# What are your ways to split up your brew day/s?



## Qualia (18/8/17)

I'm now past a dozen brews and have noticed that my brew days normally take 5 hours (AG) which conclude with me hosing off my gear at 1am much to my neighbours' delight. 

I'm thinking about splitting up my brewing over a few nights to make life (and that of the wife's) easier:

Day 0: Buy ingredients in bulk (done)
Day 1: Crack grain / make starter
Day 2: Mash grain then pump into my HLT/BK
Day 3: Boil, chill and pitch. 

Does this sound feasible? 

What do you do?

Cheers!


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## Danscraftbeer (18/8/17)

Note your Wort can start souring leaving for even just one day before boiling. Known as Kettle Souring technique to make tart sour beer.
Cubing, (no chill) is great for breaking up the brew process and cuts out chilling procedure and time. Allows you to brew the beer any time like brew on a rainy day and store it ready to ferment when ever you want, or can get around to it.
I will mill the grains and keep in a sealed pail bucket, not for too long though. Day before, a few days is fine. I have got the mash in the esky and left overnight to sparge, boil next morning that works ok too.


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## Mardoo (19/8/17)

Easiest way, buy a Braumeister or Grainfather. Set and forget, 'til runoff.

I haven't done so myself, but there are a number of folks on here who have used a 3V system with a slow-ramping HEX, starting it up at bedtime, and working out the timing so mashout comes around morning, with an STC1000 holding the temp at mashout until you're ready to sparge. I've also read of folks using an outlet timer, doughing in cold and setting the timer to start the mash and pump sometime before wakeup.


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## bradsbrew (19/8/17)

1. Day before - set up rig, fill hlt, millgrain. Put hlt on timer so it is at mash in temp when you get home.
2. Brewday- brew batch and no chill.
3. Day after- clean up


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## Andy_27 (19/8/17)

Day before, I fill urn with water and set timer for about 6am. Get out grains and water additions ready.

Brew day, I wake up, adjust strike water temp. Add water additions, Mill grains and mash in. Have brekky and get the kids sorted while its mashing. The normal brew day follows and Im usually done and cleaned up just after lunch time.


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## barls (19/8/17)

bradsbrew said:


> 1. Day before - set up rig, fill hlt, millgrain. Put hlt on timer so it is at mash in temp when you get home.
> 2. Brewday- brew batch and no chill.
> 3. Day after- clean up


this is what i do as well.


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## Black Devil Dog (19/8/17)

I'd much rather condense my brewing, than spread it out over more days

I brew 2 double batches on the same weekend.
That's 96 litres in 2 days.
My brew days generally take about 8 hours. That's with everything cubed and cleaned.
Try to start as early as possible, 7.00 - 8.00am.
The only downside is that there are too many weekends when I'm not brewing.
I've wasted a lot of time in the past trying to decide what to brew on a brew day morning, so a big time saver for me is to have my recipes finalised before brew day.


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## cliffo (19/8/17)

I do double brew days pretty much as a matter of course.

Set the timer on the Robobrew the night before and _*aim *_to get up around 5am, mash in and go back to bed for a bit before getting back up for the mash out and rest of the brew day.

Here we are at 10am and I'm half way through the mash on my 2nd brew for the day.

I'm generally all done and cleaned up by 1pm depending on what I'm brewing (lagers tend to stretch the brew session out a bit longer).


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## Dan Pratt (19/8/17)

Thursday finalise beer recipe and water designs. 30mins

Friday evening, mill grains, add salts to milled grain and mash in around 9pm. 30mins

Overnight mash on Braumeister with extended mash out for 6hrs. 

Wake up Saturday morning 7am, sparge, boil, whirlpool and into No-Chill cube and clean up by 930am. 

Pretty much about 3 1/2 hrs of my time for a no chill not including the overnight mash time cos I'm sleeping. 

When I make a hoppy beer IPAs then I chill with CFC, that will add another hour or so and those beers are usually a 90min boil. 

Investing into an BM lead to massing time savings through overnight mash.


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## Judanero (19/8/17)

Mill the day before, if brewing on the weekend heat your water about ten degrees over mash in temp the night before (right before bed) and then insulate your pot (wrap in sleeping bag etc).
Wake up EARLY and you should be fairly close to mash in temp, get all your hops, spare water etc ready during mash.
Boil, no chill.

