Leaving in primary

So I'll be leaving for a training mission for 3-4 weeks. I'll leave on a Monday and will be bottling what I have in my fermenter the day before. This will ensure my first batch will condition for at least that long. (honestly ill be tapping Ito it as soon as I get back). What I'd like to do is as soon as I get my first batch into the bottles I'd like to cook up a new batch and get it fermenting while I'm gone. This will make sure I have a new batch ready to go into bottles when I get back thus eliminating any possible long lag time between my first and second brews. Will this cause a problem leaving a batch in the primary for that long? I'll have to hook up a blow off tube to make sure there's no overflow from the airlock. I wouldn't be around to clean it up and the wife wouldn't be willing to take on those kinds of duties. Does anyone foresee any problems with this plan.

The main problem I foresee would be the blow off tube being overloaded, and still ending up with a sticky mess on the floor (or worse, the tube clogs and your lid/stopper goes ka-boom all over the place). Assuming that won't happen because you have a container with adequate headspace, good size blow off tube, and the beer doesn't go wild and crazy, you should be fine. 3-4 weeks is nothing out of the ordinary to let a beer sit in primary, really.

I frequently leave beers in the primary (rarely use a secondary) for 3-6 weeks with no problems whatsoever... Only advice would be to try to ensure the proper temperature range for the yeast/beer. Good luck....

From what I've learned from the great folks on this forum it should be fine. My first two batches sat for three weeks and I couldn't bottle my most recent batch due to some things that came up so it sat for four and I asked the same question as you. Everyone said it should be fine if not better. So let it ride then three weeks in the bottles and it should be good to go.

The longest fermentation I have done was for an 80 Schilling Scotch Ale that was in primary for a month and then went into secondary with oak chips for two months. It came out fantastic

It will be fine! I schedule my brew days around vacations and trips so I can get away and forget about it. Personally, I let my beer go 3 weeks or more. I don't need to, but I've built a big enough pipeline and I like to give the yeast plenty of time to do everything it needs to do! Train away and come back and relax!

I think it will actually be better with longer primary. If temp control is fairly steady, no worries in my experience.

Good stuff. Thanks for the tips guys. Glad that this is a feasible idea.