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General Category => All Grain Brewing => Topic started by: mdkbrew on March 11, 2011, 10:51:30 PM

Title: Time Delay from Mash to Boil
Post by: mdkbrew on March 11, 2011, 10:51:30 PM
Brewers,

Has anyone ever tried delaying the time between wort collection after a mash and the actual boil?  If so, what are the issues you've run into? 

I'm trying to economize the length of time on my brew days and am thinking of splitting the mash/wort collection and actual wort boil between two days; i.e. do my mash/wort collection at night, then let the wort sit in a covered brew pot and start the boil the next morning.

Anyone have any luck with this before?  How has this affected your beers?

Thanks as always for your input!

Matt
Title: Re: Time Delay from Mash to Boil
Post by: tschmidlin on March 11, 2011, 10:57:32 PM
I haven't done it, but I've heard from people who have tried it.

If you are brewing a sour beer then go for it, otherwise you'll probably want to boil it briefly before you put it away for the night.

But I think if you really want to save time, you should brew extract/steeping grains until your schedule frees up again.  :)
Title: Re: Time Delay from Mash to Boil
Post by: HydraulicSammich on March 11, 2011, 11:00:07 PM
I have done that many times without problem.  Split the brew into two days,  Just sanitized the lid and seal and refrigerated.  Obviously, you do run an increased risk of infection.  
Title: Re: Time Delay from Mash to Boil
Post by: tschmidlin on March 11, 2011, 11:05:42 PM
I have done that many times without problem.  Split the brew into two days,  Just sanitized the lid and seal and refrigerated.  Obviously, you do run an increased risk of infection. 
You didn't notice any tartness from the lactobacillus on the grains that survive the mash?  The people I've spoken to who tried it thought it was noticeable.
Title: Re: Time Delay from Mash to Boil
Post by: HydraulicSammich on March 11, 2011, 11:20:28 PM
I have done that many times without problem.  Split the brew into two days,  Just sanitized the lid and seal and refrigerated.  Obviously, you do run an increased risk of infection. 
You didn't notice any tartness from the lactobacillus on the grains that survive the mash?  The people I've spoken to who tried it thought it was noticeable.

I have not noticed any changes.  However, most of my beers are hoppy and have only been brewing for a year or so.  They taste good to me.
Title: Re: Time Delay from Mash to Boil
Post by: tschmidlin on March 11, 2011, 11:25:01 PM
I have not noticed any changes.  However, most of my beers are hoppy and have only been brewing for a year or so.  They taste good to me.
That's what counts :)
Title: Re: Time Delay from Mash to Boil
Post by: bluesman on March 12, 2011, 01:16:01 AM
I haven't personally done this but I know some brewers that do without any adverse effects to the finished beer. This is assuming a two day process window.

You should be fine.
Title: Re: Time Delay from Mash to Boil
Post by: Will's Swill on March 12, 2011, 01:42:58 AM
Admittedly, my buddies and I are the three stooges of brewing.  The last time we got together and brewed we had the first batch go well (extract pils, set-up to clean in 2.5 hours), thought we were going to have a smooth brew day, when things started to go wrong.

A six (6!) hour mash (still didn't completely convert), a leaky propane connection, two broken thermometers (one in a finished, cool kettle of wort), set the dog on fire - twice, an immersion chiller that wouldn't cooperate, dramatically dropping temperatures, and an overnight pause before getting the last boil in, and we finally got the remaining three batches complete.

That last bit about the overnight pause - that gives me a side-by-side comparison as I did two of the same batches that day, completing the first, but with all the other ^*%*&% happening, it got dark and cold, and I had a house full of people to entertain, so I delayed the boil of the second batch after completing the sparge.  I just put Saran wrap over the keggle and moved it inside.

I'll be bottling this weekend, so I'll taste both and give you an update.
Title: Re: Time Delay from Mash to Boil
Post by: Hokerer on March 12, 2011, 02:57:13 AM
...set the dog on fire - twice,...

LOL, that must have been one heck of a brew day :)
Title: Re: Time Delay from Mash to Boil
Post by: brewsumore on March 12, 2011, 04:47:32 PM
If you are going to wait between mashing the wort and boiling it, be sure to do an effective mashout to stop the conversion process.  Personally it's not something I would want to do.
Title: Re: Time Delay from Mash to Boil
Post by: a10t2 on March 12, 2011, 04:56:04 PM
You should be fine for at least 24 hours. I've done a few pre-boil wort stability tests, and haven't observed any growth or gravity drop on the second or third day. Like brewsumore said, though, without an effective mashout (>15 min at >75°C) you'll change the fermentability profile of the wort.
Title: Re: Time Delay from Mash to Boil
Post by: brewsumore on March 12, 2011, 05:02:32 PM
You should be fine for at least 24 hours. I've done a few pre-boil wort stability tests, and haven't observed any growth or gravity drop on the second or third day. Like brewsumore said, though, without an effective mashout (>15 min at >75°C) you'll change the fermentability profile of the wort.

