Having a go at an overnight mash to save time

I've read up a while back at overnight mashing. With the second little addition to our family coming along any day now i figure it's the only way I can keep my taps flowing for the first 6+ months. It will allow me to split up my brew day into friday night/sat morning and hopefully I can finish before the kids are having lunch on sat.

I got a lot of info from the following articles/threads:

https://www.homebrewtalk.com/f36/overnight-mash-keeping-my-cool-295579/

https://byo.com/hops/item/931-is-th...mash-overnight-and-just-sparge-in-the-morning

http://www.fermentarium.com/homebrewing/brewing-beer/shorten-your-brew-day-with-overnight-mashing/

I'll be trying to technique out this weekend with a red IPA/Belgian IPA split batch. I'll post my recipe and experiences from this batch here along the way. If this works well i'll be using it almost exclusively for a while.

I can't speak to overnight mashing, I've had some success with mashing and sparging at night, then transferring to kettle and bringing it to a boil for a couple minutes, then covering the kettle overnight and coming back to do the regular boil the next day. The key is bringing it to a boil before going to bed, so any lacto or other bacteria will be killed (or at least most of them, anyway).

With the overnight mash, I would be concerned about holding the correct temperature. If you spend too much time in the 140's, you might end up with an overly fermentable wort. The other worry is obviously souring your mash, which can start to happen pretty quickly given the right conditions.

At any rate, best of luck to you, and I am interested to hear how this turns out!

You may ignore the 60% efficiency, which was entirely due to my crush. I got 80-some% attenuation, so that saved my abv (explained on page 7, link is in OP).

https://www.homebrewtalk.com/showthread.php?t=515150

But really, the biggest real time-saver for me has been a 30 min mash.

75% efficiency w/BIAB 30 min mash

https://www.homebrewtalk.com/showthread.php?t=519602

douglasbarbin said:

I can't speak to overnight mashing, I've had some success with mashing and sparging at night, then transferring to kettle and bringing it to a boil for a couple minutes, then covering the kettle overnight and coming back to do the regular boil the next day. The key is bringing it to a boil before going to bed, so any lacto or other bacteria will be killed (or at least most of them, anyway).

With the overnight mash, I would be concerned about holding the correct temperature. If you spend too much time in the 140's, you might end up with an overly fermentable wort. The other worry is obviously souring your mash, which can start to happen pretty quickly given the right conditions.

At any rate, best of luck to you, and I am interested to hear how this turns out!

Click to expand...

to counteract this effect one mashes in a few degrees hotter than your standard recipe. I was going to shoot for 152 with my normal recipe, so for the overnight i'm going to dough in at 156 target temp.

HausBrauerei_Harvey said:

to counteract this effect one mashes in a few degrees hotter than your standard recipe. I was going to shoot for 152 with my normal recipe, so for the overnight i'm going to dough in at 156 target temp.

Click to expand...

It seems to me that doing so would actually worsen the effect, since alpha amylase will be more active at first and create shorter chains for the beta amylase to work on. Beta amylase can only get within three glucose units of a branch joint, but alpha can get within one unit. So the alpha amylase is able to "clip" the chains very close to the joints, allowing beta amylase to better chew them up from end to end.

douglasbarbin said:

It seems to me that doing so would actually worsen the effect, since alpha amylase will be more active at first and create shorter chains for the beta amylase to work on. Beta amylase can only get within three glucose units of a branch joint, but alpha can get within one unit. So the alpha amylase is able to "clip" the chains very close to the joints, allowing beta amylase to better chew them up from end to end.

Click to expand...

Now that you mention it what you say seems logical, but reports of other brewers experience with this technique were that if you want more body, mash higher.

I think somewhere in that long HBT thread I posted above there was a reason for it which I understood and bought at the time. i dont have the grasp of organic compounds that you seem to but my understanding is beta amalyse is less fermentable longer chain molecules, the alpha is more fermentable shorter chain. Thus the idea behind the higher dough-in temp was that you do but i believe the jist was that the higher initial temp produced more complex, less fermentable sugars, but this is only for a small fraction of the time of the mash. As the mash cools that longer chain stuff is broken down but not 100%, thus you get a wort of similar fermentability to that of a much lower mash temp for a 1 hour mash.

Regardless, many folks reported the higher temp help improve body in an overnight mash.

I had great success this past weekend with this technique, and the time I saved on saturday was just awesome. I doughed in at 156 ~930pm on friday. I had a 50qt coleman extreme cooler which was maxed out with ~20 pounds of grain and 8 gallons of water. I put saran wrap around the lid and wrapped the cooler in an old sleeping bag. I left it in my garage at ~60F until 630am, and the temperature had only dropped to 148.

