Mixing 2 yeasts to create house yeast

I am only a little of a year deep in the game of brewing. Recently I acquired a brand spanking new kegerator with 2 taps and have been harvesting yeast for a few months. I have French Saison (3711) and Belgian Witbier (3944) in rotation and I was thinking of combining them together and see what happens. I have been making a lot of wheat beers since they are easy, handle NYC summer temps and are easy to drink. 3944 brings out more orange citrus taste while 3711 is all grapefruit and I love the aftertaste sting of carbonation that it leaves. Its really bubbly and more clear than 3944.

What do you guys think will be the outcome of breeding 2 yeasts together. Should I go with more 3711 over 3944 in order to get more grapefruit taste that I prefer?

One yeast strain will dominate the fermentation. Mixing the two won't lead to an amalgam of their respective properties. There are a variety of microbiology techniques that you could attempt to employ in order to induce sexual reproduction of the two strains. While this would lead to a hybrid of the two strains, there is no convenient way by which to determine which properties of each strain will be dominant.

tl;dr Mixing two strains of yeast during primary fermentation will not blend their flavor profiles (or any other desirable characteristics).

If you want to combine the flavor profiles of two yeast strains, I think it's best to ferment two batches separately and combined them at kegging.

I was just thinking of combining both yeasts to a starter and letting sit for a few days before pitching it.

One of the yeast strains will thrive while the other one peters out. The health of each yeast strain and their ability to adapt to starter will be the dominate factors in deciding which one becomes dominant. Yeast, as it true of most fungi, reproduce primarily asexually. So there will be no mixing of the genetic material and consequently no fusion of the two strains.

You can read up on spore formation and the reproduction of fungi in a microbiology textbook to get an idea of how to create a hybrid yeast strain. The equipment and techniques necessary don't translate well to a kitchen "laboratory".

I'm pretty sure Wyeast uses blends of yeast to achieve certain flavor profiles. Wyeast 3056.

It's hard to say how your blend will work. One of the yeast may be more prevalent or they may come out balanced. It can't hurt to try.

Thanks guys!