Breaking up a brew day

SWIMBO and the kids are demanding my presence in my ongoing efforts to be 2013 Father of the Year. This will take up from about 11:00 to about 3. I have a giant slugo of Bock yeast that I've been meaning to use for far too long, but haven't been able to schedule the brew day.

Fellow beernerds, please answer me the following question:

if I mash in the morning, sparge, and collect wort in the boil kettle and then cover it and leave it alone for say 4 or 5 hours, then come back, boil it and complete the brew day, will that work? Everything in my brain says it'll be fine, but I really don't want to put in the extra effort for this lager (decoction mashing, 90 minute boil, 45 degree chill, etc) if I'm just ****in the wort by letting it sit after mash.

I would do it, but I'd probably try and hit mashout temps just to make sure you don't have any issues. I've collected wort and stored in the fridge or outside and boiled the next day a couple of times. But there isn't likely to be any problems with bacteria over the course of just a couple of hours, especially at mash temps.

I've recently done this a few times. I researched the FDA pasteurization standards for fruit juices and 160F for 6 seconds will take care of any concerns so after I collect my wort I bring it to 160F, shut down and come back in the morning.

By that same logic milk is vat pasteurized at 145F for 30 minutes, which means if we were mashing milk it would be pasteurized. Oddly the next defined standard for milk is 161F for 15 seconds. I'm not sure why juice requires the high temp short time treatment, it seems that if is good enough for milk it should be good enough for juice. Maybe I just didn't read enough.

sounds like extract brewing is your friend at the moment.

I've collected my wort one day and boiled the next on several occasions and it has worked out well every time.

Can't think of anything that could go wrong, if the temp is brought high enough. Deactivating the enzymes and such.

Thanks guys. I ended up leaving my step mash at 158 for about 2 hours while i ran errands. Temp didn't drop below 156 in that time. Hit 1080 on my OG so I think I'm good.