The thing to keep in mind with WLP670 is that it is a blend of sacchromyces and brettanomyces. So, the initial primary ferment will be fairly clean, earthy, malty, and spicy from my experience. Brett. is a slow fermentor and starts to kick in later. After 2 weeks most of the yeast character is the saison strain from my experience, with a "clean" Brett. charachter in the background. If allowed to continue, the Brett. will continue eating all of the fermentables and dry the beer out. I have used this strain twice. The first time was a lambic project with some other club members using a turbid mash. I used the WLP670 strain while others used the traditional lambic fermentation. I have a nice pellicle on my glass carboy after a seeming normal yeast ferment 9+ months ago. The second time, I made a farmhouse pale ale and racked to the keg and chilled after about 3 weeks. Fairly clean ferment character. I fermented in my basement in the mid to high 60's both times.
As far as recipe and mash formulation, I would think you can avoid any simple sugars. The Brett. will take the gravity down pretty close to 1.000. You do want some dextrins in the beer: oats, rye, spelt, wheat, etc. (See the AHA recipe from Chad Yakobson). I would also mash a little warmer than your typical saison if you are wanting to emphasize the Brett. character, 152-156F. When you stress Brett. that is where you get the funky flavors. Also, use some acidulated malt in the mash. Brett. likes the environment a little more acidic than Sacchromyces. Anywhere from 1-5%. If you want to keep the Brett. character to a minimum, just throw it in the fridge in a keg after the Saison yeast has done it's job. The longer Brett. goes, the funkier it gets.
Brett. is a yeast just like Sacchromyces and can be killed just as easy. The spores can sometimes be a problem. Glass and stainless steel are of no concerns and can be cleaned and santitized as you normally do. I would keep all of the plastic and rubber stuff seperate, however.
There are a couple other topics on the forum in regards to WLP670. Good Luck! Let us know how it goes!http://www.homebrewersassociation.org/forum/index.php?topic=8863.msg109812#msg109812http://www.homebrewersassociation.org/forum/index.php?topic=7415.0http://www.homebrewersassociation.org/forum/index.php?topic=11034.msg149146#msg149146