Should I let Brett ride, or help it out?

So I'm looking for a little advice. While I was getting my stuff together last August for partial mashing, I figured I'd do one more extract kit. Looked around and Northern Brewers No. 1 caught my eye. Its a barleywine/old ale, OG ~1.1, ~65 IBUs. The recipe was fairly simple - 12lb of pale extract and 3lb of sugar - with the Wyeast 9097 special blend yeast (attenuative Sac. and Brett strain).

So I brewed it up, pitched a decanted 3L starter (only grew a few days, don't figure the Brett grew much), and let it sit. After 3 months I checked and it was getting a nice sized pellicle so I figured the Brett was taking hold. Well, a month ago (6 months in) I started to worry about it sitting on the yeast cake that long and was going to rack to a keg to keep aging. Checked the gravity and it was only down to 1.040 (about 60% attenuation). So, rather than rack to a keg I moved it to a 5 gal carboy, stirred up some of the yeast cake while racking, and planned on growing up a starter of some new Brett and pitching that to help bring the gravity down some more.

Fast forward to yesterday, Brett L (Whitelabs) starter has been growing for three days and figured I'd check on the beer. Now I'm starting to get another pellicle, real thin but a few bubbles on top.

So I'm going to the experts to figure out the best way to proceed. Should I leave the beer alone and hope the Brett can chew anther 5-10 points off, or should I go ahead and pitch the starter to help it along? I'm sure there's no damage to pitching the starter, but I could always use it for an all-Brett beer if people think the Brett already fermenting can get the work done

60% attenuation with over 25% coming from sugar (what kind?) and no crystal malts. Strange

Well, the big thing is what does it taste like and what do you want it to taste like?

Because if you don't want it too funky which I think is appropriate for an Old Ale then I would add a neutral yeast at high krausen.

You could add the Brett, but that depends on what flavor you want. Either way you could make another big starter and have enough for both beers. You don't need much Brett in secondary to get a big flavor contribution.

Yeah, I figured with the sugar (only 20% but still) it would have gotten down pretty far. Don't get me wrong, I definitely want it funky . Right now its starting to get some bretty flavors (sour cherry, little bit of barnyard), but is covered up by the residual sweetness. With the amount of extract I was hoping the Brett would have plenty of sugars left available that the Sac couldn't chew up, but I think there's still plenty of fermentable sugar left.

Over 25% of your gravity points were from sugar.
I think you would be better off adding both Brett and Sacc.

And one other thing I really like in Old Ales is a bit of Oak . About 1 oz will make it a bit more complex and up to 2 oz will make it a more dominant flavor. Plus the Oak gives the place for Brett to live and you can then use these cubes in future batches or give them to friends.

Ah, I see what you're saying, my bad. I'd considered oaking it, but didn't want to take on too many new twists. Was my first foray into brett so figured I'd try to keep it simple (says the guy with the 1.1 OG ). Maybe I'll let the brett that's in there hang out for a few more weeks and toss a higher grav sach strain on there. Now I've gotta come up with a good Brett L recipe! Thanks!

12 lbs of LME ( I'm assuming it was LME, and not DME) + 3 lbs of sugar in 5 gallons will give you and SG of 1.114. Note: If it was DME you would have had an OG of 1.135.

Got down to 1.040; that's about 65%. Somehow seems low. What temperature is the wort at? I would expect that yeast to get you lower, but I'm not sure you could expect much better than 1.030 (74%). Leave the Brett to do it's work. With that gravity and alcohol, I'm not sure adding anything more is going to do much for you.

If you used DME, then I would say you defenatly done, and leave it alone.

Yeah, it was LME. It was actually probably a little closer to 5.25-5.5 gal, since I always aim a little higher to wind up with 5 gal in the end. For the first two weeks it fermented in my swamp cooler with ice bottles, and after two weeks I stopped adding ice bottles and let it warm to ambient (about 68 degrees). After another month, I pulled it out of the swamp cooler and just let it hang out at ambient temp.

Definitely with this much extract I'd be happy with 1.030 . It was still a little sweet when I tasted my ~6 month hydrometer sample, but some of that could be the alcohol still melding. If it had stopped higher than 1.040 I probably wouldn't even bother with Brett, but since I was pretty close anyways I was hoping the Brett could pull it down a few more points.