I have read and heard the majority of starch conversion happens within the first 20 minutes or so of the mash. I am actually doing a bit of research on this. So here are my questions.
I use beer smith and have it set to were it accounts for not preheating my mash tun. I use a 48qt picnic cooler and always do 5 gallon batches. I rarley take temp readings through out the mash, always at dough in though. But yesterday I was inclined to do so, when I doughed in I was hovering at 159, I poured some cooled water in to get it down to 154 (which is were I wanted it) I checked the temp again at about 30 minutes left in the mash it was already down to about 149*. I am begining to think that it is vital for me to maintain that desired temp through out the mash.
Doing 5 gal batches does leave me with a good pit of open space in the cooler.
Do you think this is vitally effecting the flavor of my beer? My effeciency is coming in good yesterday it was 86%
If by majority you mean 80% conversion, then yes. If you think its 100% then no it takes longer depending on a number of factors like mash ratio, crush, and temp.
My MLT loses a similar amount of heat during a long 90min mash, I wouldn’t worry about it too much. I think its more important when you are trying for a beer with a lot of body and mashing high like 158F. Then I’d do a shorter mash and kill the enzymes with a mashout. But normally this isn’t necessary for making good beer, in fact I like to make them drier and adjust my specialty grains to get the desired FG.
Preheating the tun with your strike water should minimize the temp drop, and you might consider a smaller tun that stays nearly full.
My first guess would be that the mash wasn’t thoroughly mixed and that you were reading 159°F because the thermometer was in a hot spot. I’ve found that I have to stir pretty vigorously for a couple minutes straight in order to get the mash to a uniform temperature.
My first guess would be that the mash wasn’t thoroughly mixed and that you were reading 159°F because the thermometer was in a hot spot. I’ve found that I have to stir pretty vigorously for a couple minutes straight in order to get the mash to a uniform temperature.[/quote]
