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donburke

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I have read quite a few of the 'overnight mash' threads, and its seems to work just fine as long as you maintain temp reasonably well

What i was thinking of doing was, mash, sparge and lauter tonight, with all of my wort in the kettle, and then boil briefly for 5 or 10 mins

Tomorrow morning, I could re-start my boil, hop addition, chill etc

I imagine that between say 10pm and 7am, my wort will have dropped probably no lower than 70 degrees, which should eliminate any concern of souring (90 odd litres in my kettle is a large thermal mass and tends to hold temp quite well)

My concern is, would I be creating any undesirable compounds letting the wort sit overnight ? In particluar, DMS as its a kolsch using the weyermann premium pilsner malt, which i understand is prone to DMS. Would the 90 min boil the following morning eliminate the DMS and/or it's precursors ?

Is there any reason that the more learned brewers would advise against this ?

thanks
 
Thinking out aloud here but the precursor to DMS is the SMM from the malting process

Stolen from Homebrew wiki
"The level of SMM in malt is responsible for the DMS level in wort. During mashing the SMM, DMS and very soluble DMSO are brought into solution. No SMM is hydrolized to DMS at this time.

Kettle boiling hydrolizes SMM to DMS which is removed during evaporation. The half life or time needed to remove half of the DMS is 40 minutes so that three-fourths is removed in 90 minutes. Narssis recommends a 100 minute boil to reduce the level of SMM and DMS to acceptable levels in most beers.

The level of DMSO does not change during the kettle boil. A small amount of DMS, 0.4 ppb, may be contributed by hops, especially if added in large amounts late in the boil. As long as the wort is hot SMM will be converted to DMS. It is important to convert SMM to DMS in the kettle so that build up during the hot wort stand is minimized.

The following steps should insure low levels of DMS in the finished beer:

Boil the entire wort 90 minutes or longer
Ensure that the boil is vigorous - rolling
Allow at least 8% evaporation
Minimize the hot wort standing time
Rapidly cool the wort"
 
I have read quite a few of the 'overnight mash' threads, and its seems to work just fine as long as you maintain temp reasonably well

What i was thinking of doing was, mash, sparge and lauter tonight, with all of my wort in the kettle, and then boil briefly for 5 or 10 mins

Tomorrow morning, I could re-start my boil, hop addition, chill etc

I imagine that between say 10pm and 7am, my wort will have dropped probably no lower than 70 degrees, which should eliminate any concern of souring (90 odd litres in my kettle is a large thermal mass and tends to hold temp quite well)

My concern is, would I be creating any undesirable compounds letting the wort sit overnight ? In particluar, DMS as its a kolsch using the weyermann premium pilsner malt, which i understand is prone to DMS. Would the 90 min boil the following morning eliminate the DMS and/or it's precursors ?

Is there any reason that the more learned brewers would advise against this ?

thanks

I have done exactly that once, with a porter and all went fine with no detectable problems.

With a kolsch I might rethink as there is really nowhere in that style to hide any off flavours.

Apart from that I can offer no more advice.

Cheers
 
I would say, if anything the DMS would be less than what you would have on a normal boil schedule. Any DMS generated overnight will be boiled off fairly quickly, and there will be less SMM to convert as a result. You might even be able to get away with a shorter boil the next day.
 
Thinking out aloud here but the precursor to DMS is the SMM from the malting process

Stolen from Homebrew wiki
"The level of SMM in malt is responsible for the DMS level in wort. During mashing the SMM, DMS and very soluble DMSO are brought into solution. No SMM is hydrolized to DMS at this time.

Kettle boiling hydrolizes SMM to DMS which is removed during evaporation. The half life or time needed to remove half of the DMS is 40 minutes so that three-fourths is removed in 90 minutes. Narssis recommends a 100 minute boil to reduce the level of SMM and DMS to acceptable levels in most beers.

The level of DMSO does not change during the kettle boil. A small amount of DMS, 0.4 ppb, may be contributed by hops, especially if added in large amounts late in the boil. As long as the wort is hot SMM will be converted to DMS. It is important to convert SMM to DMS in the kettle so that build up during the hot wort stand is minimized.

The following steps should insure low levels of DMS in the finished beer:

Boil the entire wort 90 minutes or longer
Ensure that the boil is vigorous - rolling
Allow at least 8% evaporation
Minimize the hot wort standing time
Rapidly cool the wort"

thanks for that

the SMM is converted to DMS whilst the wort is hot, so having my wort sit hot is going to have the effect of building up levels of DMS, but how much ?

the SMM is still converted to DMS during boiling, but its evaporated in the boil, but perhaps too much may have built up overnight in that the 90 min boil will not be able to rid
 
I would say, if anything the DMS would be less than what you would have on a normal boil schedule. Any DMS generated overnight will be boiled off fairly quickly, and there will be less SMM to convert as a result. You might even be able to get away with a shorter boil the next day.

i suppose the long hot rest will exhaust, or at least significantly convert alot of the SMM to DMS, so this make sense

so the next morning, i have a bucket load of DMS in my wort, and not much more being created, but just how volatile is DMS and how easily does it leave the wort during the boil ?

so if i start off with say 10 times the normal pre-boil amount of DMS, is it mostly going to evaporate during the boil ? or will i still end up with 10 times the normal post-boil amount of DMS because i started off with significantly more ?
 
