is a loose word. It could be 12 hours in this case or maybe even 24. I probably wouldn't let it go much longer than that.
 
Mash until conversion is done. It may take 20 minutes, it may take 120 minutes, all depending on the milling of the grain and what size of particles that milling left you with. The typical mash takes less than 60 minutes to complete but yours certainly could be atypical.
Lift bag and let drain for a couple minutes, then squeeze.

Here's where the dumb comes out - How do I know when it's done? Gravity test? I wouldn't know what a target mash gravity would be specific to a recipe; guess I better find a calculator.


There is no real need to heat to 180. Any unconverted starches will be in the grains and when you remove them from the mash tun you have "mashed out". Well, when you finish squeezing the wort out of the bag and discard the grains you definitely have mash out. At 150 for an hour your wort is pasteurized.
I don't see much need for a pH adjustment. The wort is pasteurized, bacteria will be inhibited by the lid

Excellent. So no extra heating. That's fine with me, it'll save me the trouble of taking the kettle out of garage and into driveway to restart the burner. Man, this could be great! Would only have to move the full kettle once for the evening (warm water off of burner into garage for dough in/mash/hoist).
OK, no wrap, no problem. Was worried losing heat over that time would affect the wort negatively. Hmmmm, sharing the blanket...
https://cdn.shopify.com/s/files/1/1155/4228/files/518ce986acb68_large.jpg?2484269677853233327
 
You can use Iodine to test if there are unconverted starches, but it you mash for 60, 99% of beers will be done converting and if not RM is right, the unconverted starch is in the grain, not the wort.
 
Now that its cold out at night I'm thinking of doing a Raw ale, mash at night, run off to the kettle, set outside on the back porch with the lid on to chill and dump in the fermenter and pitch yeast in the morning.
 
Now that its cold out at night I'm thinking of doing a Raw ale, mash at night, run off to the kettle, set outside on the back porch with the lid on to chill and dump in the fermenter and pitch yeast in the morning.

If I were to set a kettle of wort out tonight it would be a solid mass by morning. You must have a different definition of cold than I do. The temperature is currently 15F and is likely to go down.
 
Yeah, its like 30F at night, it doesn't get really cold until Jan/Feb, but some years are colder than others. This year, we still have some varieties of pears on the trees and about 50% of the leaves on the maples, which is unusual for the first week of Novemeber.
 
Here's where the dumb comes out - How do I know when it's done? Gravity test? I wouldn't know what a target mash gravity would be specific to a recipe; guess I better find a calculator.


That's the problem, there isn't a real quick way to tell....except iodine. A bit of the grain and a drop or 2 of iodine on it and if it is done converting, there will be no change in the color but starch turns the iodine to a dark purple/blue color. As mentioned by cmac62, usually conversion is done in 60 minutes so you can just go by that. If you own a refractometer you can take a quick sample, wait a few minutes and take a second sample and compare the readings. If you do this, stir the mash well before each sample.

Excellent. So no extra heating. That's fine with me, it'll save me the trouble of taking the kettle out of garage and into driveway to restart the burner. Man, this could be great! Would only have to move the full kettle once for the evening (warm water off of burner into garage for dough in/mash/hoist).
OK, no wrap, no problem. Was worried losing heat over that time would affect the wort negatively. Hmmmm, sharing the blanket...
https://cdn.shopify.com/s/files/1/1155/4228/files/518ce986acb68_large.jpg?2484269677853233327

That's the problem, there isn't a real quick way to tell....except iodine. A bit of the grain and a drop or 2 of iodine on it and if it is done converting, there will be no change in the color but starch turns the iodine to a dark purple/blue color. As mentioned by cmac62, usually conversion is done in 60 minutes so you can just go by that. If you own a refractometer you can take a quick sample, wait a few minutes and take a second sample and compare the readings. If you do this, stir the mash well before each sample.
 
Excellent. I will purchase some iodine.

Yes, I have a refractometer and will also use for this.

Thank you all!
 
I think that in terms of shortening the total time you spend brewing, the overnight mash is better than trying to complete a standard mash on day and boil the next. With the overnight mash you get to walk away for the day immediately after doughing in and insulating your kettle. That mash time is truly time you can deduct from your brewing time because you are not required to wait a certain period that day and then do something else to it.

I’m not saying your plan won’t work. I just don’t think it’s the most efficient use of your time.
 
With the overnight mash you get to walk away for the day immediately after doughing in and insulating your kettle. That mash time is truly time you can deduct from your brewing time because you are not required to wait a certain period that day and then do something else to it.

For clarification, I don't intend to actually mash over night. Since this is BIAB, my intent is to complete the mash in evening, lift bag and drain, cover kettle, and boil next morning. FWIW, I'd still prob walk away after dough in then return an hour later to check then finish. :rockin:
 
Excellent. I will purchase some iodine.

Yes, I have a refractometer and will also use for this.

Thank you all!

If you use the iodine it may show that conversion is complete in less than 20 minutes. Do not shorten your mash that much. It takes more time than that to extract the flavors from the grains and making a very short mash will get you beer but it won't have much flavor. I don't recommend less than a 30 minute mash for that reason.
 
QUOTE

"The only time I move the kettle WITHOUT a partner is when it is filled with cold tap water and on its way to the burner for strike heating. Every other kettle move after that point is done with a partner to team lift."

A thought... I'm handicapped (one arm) and can't lift a kettle of water at all so before I went electric BIAB I had built a platform to mount my burner and pump on with nice sized wheels under it. Roll it out to the driveway, dump the water in - at that time malt extract brewing - do my boil, turn off the burner and roll it back into the garage - being careful not to slosh- cool and pump into my fermenter. No lifting at all hot or cold.

If you are going to move in and out of your garage this might work when you don't have help.

Cheers! Don
 
Back
Top