When I brew on a school night I duck home at lunch and bring my water a bit above mash temp, insulate, ready to mash in straight after work.

I guess you could do a short (15 mins or so) boil after mash out, cover the kettle and then actually do the boil the next day if you wanted to split over two days.


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## manticle (19/8/17)

Start earlier.
Crack grain day before.
Clean day after
No chill.

Brewday for me is a relaxing day for myself - no kids and my partner works both days, so after a 5-6 day working week, I'm super happy to spend the whole day brewing, gardening, listening to music, hanging with cats, watching futsal, doing household chores/maintenance and generally having me time. Just need to start drawing again.


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## Adr_0 (19/8/17)

Not sure what kind of control you have available but you could easily fill up HLT, dechlorinate and set to maintain strike temperature and also crack grain into a bucket w/ lid the day/night before.

And yeah as others have suggested, you can always get a bit of programming into your system, so on day two you strike, hydrate, go through protein/whatever then your conversion rest(s) for a couple of hours then have it sitting on mash out temperature, with your HLT ready to sparge first thing in the morning and come up to boil.


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## good4whatAlesU (19/8/17)

I'm a bit time poor at the moment too - so thinking about this.

The mash I find quite easy and it's possible to just 'set and forget' for an hour. The boil is the time consuming bit (requires constant supervision).

I'm thinking of ways to speed and get the boil done in 10 minutes. Maybe a few large kitchen jugs - just boil the crappers out of it for 10 minutes and straight into a cube...


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## manticle (19/8/17)

Not sure I understand GFWAY.

How are you boiling? Vessel, volume?

Sounds like you're going to do several small 10 min boils (which will take how much total?). I know some people do short boils but I think it's a bad idea.


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## malt junkie (19/8/17)

Enslave your children, my youngest is the mill motor from hell, my eldest isn't bad with lifting and cleaning though he's better at drinking so, I don't know that I'm ahead. And both need supervising with their brew jobs, though that gives me time to sample a few myself. Swings and round-abouts brew day is brew day; preparation is key, and no chill is a gift from the gods.


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## mofox1 (19/8/17)

If you use a herms.. mash in cold the night before, preheat HLT according to where you live in this fine country. Melbourne, might as well get it up to 100 at this time of year, just crack the ice in the morning. QLD'ers might as well use the cold (lol) tap.

Mashing in cold is a godsend - I've found I don't need to throttle the recirc when I turn it on in the morning, unlike mashing in at/near sacc temp. Just flick the switch on and go back to bed. Better yet, use a timer.


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## good4whatAlesU (19/8/17)

manticle said:


> Not sure I understand GFWAY.
> 
> How are you boiling? Vessel, volume?
> 
> Sounds like you're going to do several small 10 min boils (which will take how much total?). I know some people do short boils but I think it's a bad idea.


Yes not sure myself manticle, just cogitating on it.
The boil is the worst part of brew day, 90 minutes minimum of almost constant supervision - I don't have the time..

edit: Approx 13L boil.


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## manticle (19/8/17)

Why constant? Boil is the bit I mostly walk away from.


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## malt junkie (19/8/17)

manticle said:


> Why constant? Boil is the bit I mostly walk away from.


He needs a bigger pot, bloody tempted to send him a spare. (cause I love the bloke's banter) Hell steal a keg FFS! No thats bad PM me We'll do a deal.
(100L CB Pot BNIB)
ED: or 30L crown Urn (you can get 22l to the boil) 15L easy!

MJ


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## good4whatAlesU (20/8/17)

manticle said:


> Why constant? Boil is the bit I mostly walk away from.



Adjusting heat and watching for boil-overs, adding hops etc. Can't leave the room really...

I run 9.5L kegs so boil about 13L (lose 3.5L or so before it reaches the kg).


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## Grott (20/8/17)

bradsbrew said:


> 1. Day before - set up rig, fill hlt, millgrain. Put hlt on timer so it is at mash in temp when you get home.
> 2. Brewday- brew batch and no chill.
> 3. Day after- clean up



Out of interest, how much time do you spend on 1. 2. and 3.? Is this for 23 litres?
Thanks


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## bradsbrew (20/8/17)

Grott said:


> Out of interest, how much time do you spend on 1. 2. and 3.? Is this for 23 litres?
> Thanks


That was advice on how to split a brewday when brewing at night after work. when i had single batch systems i did this a few times, can't remember the times breakdown.
With my current 3v herms i punch out between 100 and 140L a batch. I start by filling the HLT around 6am of a Saturday or Sunday. I am done by 2pm with full cubes and cleaned the brew rig. I also mow and do other stuff during the day. Because i have 5-7 cubes each batch, i dont have brew as often.
I pithed 2 cubes yesterday, so i am down to 7 full 25L cubes. I am now at the stage where i brew for the fun of it, not because i need to fill a cube.