Well, given that the boiling point of DMS (on its own) is only 37 degrees, I would expect it boils off pretty quickly.
 
so if i start off with say 10 times the normal pre-boil amount of DMS, is it mostly going to evaporate during the boil ? or will i still end up with 10 times the normal post-boil amount of DMS because i started off with significantly more ?

The half life or time needed to remove half of the DMS is 40 minutes so that three-fourths is removed in 90 minutes.

Going from the article that Stormahead quoted, you end up with 10 times more at the end if you started with 10 times more, so you might want to consider a longer boil.
 
That wiki quote isn't 100% correct - the half life time of 40 minutes quoted there is the conversion (and hence removal) of SMM during the boil, not the removal of DMS itself. When you are boiling (as burke plans to again), the DMS goes away pretty quickly. It is SMM-DMS conversion post (in this case, post-2nd) boil that one has to be concerned about.
 
Having a young family taking up my time more these days I generally have a great Friday night mashing/lautering and spend early Saturday morning boiling/chilling while they're having breaky or watching the TV... by late morning it's all back to normal [happy wife happy life].

I've not noticed anything detrimental in any of the beers I've done this way. I have noticed though that in the winter, the hot wort drops considerably and in the morning it's around 40 degrees...

As a side note, what I do is make sure my kettle lid fits well. I put two or three layers of foil over the kettle top then push the lid into it and hold it down with my mash paddle to minimize losses.
 
That wiki quote isn't 100% correct - the half life time of 40 minutes quoted there is the conversion (and hence removal) of SMM during the boil, not the removal of DMS itself. When you are boiling (as burke plans to again), the DMS goes away pretty quickly. It is SMM-DMS conversion post (in this case, post-2nd) boil that one has to be concerned about.

Ah ok - that does actually make more sense that its the conversion of SMM to DMS and not the boiling off of DMS that takes that long.
 
So donburke, did you give this a shot? How did it go?

I'm thinking about doing this myself, only BIAB. I want to mash and mash out, then boil for maybe 10 minutes or so, seal her up and leave overnight.

There are a lot of posts on overnight mashing, but not too many doing it this way.

EDIT: Scratch that last comment, there are heaps of posts about mashing one day and boiling the next. Opinion seems pretty mixed though. Some say they've done it plenty of times and it turned out great, others say it shouldn't be done.

I guess I just need to try it and see how it turns out myself. :)
 
Well, I'm giving it a shot tonight. I'm brewing DrSmurto's English IPA - http://www.aussiehomebrewer.com/forum/inde...amp;recipe=1481

Mashing as we speak, going to mash out after 90 min as per the recipe, and do a quick 10-15 minute boil to kill any nasties and seal it up until tomorrow. I could probably do it all tonight but want to see how it goes so that I can do the same again if all goes well...fingers crossed.
 
It'll work fine. I'd even hazard to say you only need to bring it to 75-80C for a few minutes to kill and maim any critter that would do anything to it in 12 hours.

I pretty much always leave my BIABag hanging from its dripping point with a bowl below it to catch any post-squeeze drips. Usually there about 100-200ml of wort in there the next day ... and it's never sour. Day after that though - YIKES!

EDIT: I kettle chill overnight and have never had an issue with it.
 
i've done this a few times with no worries.
the time when i didn't get around to it for three days was interesting.... i made the beer anyway and got a sour brown ale. it really was very sour indeed...
 
It's done, all sealed up with glad wrap and covered in blankets to try to avoid too much heat loss, to make it easier to boil up again tomorrow.

I thought the sourness was caused by nasties in the wort when left overnight. The boiling for 10 minutes should prevent this right?

EDIT: I kettle chill overnight and have never had an issue with it.

Ever had a problem with chill haze doing this Nick?
 
So donburke, did you give this a shot? How did it go?

I'm thinking about doing this myself, only BIAB. I want to mash and mash out, then boil for maybe 10 minutes or so, seal her up and leave overnight.

There are a lot of posts on overnight mashing, but not too many doing it this way.

EDIT: Scratch that last comment, there are heaps of posts about mashing one day and boiling the next. Opinion seems pretty mixed though. Some say they've done it plenty of times and it turned out great, others say it shouldn't be done.

I guess I just need to try it and see how it turns out myself. :)

i didnt end up doing it, was concerned that a kolsch was not the style to try it on, as there is little to hide behind
 
Maybe it's a good style to try it on, since flaws are more easily identified ... As long as you're prepared to waste a potentially unwanted brew.
 
Maybe it's a good style to try it on, since flaws are more easily identified ... As long as you're prepared to waste a potentially unwanted brew.

good point, but the batch size was 80 litres, so maybe experimenting with a 20 litre batch of kolsch is a good idea
 
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