If you can get hold of a copy of DL's 'Big book of brewing' read his 'Brewers bed time story' about Alf and Betty Amylase, it answers the questions regarding the effect of mash stiffness, why to continue after starch end point, what's happening in a long to mash, temp' etc in am amusing story.
Its a bit long but I could post it if anyone is interested.
He also states that 75% of his brews are were mashed overnight (8-10hrs) not because of inferior grains but as the above story illustrates, for very sound reasons.
The effect of mash consistancy on efficiency?
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PieOPah
The Big Book of Brewing was my bible when I first started mashing (and I still refer it frequently!).
However, it was written in th 70s and homebrewing technique has advanced since then - though the principles are the same.
We've had debates before on here about mashing overnight (which is something I've never tried personally); the advocatesof it seem to get good results. The theories seem to predict more tannins would be extracted from the grain. Maybe some water supplies are more 'overnight mash' friendly than others. Or maybe the fall in temperature stops tannin extraction from being a problem. Who knows?
I think the bottom line is, find what works for you, with your water, your equipment and your lifestyle (not everyone wants to start brewing late at night!).
Scooby, you can't post anything taken straight from a book here for copyright reasons.
However, it was written in th 70s and homebrewing technique has advanced since then - though the principles are the same.
We've had debates before on here about mashing overnight (which is something I've never tried personally); the advocatesof it seem to get good results. The theories seem to predict more tannins would be extracted from the grain. Maybe some water supplies are more 'overnight mash' friendly than others. Or maybe the fall in temperature stops tannin extraction from being a problem. Who knows?
I think the bottom line is, find what works for you, with your water, your equipment and your lifestyle (not everyone wants to start brewing late at night!).
Scooby, you can't post anything taken straight from a book here for copyright reasons.
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PieOPah
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Seveneer
I have thought about this but with the 87% I got the other night I don't think this is the reason for it. I suppose a few more batches will show whether there's a problem with this approach.DaaB wrote:Just a thought, using a kettle element fired heat exchanger couldn't be briefly raising the temperature above the mid 70's and killing off the enzymes could it?
/Phil.
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PieOPah
I always thought that 60 minutes for a mash was the standard?
I have no problem with mashing for longer. The first beer I made was a stout so this is a nearlly impossible one to show any haze (although if drank before ready it can look like sewerage).
My next beer I screwed up and ended up with a lot of gunk in the fermenter that should have been filtered out (I stirred to try and cool quicker - didn't leave to settle long enough). Still, while a pint isn't crystal clear, it is good enough for me and tastes okay.
The last beer I made is still in secondary (due to bottle it tomorrow) so I can't judge on that one although I did have some problems but this was because the hop filter fell off during the boil (I guess I knocked it off when stiring - time for a jubilee clip - I guess they will be okay in the boil??)
I have a few things planned for my next brew (such as working out EXACTLY how much water is absorbed by my grain) so hopefully it will produce the best beer yet (although I am damn impressed with the stout and gutted that it has nearly run out). I may leave the mash for 90 minutes this time and see what improvements it makes.
I have no problem with mashing for longer. The first beer I made was a stout so this is a nearlly impossible one to show any haze (although if drank before ready it can look like sewerage).
My next beer I screwed up and ended up with a lot of gunk in the fermenter that should have been filtered out (I stirred to try and cool quicker - didn't leave to settle long enough). Still, while a pint isn't crystal clear, it is good enough for me and tastes okay.
The last beer I made is still in secondary (due to bottle it tomorrow) so I can't judge on that one although I did have some problems but this was because the hop filter fell off during the boil (I guess I knocked it off when stiring - time for a jubilee clip - I guess they will be okay in the boil??)
I have a few things planned for my next brew (such as working out EXACTLY how much water is absorbed by my grain) so hopefully it will produce the best beer yet (although I am damn impressed with the stout and gutted that it has nearly run out). I may leave the mash for 90 minutes this time and see what improvements it makes.
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Scooby
Probally down to 55C if the tun was well insulated. As long as the temp in the critical early stage was maintained then in an extended mash it makes no difference.PieOPah wrote:What type of temp losses would you be looking at with an 8 hour mash?
You would either need an external source constantly keeping the mash at temp
or
Mashing for that long makes no difference in temp
Daab is right, starch end point may occur after 45-60mins but the malt sugars needs to be broken down more to get the right balance of sugars in the wort.
Extended mashing produces more fermetable sugar but you can increase the mash temp slightly to compensate.
Sorry Jim, I realised that as soon as I hit submit. Can you recommend a 2000 version of DL's book?
Last edited by Scooby on Fri Oct 06, 2006 3:07 pm, edited 1 time in total.
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Seveneer
Right, the HLT elements are on and I'm going brewing. I'm going to aim for a similar mash consistancy to that I used on Wednesday and I'm going to hold it at 68C for 90 minutes.
Hoping for another high efficiency to go some way to proving to myself that my low efficiencies have been due to a thick mash.
I'll let you know how I get on.
/Phil.
Hoping for another high efficiency to go some way to proving to myself that my low efficiencies have been due to a thick mash.
I'll let you know how I get on.
/Phil.
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RabMaxwell
Hello all i have always got very high efficiency 
doesn't matter if the mash is thick or thin. I use a copper slotted manifold and a spinning sparge arm in my mash tun.I am actually experimenting by trying to reduce my efficiency to increase the maltiness of my brews.Cheers RabMaxwell(Brewing in Ayrshire)
doesn't matter if the mash is thick or thin. I use a copper slotted manifold and a spinning sparge arm in my mash tun.I am actually experimenting by trying to reduce my efficiency to increase the maltiness of my brews.Cheers RabMaxwell(Brewing in Ayrshire)-
Seveneer
I've always been in the 80% region myself until I set up the new shiny brewery. Since then I've had a few low numbers. That said, the last one came out at 87% with a thinner mash so I'm hoping to have made a start dialling in the new system. The actual figure is less important than consistancy. I'll let you know how I get on.
BTW, I also use a slotted copper manifold and sparge arm. Alway have and have never had any isssues attributable to these pieces of kit.
Doughing in in about 20 minutes....
/Phil.
BTW, I also use a slotted copper manifold and sparge arm. Alway have and have never had any isssues attributable to these pieces of kit.
Doughing in in about 20 minutes....
/Phil.
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beermonkey
OK, I guess it doesn't really matter so long as you like the beer , I have a friend who doesn't measure anything, just sticks the malt in a large stainless vessel on top of his solid fuel boiler from ' lunch time to tea time ' say 4 hours and makes superb beer.
Perhaps we all get a bit too fussy about this
back to my Friday evening H/B session after a long week commuting and working
beermonkey
Perhaps we all get a bit too fussy about this
back to my Friday evening H/B session after a long week commuting and working
beermonkey
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Seveneer
Good point Beermonkey.
I reckon my measuring is all over the place. I brewed on Wednesday and got 87% efficiency and used what I estimated to be 12 kg of pale malt from an unopened 25kg sack. I used the rest tonight and am well into the 90% range. I don't know what's going on but I do know I'm getting good efficiency with these thinner mashes.
/Phil.
I reckon my measuring is all over the place. I brewed on Wednesday and got 87% efficiency and used what I estimated to be 12 kg of pale malt from an unopened 25kg sack. I used the rest tonight and am well into the 90% range. I don't know what's going on but I do know I'm getting good efficiency with these thinner mashes.
/Phil.