When to brew a RIS

I want to brew an imperial, but I don't know how long it would take to mature. I am new to brewing and want to get a decent pipeline going that would last through an imperial before I start on that big dark beer

A good RIS is a big, high gravity beer. Fermentation on a beer like this can take quite a bit of time in the primary. Figure on at least one month to six weeks on the yeast cake followed by another month or two in the bottle/keg to condition and/or carbonate up. IMHO, the longer you let it condition, the better it will be. Many are aged a year or more and are constantly, albeit very slowly, maturing and developing.

That's what I figured for a minimum. I'll brew 1 or 2 more batches before I commit a fermenter that long.

Thanks

I brewed a RIS in August 2011. 84 days in the primary and then into bottles. It really came into prime late last fall. So in total it was about 15 months. I've still got some left and its still really good.

Ok let me ask here as well please. I'm about to make a Russian imperial stout from brewbrothers.biz....tonight actually. I was thinking maybe 3 weeks to a month primary then transfer to a secondary for atleast 4-6 weeks then bottle for maybe 3-4 weeks? Does this sound unreasonable?

Doesnt sound unreasonable at all, just make sure primary is completely done using gravity readings, not just gauging it by air lock activity. Fermentation can get stuck, and it will be easier to get it restarted (or wait for it to restart) on the yeast cake than it would be if you found out it wasnt done in secondary.

I brewed mine ris in July 2012, bottled in December and i will have few bottles but most of it i will drink next winter, so my advice brew one asap then store it for a year or so