I'm sure you meant (>15 min at >75°F)  Thanks for the clarification I omitted.  I generally skip a mashout since I go straight to the kettle.  And it's interesting that the wort stays stable for a day - good to fall back on in the event of the unforeseen on brew day!
Title: Re: Time Delay from Mash to Boil
Post by: denny on March 12, 2011, 05:58:24 PM
A six (6!) hour mash (still didn't completely convert)

I'll bet it did. Were you using the iodine test to decide if it had converted?
Title: Re: Time Delay from Mash to Boil
Post by: Hokerer on March 12, 2011, 06:52:39 PM
I'm sure you meant (>15 min at >75°F)  Thanks for the clarification I omitted.

No, he really meant >75°C   Mashout is normally around 168°F
Title: Re: Time Delay from Mash to Boil
Post by: brewsumore on March 12, 2011, 07:06:32 PM
I'm sure you meant (>15 min at >75°F)  Thanks for the clarification I omitted.

No, he really meant >75°C   Mashout is normally around 168°F


 ::) doh!  Sorry, my head is clogged with a bad cold today - well that's my excuse anyway.  I was actually thinking that, conversion isn't stopped dead in its tracks until +170F, but IIRC, it's above that temp you start to get too much tannin extraction??
Title: Re: Time Delay from Mash to Boil
Post by: Hokerer on March 12, 2011, 07:29:27 PM
::) doh!  Sorry, my head is clogged with a bad cold today - well that's my excuse anyway.  I was actually thinking that, conversion isn't stopped dead in its tracks until +170F, but IIRC, it's above that temp you start to get too much tannin extraction??

Tannin extraction depends on both temperature and pH.  That is, even if you let the temp get too high, tannin extraction won't be a problem unless the pH is also too high (>6.something, I can't remember exactly).  Most all the time, your mash pH is less than that so accidentally going too hot isn't a huge concern.
Title: Re: Time Delay from Mash to Boil
Post by: brewsumore on March 12, 2011, 08:13:50 PM
It is pH above 6 you extract excessive phenols and tannins from the mash (Palmer pg. 159).

So I'm thinking that if you are planning to leave your mash runoff for 24 hrs before boiling, maybe you would want to take it to =/+170F, which would prevent further extraction during the following sparge, but would definitely shut off the conversion process. ???
Title: Re: Time Delay from Mash to Boil
Post by: denny on March 12, 2011, 09:35:33 PM
It is pH above 6 you extract excessive phenols and tannins from the mash (Palmer pg. 159).

So I'm thinking that if you are planning to leave your mash runoff for 24 hrs before boiling, maybe you would want to take it to =/+170F, which would prevent further extraction during the following sparge, but would definitely shut off the conversion process. ???

It sounds like the OP is going to collect all the wort before leaving it overnight. 
Title: Re: Time Delay from Mash to Boil
Post by: brewsumore on March 12, 2011, 09:38:55 PM
I see, so if you are interested in killing off conversion processes, collect combined mash and sparge runoffs, and heat that to 170F prior to cooling, to protect your fermentability profile.   :)
Title: Re: Time Delay from Mash to Boil
Post by: Hokerer on March 12, 2011, 09:43:34 PM
I see, so if you are interested in killing off conversion processes, collect combined mash and sparge runoffs, and heat that to 170F prior to cooling, to protect your fermentability profile.   :)

Or do a real "mash out", that is, heat the mash grain bed to 170F for 15 minutes and then run it off and store it.
Title: Re: Time Delay from Mash to Boil
Post by: denny on March 12, 2011, 09:48:06 PM
I see, so if you are interested in killing off conversion processes, collect combined mash and sparge runoffs, and heat that to 170F prior to cooling, to protect your fermentability profile.   :)

Or do a real "mash out", that is, heat the mash grain bed to 170F for 15 minutes and then run it off and store it.

That won't pasteurize your wort, though.  If you heat it to 170 in the kettle and hold it for 10 min., theoretically you'll kill off wort spoiling bacteria.
Title: Re: Time Delay from Mash to Boil
Post by: Will's Swill on March 13, 2011, 02:09:37 AM

I'll bet it did. Were you using the iodine test to decide if it had converted?

Yep.  After an hour the iodine instantly turned black.  It gradually took longer to turn black until after six hours it took maybe 30 seconds to a minute.  I called that good enough.  I was using grain that was well over a year old (bought two fifty # bags of 2 row becuase the price was great, but didn't quite get through the second...), and a lot of popcorn as an adjunct.  Not a good combination I guess.
Title: Re: Time Delay from Mash to Boil
Post by: Hokerer on March 13, 2011, 04:21:20 AM
That won't pasteurize your wort, though.  If you heat it to 170 in the kettle and hold it for 10 min., theoretically you'll kill off wort spoiling bacteria.

