using different yeasts

so i was going to attempt my first high gravity beer, and i heard its a good idea to pitch more yeast when you move to the secondary. its a belgian dark strong ale (1.091 OG) so i was thinking of starting with WYeast 1388 and then culturing some delirium nocturnum yeast for the secondary. my question was which yeast would contribute most to the flavor, and is adding a third dose of yeast for bottling really necessary? also, would it be a better idea to stay consistent with which strain i use?

If you want to blend yeasts, do it from the start. Even though it's high gravity, with proper pitch rate it won't take an appreciably longer time then most other beers to accomplish most of it's fermentation. I'd stick with one yeast throughout though, but that's just me. I like having _some_ degree of repeatability in my beer. Ss for bottling, just make sure you rack a little bit of your yeast cake into your bottling bucket. Don't primary at all either, just let it sit on the yeast, let the yeast work.

I think El_E meant to say don't secondary.

Just use a single yeast. The flavor would come from the initial yeast anyway. A second yeast would only help with attenuation, and that's if it was a more attenuative yeast.

Planning to use a second yeast is not an easy thing. I've only done it when I wanted the flavor profile of the first yeast and knew it didn't attenuate as much as I would like. Since the beer has a lot of alcohol and not a lot of fermentables, the second pitched yeast will not reproduce, so you really need to pitch a lot of yeast while it is working; that is, make a starter.

No need to add any extra yeast at bottling either, unless you are planning on bulk conditioning for a year before bottling.