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## manticle (20/8/17)

good4whatAlesU said:


> Adjusting heat and watching for boil-overs, adding hops etc. Can't leave the room really...
> 
> I run 9.5L kegs so boil about 13L (lose 3.5L or so before it reaches the kg).




Get a bigger pot.


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## good4whatAlesU (20/8/17)

I have a 20L pot, so boiling 13litres is not a problem.

It still takes 90 minutes.


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## wynnum1 (20/8/17)

I would rather start at at 1 in the morning then finish at that time .


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## Camo6 (20/8/17)

good4whatAlesU said:


> I have a 20L pot, so boiling 13litres is not a problem.
> 
> It still takes 90 minutes.



I'm guessing you brew in the kitchen? This would explain the need for vigilance. Hell hath no fury like a Smeg covered in sticky wort.


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## Grott (20/8/17)

bradsbrew said:


> That was advice on how to split a brewday when brewing at night after work. when i had single batch systems i did this a few times, can't remember the times breakdown.
> With my current 3v herms i punch out between 100 and 140L a batch. I start by filling the HLT around 6am of a Saturday or Sunday. I am done by 2pm with full cubes and cleaned the brew rig. I also mow and do other stuff during the day. Because i have 5-7 cubes each batch, i dont have brew as often.
> I pithed 2 cubes yesterday, so i am down to 7 full 25L cubes. I am now at the stage where i brew for the fun of it, not because i need to fill a cube.View attachment 107772



Seems simple enough and works well for you.
Isn't it great when your ahead and you are not committed to "have to brew". I have 66 litres kegged, chilled, carbed and ready to drink brews and 89 litres of kegged, ready to be chilled and carbed. ( is this being a pig? If it is then good)


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## Tony121 (20/8/17)

good4whatAlesU said:


> I have a 20L pot, so boiling 13litres is not a problem.
> 
> It still takes 90 minutes.



I think the point is that you shouldn't need to stand over it for those 90 minutes. Once the boil has broken through there is little risk of boil over. You can walk away and return when you need to add hops, finings, etc.


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## good4whatAlesU (20/8/17)

I don't stand over it as such, but leaving an open vessel boiling for 90 minutes without supervision with other people in the house is not safe in my opinion.

Going to the shed for several hours is simply not possible in current circumstance.


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## Black Devil Dog (20/8/17)

bradsbrew said:


> That was advice on how to split a brewday when brewing at night after work. when i had single batch systems i did this a few times, can't remember the times breakdown.
> With my current 3v herms i punch out between 100 and 140L a batch. I start by filling the HLT around 6am of a Saturday or Sunday. I am done by 2pm with full cubes and cleaned the brew rig. I also mow and do other stuff during the day. Because i have 5-7 cubes each batch, i dont have brew as often.
> I pithed 2 cubes yesterday, so i am down to 7 full 25L cubes. I am now at the stage where i brew for the fun of it, not because i need to fill a cube.View attachment 107772



Do you end up with 100 - 140 litres of pretty much the same brew, with the exception of cube hops and dry hops?


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## bradsbrew (20/8/17)

Black Devil Dog said:


> Do you end up with 100 - 140 litres of pretty much the same brew, with the exception of cube hops and dry hops?


Yes. Although with diferent yeasts , dry hop etc, i can end up with several different beers. There is also the option of steeping specialty malts(and boiling off) to add to the fermenter when pitching a cube. For example , steeping some crystal and raost barley to turn an english bitter cube into a dark ale or stout.


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## manticle (20/8/17)

good4whatAlesU said:


> I don't stand over it as such, but leaving an open vessel boiling for 90 minutes without supervision with other people in the house is not safe in my opinion.
> 
> Going to the shed for several hours is simply not possible in current circumstance.


Your house, your rules but something is off if you need to watch a 20 L boiling pot for 90 mins and doing multiple 10 min boils is not a good solution (also sounds messy and just as hands on and time consuming as your 90).