I was really surprised how well it help temp overnight. My OG was 1.060 and i'll report back on my FG when things are done. I used white labs 001 with a starter built up to ~300B cells from old slurry.

I kegged this batch last night and I was really happy with my attenuation values and the beer. My IPA hit 1.014 with WLP001, when I made it a year ago and mashed at 152 I finished at 1.016. So similar attenuation was achieved with the overnight mash with an initial mash in 4 degrees hotter than the standard recipe.

For busy brewers and those with kids like me where it's hard to get a large solid chunk of time, the overnight mash should be a tool in our toolbox we turn to often. I'll be using it often going forward.

Hope this helps someone looking for info on this technique.

Psylocide said:

You may ignore the 60% efficiency, which was entirely due to my crush. I got 80-some% attenuation, so that saved my abv (explained on page 7, link is in OP).

https://www.homebrewtalk.com/showthread.php?t=515150

But really, the biggest real time-saver for me has been a 30 min mash.

75% efficiency w/BIAB 30 min mash

https://www.homebrewtalk.com/showthread.php?t=519602

Click to expand...

I do mashes from 20 minutes to half a day with excellent results. In a 20-30 minute mash, I dough in with strike water at about 130, then fast heat to 145 where the mash "officially starts". I then heat at about half a degree per minute to 155 or so where the bulk of conversion happens. Needless to say I do a lot of stirring when doing this. Attenuation has proven to be about the same as an hour "normal" mash, and efficiency is very good. Saturation and gelatinization as you climb in to the conversion range seem to prepare the grain for rapid conversion.
My other common method to save time is to dough in at noon, and pull the bag and boil when I get home from work. I've never done an overnight mash, but personally with a well insulated condition, and mash temps what they are, I doubt that souring would be an issue....... That 150+ deg mash temp is going to kill the lacto and aceto critters, and damage everything else enough to not be an issue.

H.W.

Just an update for those that are interested in this technique: I've done overnight mashing for 4 batches now and love it. It shaves 2+ hours off my Saturday brew-day time and I've gotten great beers with the attenuation I want. I've found a mash-in of 2 degrees above my standard mash temp works well, and I only lose about 8 degrees in 10-12hrs overnight.

I cannot recommend this technique enough for those with young kids and who are strapped for a large chunk of weekend daylight time to brew. I will likely try a variant of this sometime soon as well, just get up early and mash in before the kids get up, let the tun sit all day, then start the boil after 7pm when the kiddos are in bed.

HausBrauerei_Harvey said:

Just an update for those that are interested in this technique: I've done overnight mashing for 4 batches now and love it. It shaves 2+ hours off my Saturday brew-day time and I've gotten great beers with the attenuation I want. I've found a mash-in of 2 degrees above my standard mash temp works well, and I only lose about 8 degrees in 10-12hrs overnight.

I cannot recommend this technique enough for those with young kids and who are strapped for a large chunk of weekend daylight time to brew. I will likely try a variant of this sometime soon as well, just get up early and mash in before the kids get up, let the tun sit all day, then start the boil after 7pm when the kiddos are in bed.

Click to expand...

The dire predictions of excessive attenuation and souring all proved to be non-issues obviously. It's worth noting that at mash temps as high as 155+, full conversion happens pretty rapidly..... depending on crush. I've mashed in as little as 10 minutes using a fine crush, and BIAB, and doughing in with hot tap water (130F at the tap), rapid heating to 145 (the bottom of the conversion range), then slow heating to 155. I count the time from 145 to 155 as the mash, and stir frequently. 20-30 minutes works better, and we have quite a few people doing 30 min mashes with excellent results.

No matter how many people do overnight mashes, or 30 minute mashes, the nay sayers will always claim that it can't work, or that it will result in inferior beer.

H.W.

My readings have taugfht me that most conversion happens in the first 15 minutes. We mash for an hour "just to be sure". If you're trying to shorten up yoiur brew day, I'd suggest you concentrate on setting up all yiour euquipment the night begore ready to go in the AM (water in the kettle, grains laid out on the counter, hops additions weighed out and in zlock bags, sanitizer mixed up and on the floor, all utensels required in the sanitizer, ETC) If you brew like me you'll find it takes a supprising amount of time between "I'm going to brew this morning" and firing the strike water. I would be concerned with overnight mash promoting an infection. Its easier to prevent one than cure it after the fact.

Owly055 said:

No matter how many people do overnight mashes, or 30 minute mashes, the nay sayers will always claim that it can't work, or that it will result in inferior beer.

Click to expand...

