How long do Brussels sprouts on the stalk stay fresh?

Depends how they are stored. In the refrigerator, they could keep for weeks.

Really. That's good to know. Originally I wasn't going to use them tonight as planned, but I may use one branch and save the other if they'll keep well. Thanks!

Those branches took some TIME! But I think it'll be well worth it

Next question: Blanch or no blanch? They're pretty small except for one or two, which I can cut. Going to be sauteeing them in bacon fat (and bacon).

Update: Sprouts were very good! Ended up having my original plan overruled in favor of doing a bacon preparation Jenn had at one point, but I got mine back by throwing in some white Balsamic vinegar (which was more or less how I was going to do them initially but without the bacon. On the other hand, what's not good with bacon?) for a light glaze. Between these and the sprouts we had at the Corduroy dinner with the venison, I don't see what the big anti-Brussel's sprout deal is!

ScotteeM: I did end up blanching them, if only to speed cooking time because I fell behind a little slash the meat finished faster than I expected and I ran out of time. These were small enough (except for a few) that it probably wouldn't have been otherwise nessesary.

I usually don't blanch before sauteeing in bacon/drippings, but I do usually quarter them lengthwise.

That's some good eating!