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## good4whatAlesU (20/8/17)

manticle I stated already that I don't hover over it, it's just one part of my brewday - given current circumstance I'd like to improve.
Either contribute something useful to the thread or bugger off.


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## manticle (20/8/17)

The useful bit I was trying to get across to you was that 10 min boils are a really bad idea, despite what you may read elsewhere. I'm not familiar with the limitations of your equipment or household so can only make suggestions based on the info you make available. 

Keep your aggro chips off your shoulder, chief. I was not having a go and have no need nor desire to.


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## good4whatAlesU (20/8/17)

no chief, just a lowly Indian.

Why didn't you just communicate your reasoning? Or ask what gear I had before the critique? It just comes across very patronising.


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## manticle (20/8/17)

Why don't you give a bit more information about your setup and process?

Not intending to be patronising - just couldn't work out your methods or reasoning and you've been more defensive than you have been forthcoming.

I'd be surprised if patronising is how I'm generally viewed but I've been wrong before.


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## good4whatAlesU (20/8/17)

You may not intend to be, but you often are.

My set-up (thanks for asking) is simple - an insulated mash vessel (10L SS double wall with a bazooka tube) from which the wort (13L or so) is transferred by gravity to a boil pot (20L). From there to a fermenter

I make small batches to suit 9.5L kegs.


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## manticle (20/8/17)

I blame my mum.

Doing a 90 min boil is a great idea (my default is 90). Don't mess with with that bit - find a different shortcut.


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## Tony121 (20/8/17)

good4whatAlesU said:


> I don't stand over it as such, but leaving an open vessel boiling for 90 minutes without supervision with other people in the house is not safe in my opinion.
> 
> Going to the shed for several hours is simply not possible in current circumstance.



Completely understand. At the end of the day we all need to invest time for this hobby. There will be areas that can be made more efficient, though taking short cuts has its consequences. 

As Manticle mentioned, reducing the boil time is not a good idea.


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## razz (20/8/17)

Semi-automation is great. Set up equipment and dough in before bed and then out of bed at 6 or 7 and lift the mash and proceed with boil. A couple of hours brewing while I'm sleeping.


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## good4whatAlesU (20/8/17)

Okay... But is boil time the same for all volumes or can it be adjusted according to surface area/ intensity?

I.e. Do you need to boil 2 litres of wort for 90 minutes?


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## Jack of all biers (21/8/17)

Same for volume, not necessarily intensity. The obvious reasons for boiling for a time period are IBU extraction/conversion, but there are far more important reasons, which effect the stability of the resultant beer. I obtained a useful sheet on the reasons for the boil (on my phone so can post later this evening if MHB doesn't beat me to it). 

90 mins is not mandated and 60 min boils are quite common. I think you could get away with an intense 45 min boil, especially if the beer is consumed fairly quickly, but short cuts have consequences.


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## good4whatAlesU (21/8/17)

Would be interesting to get lab results for parameters (e.g DMS) and graph them against length of boil for different volumes.
I suspect running 4x 3L intense boils (12L total) would be quicker than doing my current 12-13L 90min boil.

edit: I can run 4 x 3L boils simultaneously (the boil off volume after 10min would be similar to 12L 90 min boil).

Hop additions could be added separately (e.g. dry hop in fermenter) or a small liquid addition.


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## Jack of all biers (21/8/17)

Here you go. I've thrown in a couple on Beer stabilisation also.


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## good4whatAlesU (21/8/17)

Thanks, very interesting read. I shall ponder over it.

It would be nice to see some data (appears missing in above literature) on boil volumes and surface area on chemistry and speed/change of volatiles.

Another technique is potentially not boiling at all, thereby reducing likelihood of precursor molecule to DMS at all. Open fermentation seems also to reduce DMS compared to a conical a few ways to skin the cat it seems.


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## manticle (21/8/17)

If smm is not transformed and evaporated during the boil, it can be transformed during fermentation and the resulting dms will remain in the beer.

Many, many other good reasons for boiling - colour and flavour development are the two high on my list but wort sterilisation and hop isomeration aren't far behind. 

You might get away with 4, hard short boils for gravity, colour and flavour but I believe smm (or dms) has a half life that requires time, regardless of volume. Modern malts have less precursor but with so many good resons for a proper length, I find it hard to be convinced that dropping below 60 is wise.