But it takes all the fun out of my RIMS tube!

william_shakes_beer said:

My readings have taugfht me that most conversion happens in the first 15 minutes. We mash for an hour "just to be sure". If you're trying to shorten up yoiur brew day, I'd suggest you concentrate on setting up all yiour euquipment the night begore ready to go in the AM (water in the kettle, grains laid out on the counter, hops additions weighed out and in zlock bags, sanitizer mixed up and on the floor, all utensels required in the sanitizer, ETC) If you brew like me you'll find it takes a supprising amount of time between "I'm going to brew this morning" and firing the strike water. I would be concerned with overnight mash promoting an infection. Its easier to prevent one than cure it after the fact.

Click to expand...

Yeah that's a good point, and I was already doing most of this and was looking for more time savings. All the reading I did said as long as the mash stayed above 140 I should be fine, and that's what I've done with not a sourish note anywhere in my beers.

To all those worrying about an infection: sometimes that's exactly what you want.

I don't normally mash overnight for clean beers, (except saisons) but it's my go-to method for no-boil, no sparge sours. Dough in at like 153, let sit overnight, and drain to fermenter the next morning. Let ride down to pitching temp for brett or wlp644, pitch the yeast, and you've got yourself a gose-like thing in a week and a half. It pretty much requires kegging, because the rich menagerie of microbes on the grain and the wild yeast you pitch will chew on complex carbohydrates forever. You can control the level of sour by pitching more lacto than was on the grain naturally or waiting to pitch yeast. Marshmallow pellicles will form.

Overnight mashes are a useful tool for me when I'm making saisons or fast sours, but if you are trying to make something that tastes some exact specific way that you want to replicate every time, they aren't the best.

I'm drinking a brown now that was mashed overnight. It's a great summer beer, very light body, high attenuation, clean and crisp. No souring at all, but I would bet it did finish quite a bit lower than if I had mashed for 60 minutes (even though I mashed in at 158, this was in the mid 130s the next morning). It's great for this beer; might not make sense for some styles, though.

I've been wanting to build a simple system that will begin my mash long before I get up in the morning... or while I'm at work, so that except for crushing the grain and putting it in the system, and doing my settings, the only thing I have to do is the boil.

I've thought a great deal about how to go about this, and it probably will consist of a home built pump of very simple design which will be right in the single brew kettle, with the drive motor up above, and a grain tube with upper and lower screens mounted above the brew kettle, an electric element one or more timers, two temperature controls and a few relays. The drive motor for the pump can be as simple as the power head for a cheap electric mixer. Centrifugal pumps are incredibly simple.... I'll built my own with some odds and ends of stainless steel...... I've built pumps and blowers before and it isn't difficult....if you have a few shop tools.

The grain tube will be mounted above the brew kettle and off to one side and will have upper and lower screens. A hose will carry the water / wort up to the bottom of the grain tube and another will return it. Because the grain tube is elevated, it will drain when the pump is shut off. The kettle will NOT have a tap or valve.

The grain tube and kettle will be filled the night before, and a timer will start the process at the proper time.

Step 1: Heat to strike temp........ controlled by STC 1000
Step 2: Temp sensor (STC 1000) trips a relay(s) which take it out of the circuit and put a
PID controller in charge of temp control which is preset for mash temp, and
starts the pump, and a mash timer
Step 4: Mash timer stops the process and allows the mash tube to drain back to the brew
kettle.


None of this is "rocket science".......... It doesn't require micro processors...... and I'm "microprocessor hostile".......... Don't ask me why... I just have a mental block I guess. I'd rather just set a mechanical timer and dial in a couple of temp controllers. I've done "hard wired logic" all my life using cheap relays, as well as mosfets and a few cheap ICs. I'm simply not interested in programming a microprocessor.

The system could be enhanced in a couple of ways........ It could run a wake up alarm. You could even go to a microprocessor system, and go to "boil mode" using "hop droppers", so the boil was managed also. Sensing the boil is a matter of temperature rise rate.... When the temp stops rising, you are boiling..... temp is not accurate due to altitude, but rise rate is. One minute with no increase in temp, and your 60 minute addition is "dropped".......from there it's a countdown. The submerged pump would have no real temp issues....no seals to worry about, etc, and so could be used during the boil, which means that you could circulate through hop chambers instead of dropping the hops into the boil..... a simple matter of valving. You could go a step or two further..... running through your counterflow chiller (I won't ever own a plate chiller).... and even pitching yeast.

I personally don't see myself ever going beyond just starting the mash at night so I can do the boil the next morning........The day I can't commit an hour and a half to boiling and chilling beer....... I'll quit brewing!! The point is that the limit is your imagination and of course how lazy you are.


H.W.