How long can post mash wort sit before boil

[Jbrew]

Tried searching this, seems overnight really isnt a big deal. However, my situation is as follows:
Started brew day Friday afternoon, mashed in, got low efficiency, (but that's another topic), and then ended up having to go out for dinner (unplanned). By the time I got home, was just too late and unmotivated to start the boil as it would have taken about at least another couple hours to complete, which would have put me close to midnight and i had work early next day. Decided to let it sit figuring I could boil it next day which was Saturday after work. Well work ended up running late Saturday, and found out i have to work late all day Sunday which is today. So now my next available time to complete this brew will be Monday around noon time.
So the wort will be having sat for approximately 72 hours. Is it safe to continue?
Should I just toss it? It was a mesquite wheat kit from my lhbs for about $23 and i still have the hops and yeast, so I really only lost about $15 grain if I have to toss it.
What's everyone's thoughts?
Its currently sitting in my BK, at full pre boil volume at approximately room temp of about 65 degrees.
Can botulism grow in these conditions or is there anything else that could have gotten into it?

 

[dmtaylor]

The boil will kill anything that got into it. You can't get botulism in just one day, it takes months. I would go ahead and use it, but try not to do this again. You might have lost a few gravity points to wild yeast -- probably not but it is certainly a possibility. Even so, just brew it today right away and I'm sure it will be fine. One thing that probably will happen is that the enzymes could continue to work all this time, which will result in a very dry beer. If this happens and you don't want it so dry, then add a half pound of lactose or something like that after fermentation is complete to bring the body and gravity back up again.

 

[Mike_kever_kombi]

Unless you mashed out you probably had a little bit more residual conversion. You most likely will also have a sour tang (and be a little thin) to the finished product.

I once left mash in pot for 25 hours just to see what would happen. It was only about 2 gallons of mash, but the above stated is what resulted.

For me, and for $15, I would just start over. If you decide to press on, a 60 minute rolling boil will kill off any nasties.

 

[Jbrew]

I actually did do a mash out. Im going to try and see if I can get any time tonight to try and finish it.