QUOTE (tribs @ Apr 2 2006, 09:34 AM) Hi folks,
I already started mashing before I checked back with this forum. So, I mashed overnight anyway
You did get me a little bit worried though, so I searched around before I found this link.
http://www.brewboard.com/index.php?showtopic=30815
It seems you don't have to worry about the beta-amylase converting all the dextrins because they become denatured before the temperature drops to their working range. Apparently, temperature and pH are the variables that are of concern regarding tannin extraction, so that should not be a problem either.
I've done a long mash before (not overnight) and the results were great. The only side effect being excellent efficiency. 86% on that occasion.
I will not know the effects of the overnight mash until I bottle it in a couple of weeks (unless I get my kegs first) so we will wait and see.
FYI:
Starting Temp ~66C @ 1am
Finishing Temp ~63C @ 7:30am
Effieciency was 81%
If all is ok, then this technique is perfect for me. My brew day was over before lunch (which makes a change). My wife couldn't complain about wasting the weekend :huh: and I've got more time with my 14 week old girl, Molly
Well, I remain to be convinced!
According to David Line (who, incidentally, also advocated overnight mashes) alpha amylase can also break down dextrins into maltose, though at a very low efficiency.
Also, if you accept that all the enzymes stop working after 2hrs, what you're really doing is having a (fairly) normal length mash (therefore no increased efficiency) and then leaving your goods to stew for several hours, therefore extracting tannin (which I'm personally convinced will happen).
Having thus pontificated on the matter, however :rolleyes: , I must admit that I have never done an overnight mash, so I'm not speaking from experience, so I'd like to hear how your brew turns out, Tribs!