Extended Mashing, Good, Bad, or RDWHAHB?

[Lilburgh]

I've been All Grain Brewing for about 9 months now, I'm still learning. I want to brew two 5 gallon batches this weekend and only Saturday will be above freezing. It usually takes me about 5-6 hours from start to clean up for 2 batches, all outside. I'm unable to start too early due to other commitments, and I don't want to still be outside when its dark and back below freezing. So my thoughts are to start mashing right before I leave the house in the morning. That would mean I would be mashing for about 2.5 hours in my 10 gal cooler before I can batch sparge. Is that too long of a Mash? I've heard some say that may be too long, but also heard some say their best beers came from overnight mashes (much longer than 2.5 hours). I'm curious what some of the opinions are here.

If its of any value, I'm brewing a Kolsch and an Imperial Red.

Thanks!

 

[revco]

I don't think that will be an issue, as long as you can retain relatively high temperatures during the 2.5 hours. (Your cooler mash tun should have no problem with that.) The problems can come when you drop below around 90 degrees, as this opens a window for many undesirables to go to town...but even those would take some time to establish themselves and the boil would kill them off anyway. Sometimes, an extended mash is called for...such as with sour mashing...then you're talking literally 48+ hours in the mash tun. So, I think you'll be fine.

You might find when you go to sparge that the temp drop you'll see will throw off your sparge temps a bit, but it you do a double sparge, a second sparge should get you relatively close to mash out temps.

Hope that helps!