Good point, I was only focused on stopping the enzymes.  Completely missed the spoilage bit.
Title: Re: Time Delay from Mash to Boil
Post by: Will's Swill on March 15, 2011, 04:09:20 AM
OK, the resuts are in on my inadvertant test on the effects of an overnight delay between mash and boil.  My intent on brew day was to split the runnings from a single mash into two boils.  ("Why?" you may ask.  I was intending to test for any effect on taste when using a counterflow chiller vs. an immersion chiller as the result of a conversation on another forum.  There was no intent to wait overnight for one boil at the outset, but the brew day was a disaster...)  I don't perform a mash out when I brew and I did not heat the wort beyond the mash temp before putting up for the night, nor was the wort insulated.  I essentially used my keggle as a lauter grant to accumulate the runnings, mixed thoroughly, ran off half into another smaller kettle, and then executed one boil immediately to make Hop You Now.  I covered the keggle with the remaining wort with Saran Wrap and moved it inside overnight.  The next morning I performed the exact same boil to make Hop You Later.

Some vital stats:

Hop You Now - O.G. 1.062, F.G. 1.008 (CFC if you care)
Hop You Later - O.G. 1.059, F.G. 1.009 (IC)

So I don't think fermentability was affected by the overnight delay.  While bottling yesterday, I took samples of both and my wife poured me a double-blind triangle test.  I was able to correctly identify both the two samples that were the same and which batch they came from, but...  Hop You Now was noticeably darker than Hop You Later, so I'm pretty sure that that biased my result.  So I did another double-blind triangle test but this time in opaque glasses (does that make this triple-blind?).  In this arrangement I was unable to separate the two batches.

Unfortunately, I have no idea why one would be darker than the other.  Maybe something to do with settling overnight, but my keggle has a dip tube that leaves almost nothing behind when I drain it, so I wouldn't think so.
Title: Re: Time Delay from Mash to Boil
Post by: euge on March 15, 2011, 06:06:02 AM
The darkening might be oxidation. Anyway, it's worth another for repeatability- right?

Sometimes I'll leave wort to chill in a water bath overnight. So far it's been no problem. To me it seem that if you turn the flame off, and put the lid on it's gonna be sterile in there until it is opened again. At least for our purposes a couple days.

Thanks for the inadvertent experiment. So there was no difference due to chilling methods? Maybe this is the source of the darkening? WAG.
Title: Re: Time Delay from Mash to Boil
Post by: Hokerer on March 15, 2011, 01:14:26 PM
Some vital stats:

Hop You Now - O.G. 1.062, F.G. 1.008 (CFC if you care)
Hop You Later - O.G. 1.059, F.G. 1.009 (IC)

It sounds like you ran off into one container, mixed it well, and then split it in two?  How then did you end up with two different OG readings?  I'm confused.
Title: Re: Time Delay from Mash to Boil
Post by: Will's Swill on March 15, 2011, 10:45:05 PM
Darkening due to oxidation may be possible, or maybe it is chilling method (I kinda doubt either, though).  I did aerate Hop You Now the night I boiled it by pouring it back and forth from a carboy to a bucket, but I didn't pitch the yeast.  I wanted to pitch the yeast into both batches at the same time and temperature.


It sounds like you ran off into one container, mixed it well, and then split it in two?  How then did you end up with two different OG readings?  I'm confused.

Right, I suspect it was not mixed as well as I would have liked, and I got some density stratification in the lauter grant (keggle).  If so, the first batch that I ran off from the bottom of the container - Hop You Now - would be expected to have a higher gravity, though they are pretty close.

The implication here is that there's no taste difference between the IC chilling and the CFC chilling either, but if I did adversely effect Hop You Now through oxidation, the detrimental flavors may not have come out yet.  Time will tell...
Title: Re: Time Delay from Mash to Boil
Post by: mdkbrew on March 16, 2011, 08:04:25 PM
Thanks everyone for your input.  It certainly seems some experimentation is in order.  Cheers!
Title: Re: Time Delay from Mash to Boil
Post by: Will's Swill on April 26, 2011, 12:15:16 AM
So I may have spoken too soon about there being no difference between Hop You Now and Hop You Later.  I've been drinking them for a while now and haven't detected a difference except for more haze in Hop You Later.  But...

A brewing buddy of mine who has moved out of state was back in town this weekend.  So naturally we got together Saturday night and drank some homebrew.  Just for fun I set up a couple of double-blind triangle tests.  One was Hop You Now v. Hop You Later in opaque glasses (the other was US-05 v. WB-06 in a pumpkin wheat).  To my surprise, two out of three tasters could separate the two lagers.  Now remember that I originally had brewed these as a side-by-side comparison of the effects of chilling technique on taste, CFC v. IC.  If there was a difference at all, I expected the IC to have less DMS and more hop aroma.  However, though they tasted very similar, the CFC beer (Hop You Now) had a rounder, more pleasant bitterness, and a more floral aroma.  In addition, the IC beer (Hop You Later) had what was described as a very subtle sourness.  I think perhaps it picked that up in the overnight wait for the boil, as I can't imagine that this was caused by the chilling technique.

I'll have to repeat the experiment to separate out the effects of the chilling technique from the overnight wait prior to boil.