Not sure how protein coagulation behaves in shorter, intense, low volume boil.


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## good4whatAlesU (22/8/17)

Cool but once again I question the "regardless of volume" statement? Where is the data?


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## manticle (22/8/17)

The definition of 'half life' is time dependent.


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## good4whatAlesU (22/8/17)

Cool, but I'd like to read what the experimental procedures were during which the half life was determined? What was the ramp up to temp time, sampling and storage protocols prior to testing?
What volumes of wort (or liquid?). Many possible covariates.


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## manticle (22/8/17)

There's enough information there for you to do your own research.
You may end up deciding your short boul idea is fine.


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## good4whatAlesU (22/8/17)

I just like to see the data rather than dogmatically following a quoted figure who's experimental factors aren't being explained.
If someone has done the reading let us know or I'll try and get up to speed if time allows.
If the data doesn't exist on small volume boils I may find time to run some experiments and submit to the lab at my work.

Edit: This appears to be one of the papers many are quoting. Boil volume is not recorded in the methodology. It was a lager with two malts. 

http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1979.tb06845.x/pdf


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## Tony121 (22/8/17)

good4whatAlesU said:


> I may find time.....


.,,,,,for a longer boil.

Seriously though, if time is such an issue why don't you supplement with extract brews when the need arises?


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## Qualia (22/8/17)

So brewed a Tripel using the methods suggested last night. 

Setup my 2v HERMS the night before. Put a timer on so that the mash was at strike temp when I got home. Chilled overnight in Melbourne weather and the wort was 22c in the morning ready to pitch. Easy.

Next time though I'll mash in cold, as for some reason my kids don't respond to "you really need to go to sleep now as I have to dough in"?


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## good4whatAlesU (22/8/17)

I've got a ton of fresh AG ingredients eating a hole in my pocket... Would pain me to do an extract brew (not that I'm against it).


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## Sidney Harbour-Bridge (22/8/17)

I split my brew day at the boil, I bring the brew to a boil then seal up the kettle and leave overnight or longer, it is sterile at this point and will not go off, when I resume the boil it is sterilized again, it also seems to drop out more hot break this way.


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## good4whatAlesU (22/8/17)

This one's methodology is slightly better,volume is provided: e.g. (500 mL) but uses an unidentified 'lager' malt.

However, it also states that the boil was "under reflux" which means that volatiles were not allowed to escape the vessel (no evaporation) so I'm not sure how close to real world that is likely to be. I'm not sure why reflux was used, possibly because boiling such a small volume could not have continued for the time frame of the experiment. However the technique could have influenced the results. 

/Dickenson-1979-Journal_of_the_Institute_of_Brewing.


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## klangers (22/8/17)

If you're looking to accelerate the reactions in the boil, then it would be worth understanding the reaction kinetics (if anyone's actually done that research; it would be rather difficult). I think what a lot of people in this thread are angling at is: Yes, there is no data regarding boil volume, but the fundamentals of chemical reactions are well understood. Vessel volume does NOT have a direct influence on reaction kinetics. The only way it would affect it is via mass flow characteristics (increased the interaction rate of the molecules from differing boil seeding and convection), which is indirectly. This would only increase the reaction rate if the reaction is indeed limited by the work input. However, like most reactions, my understanding is that the SMM--> DMS is an equilibrium reaction, and that the reaction rate is primarily dependent on temperature. (EDIT: Try a pressure cooker to get a higher temperature and faster reaction?)

While I understand you want to (dis)prove your hypothesis, I believe a more holistic optimisation approach would be better.

Eg, you may find that an external boiler with a kettle pump will give you higher energy efficiency and mimic higher boil intensity due to the far greater turbulence. This is in fact how industrial brewing kettles work (they are often under partial vacuum with vapour recovery too).


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## Lionman (22/8/17)

What it boils down to (yeah nice pun) is that most research is aimed at commercial practices to ensure customers receive the best possible product while production costs are kept as low as possible. If commercial brewers could get a way with shorter boils, which would significantly reduce their energy expenditure, then they would.

Home brew is a different kettle of fish (pushing it with that one) altogether. You can get a way with some shortcuts with home brew and still have acceptable beer.

If you wan tot strive for the best beer you can make, then I wouldn't recommend shortcutting things like boil times. If you want to make acceptable beer in less time to improve your brew/life balance, then I say go for it.

Worse thing that can happen is that the beer is sub par.


