I used to make a Christmas stout (Russian Imperial Stout) that I would brew in December and then age until the next year and give out for the next Christmas to a select group of friends. I am going to make it this year, but am thinking about adding some other factors. I was using Molasses to push up the gravity but, thinking of the English root of this style I'm considering Treacle. Also, It will sit in primary for probably two weeks or so, then secondary for a month. In secondary I plant to add wood chips. I'll then use a tertiary fermentation with a split batch. One half will be without Brett and the other half with Brett. The question I have is what strain do I use for the Brett? I am considering Clausensii, but am wondering if someone could give recommendations and considerations for this. I may also add some sourmash to the boil, but am not sure if it would simply be overpowered by the brett.