So do you guys mash for a set time period at a given temperature (with the time period given by a particular recipe) or do you measure the starch content in the mash (via iodine test) and keep the mash going until the test indicates that the mash is done ?
The reason I'm asking is that I've been reading the following www site :-
http://www.ongsbeer.com/Recipes.htm
(which is a good site BTW) and the guy has some really long mash times in his recipe write-ups. His mash technique as described on his site is of the latter style of the two above.
Mash duration
The main problem with very long mash times is that the balance of maltose and dextrins in the wort is upset.
Dextrins don't ferment as easily as maltose, so they account for the slight sweetness in the finished beer.
For English ale we're looking for around 75% maltose and 25% dextrin, and a number of factors affect the ratio. High mash temperatures tend to produce a higher proportion of dextrins, as does a high mash pH (i.e. less acidic).
Another factor is the mash time. Left long enough, the enzymes in the malt will convert nearly all of the dextrins into maltose. The result will be a very dry finished beer (which is fine if that's what you were after).
I mash for 90minutes and I always do a starch test, mainly because I've still got a bottle of iodine from my early mashing days. It gives you some reassurance that things are going alright.
There should be no starch left after about an hour, if you mash at around 66C.
Dextrins don't ferment as easily as maltose, so they account for the slight sweetness in the finished beer.
For English ale we're looking for around 75% maltose and 25% dextrin, and a number of factors affect the ratio. High mash temperatures tend to produce a higher proportion of dextrins, as does a high mash pH (i.e. less acidic).
Another factor is the mash time. Left long enough, the enzymes in the malt will convert nearly all of the dextrins into maltose. The result will be a very dry finished beer (which is fine if that's what you were after).
I mash for 90minutes and I always do a starch test, mainly because I've still got a bottle of iodine from my early mashing days. It gives you some reassurance that things are going alright.
There should be no starch left after about an hour, if you mash at around 66C.