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## Lionman (22/8/17)

If your interested in spreading a brew over multiple days, maybe consider over night mash.

Mash in just before bed, set at around 70c, insulate well. Will probably be sitting at about 63c or so in 7-8 hours time. Sparge and boil. You should have a cube filled within 2 hours the next morning.

Fill brewery
Heat liquor
Mill grain
Mash in

Sleep *zzzzzzzzzzzzzz

Sparge
Boil
Cube
Clean

Pitch when your ready.

You can have multiple cubes ready to go too so you can keep your fermenter going. It's easier to find time to pitch as it doesnt take long. Brew when you can, even if you're well stocked because you can never have too much wort ready to go. Do back to back brew if you plan to spend a day brewing.


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## Adr_0 (22/8/17)

This study doesn't really say much more, except the obvious high temperature = faster breakdown of SMM to DMS:
http://onlinelibrary.wiley.com/doi/10.1002/jib.156/pdf

It also backs up a ~30min half life of SMM at 98.5°C.

It's quite possible that you can exceed 100°C in the lower areas of your kettles, though I think this is more likely in a taller kettle. The additional convection will help big-time with the actual boiloff of DMS though - so my scientificish opinion is that no-chilling with a reduced boil would lead to more SMM hanging around and being metabolised to DMS by the yeast, = bad.

Keep in mind as well that different malts have different amounts of SMM to begin with. Gladfields pils, in a few beers I tasted, seemed to have a heap. A well modified, lightly kilned malt will have the 'most' amount of SMM vs a less modified, darker malt (which has been kilned at higher temperature - the kilning driving off some DMS). So your Weyermann Munich II will have bugger all, whereas some of your extra-pale pils will likely have a lot.

Keep the malt in mind when doing your recipes and you may get away with it. With a pale pils, 30min boil and no-chilling though I KNOW that you will have DMS issues.


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## Adr_0 (22/8/17)

good4whatAlesU said:


> I just like to see the data rather than dogmatically following a quoted figure who's experimental factors aren't being explained.
> If someone has done the reading let us know or I'll try and get up to speed if time allows.
> If the data doesn't exist on small volume boils I may find time to run some experiments and submit to the lab at my work.
> 
> ...



Table IV in this study is interesting as it puts the SMM and DMS in ug/L terms, rather than 'equivalence'. Straight away, SMM is 164g/mole and DMS is 64g/mol so conversion of 1 SMM mole will result in DMS being 0.4x the ug/L of the SMM.

During the boiling stages the DMS level is much lower than 0.4x the SMM level (taking the 11min numbers of 305 and 18), suggesting that it's basically instantly boiled off - and suggesting that the limiting factor of the removal chain is the conversion of SMM to DMS.

Given there is a half life of 30min at 98.5°C, you should focus on your malt selection and your boil temperature (assuming you will ignore the recommended time advice). Ironically I would suggest that a taller kettle is a solution for a greater temperature as you should be greater than 100°C at the bottom of the kettle.


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## good4whatAlesU (22/8/17)

klangers said:


> If you're looking to accelerate the reactions in the boil, then it would be worth understanding the reaction kinetics (if anyone's actually done that research; it would be rather difficult). I think what a lot of people in this thread are angling at is: Yes, there is no data regarding boil volume, but the fundamentals of chemical reactions are well understood. Vessel volume does NOT have a direct influence on reaction kinetics. The only way it would affect it is via mass flow characteristics (increased the interaction rate of the molecules from differing boil seeding and convection), which is indirectly. This would only increase the reaction rate if the reaction is indeed limited by the work input. However, like most reactions, my understanding is that the SMM--> DMS is an equilibrium reaction, and that the reaction rate is primarily dependent on temperature. (EDIT: Try a pressure cooker to get a higher temperature and faster reaction?)
> 
> While I understand you want to (dis)prove your hypothesis, I believe a more holistic optimisation approach would be better.
> 
> Eg, you may find that an external boiler with a kettle pump will give you higher energy efficiency and mimic higher boil intensity due to the far greater turbulence. This is in fact how industrial brewing kettles work (they are often under partial vacuum with vapour recovery too).



Interesting, I did chance upon one kinetics paper from 2015 I think .. but will need more brain power (and sleep) to interpret. Agreed the higher boil intensity (under vacuum or pressure) is interesting and as ^Adr_0 suggests increasing temps beyond (above 100 oC). I've in mind buying a few disposable plastic kettles from Big W ($7.00 each) and having a play around.

