temp problem with my first all grain

ok, so i just started my first all grain batch. i'm doing a simple pale ale with a really simple grain bill. i'm using a coleman extrme 48 qt cooler for my mash tun. the other day, i put 170 degree water in it and it maintained that temp for 75 minutes before dropping a few degrees so i figured i was good to go. when i added my mash water, the temp of the mash stabilized at 154 degrees. perfect....or so i thought. 30 minutes later, the thermometer read 144. there is no way it should drop this much in 30 minutes. any ideas what might have gone wrong or what i could do to keep this from happening again. i guess i won't know how bad things went until i calculate my efficiency at the end.

Did you pre-heat the cooler? Were the grains room temperature?

i did preheat with 180 degree water for about 10 minutes. grains were room temp.

Did you stir things up good? Did you hit your OG? - Dirk

i've mashed in coolers before too. my first one, the temp dropped to around 130 after a 90 min. hold. i drained off about 1 gallon or so of mash liquid, heated it up to around 175 and poured it back in. then the temp went back up to where it should be. now, i mash in the kettle, put the coolers in the house overnight, then do the mash-out in them. but with the first one, the batch turned out fine. with yours, the temp was still in an enzyme favored temp, so you were still gaining fermentables (although it is going to lead to a dry beer). while the temp was dropping, you were in the alpha range for probably around 20 minutes or so. i've read that the main part of the conversion is over in about 15 min., so i think you will be good to go. like charlie says, 'relax and have a homebrew.'

good luck!

ok, so my efficiency ended up being 60% in the end. i hit a 1.044. i'm pretty upset. i guess i may have set my sights a bit high for my first AG. but, i have nowhere to go but up from here. it was a lot of fun though, and i look forward to my next brew. we'll just have to see how this one turns out. one thing i do know, it'll probably taste pretty darn good when ready!

there is nothing wrong with 60% efficiency on your first AG man. the important thing is you're learning YOUR system and all its pros and cons.

what was the strike water temp? are you using anything like promash? I like promash for figuring strike water temps and amounts. I just use the free/evaluation version right now, as its 'good enuf' for my level of experience.

My first AG hit 50%, but I get usually around 72% now. You just have to do a few batches to find a groove and know your equipment.

I'd just make sure you stir real good and make sure you're getting consistant temps. Then put the lid on and hold on for the best. Keep some extra hot water around incase you need to add it if you're losing temp.

Your cooler is a rectangular one I assume? I've heard of more people having troubles with those as far as hitting efficiency and keeping temps. I personally use a rubbermaid round cooler and although I only have 3 AG's under my belt I hit 75%, 70% and 80% efficiencies using beersmith to calc my strike water temps...