Vessel volume can have a volume on kinetics at the extreme.. that is (sorry I'm playing devils advocate) for example boiling 1 mL for 90 minutes, will result in not very much DMS or SMM (or anything) - only a burnt residue. edit; that is why the early papers with low volumes appear to have run their experiments under reflux (so they didn't run out of liquid).


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## Adr_0 (22/8/17)

Adr_0 said:


> Table IV in this study is interesting as it puts the SMM and DMS in ug/L terms, rather than 'equivalence'. Straight away, SMM is 164g/mole and DMS is 64g/mol so conversion of 1 SMM mole will result in DMS being 0.4x the ug/L of the SMM.
> 
> *During the boiling stages the DMS level is much lower than 0.4x the SMM level (taking the 11min numbers of 305 and 18), suggesting that it's basically instantly boiled off - and suggesting that the limiting factor of the removal chain is the conversion of SMM to DMS.*
> 
> Given there is a half life of 30min at 98.5°C, you should focus on your malt selection and your boil temperature (assuming you will ignore the recommended time advice). Ironically I would suggest that a taller kettle is a solution for a greater temperature as you should be greater than 100°C at the bottom of the kettle.



I should correct this to changes in SMM vs DMS, and include the periods where it's boiling and where it's not. Very interesting, but still the same point that SMM->DMS is the limiting reaction:





So during the boiling stages there is significant reduction in DMS, significantly less than the 64:164 ratio, so my point still remains correct.

The stages either side show an increase in DMS with a reduction in SMM which suggests the SMM is being broken down to DMS - and fairly slowly. There is also a fixed starting quantity of SMM per batch that you need to burn through, so, funnily enough, if you boil for long enough you'll break all the SMM down and boil off all the DMS.

Apparently the sensory threshold is 33ppb, FYI.


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## klangers (23/8/17)

good4whatAlesU said:


> Interesting, I did chance upon one kinetics paper from 2015 I think .. but will need more brain power (and sleep) to interpret. Agreed the higher boil intensity (under vacuum or pressure) is interesting and as ^Adr_0 suggests increasing temps beyond (above 100 oC). I've in mind buying a few disposable plastic kettles from Big W ($7.00 each) and having a play around.
> 
> Vessel volume can have a volume on kinetics at the extreme.. that is (sorry I'm playing devils advocate) for example boiling 1 mL for 90 minutes, will result in not very much DMS or SMM (or anything) - only a burnt residue. edit; that is why the early papers with low volumes appear to have run their experiments under reflux (so they didn't run out of liquid).



That isn't the effect of vessel volume as such, it's specific boiling power (watts/kg). You'd get the same effect if you kept a 20L boil and made the power 200 kW or something crazy.


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## good4whatAlesU (23/8/17)

klangers said:


> That isn't the effect of vessel volume as such, it's specific boiling power (watts/kg). You'd get the same effect if you kept a 20L boil and made the power 200 kW or something crazy.



Cool, but would not gravimetrically (watts/ kg) or volumetrically (watts/ litre) be legit? Why must it be gravimetrically only? If volumetrically is legit than vessel volume plays a part. 

Edit: Hopefully getting some costing from the lab this week for DMS and SSM analysis. If anyone is interested I can possibly PM. Idea for my own interest is to do a very short vigorous, low volume boil with my usual base malt and see what's what instead of cogitating. Will take samples every 2 minutes or so for 20 minutes (something like that).


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## klangers (23/8/17)

Yeah, you can do it that way. I personally wouldn't because thermodynamics works on mass - volume is not really ever used for this kind of analysis. Specific heat capacity, latent heat capacity etc etc is all expressed as mass-based so your watts/L is just watts/kg divided by density. But that's still specific boiling power, whether it be watts/kg or watts/litre. Vessel volume doesn't play a _direct _role is all I'm saying. You need to analyse it more "pure" metrics.


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## good4whatAlesU (23/8/17)

Agreed from a theoretical viewpoint, but the real world size / shape/ surface area/ smoothness etc. must play an influence?

Anyway, apologies guys for being pedantic. I'll stop flogging a dead horse. If the opportunity arises - I'll just do some shorter low volume boils with my base malt and see if the DMS and SSM are below acceptable levels. If they are within spec then all good.


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