I took a stab at this a few years ago. It came out really good, but I wasn't quite there. I used a 50/50
blend of WLP005 & WLP500. My thoughts at the time is that it just needed a little more bitterness and that little lemony thing I get from Taras Boulba.
The hardness of Brussels water is obvious in TB -
Molenbeek uses Boitsfort and Callois water, punch Molenbeek-Saint-Jean into the widget at the bottom of
this page and you'll get an analysis that looks something
like this - 130ppm Ca, 350ppm HCO3, 70ppm SO4, 35ppm Cl
Obviously we don't know the extent to which they are Burtonising, but terroir seems quite important to them so I wouldn't imagine they're doing much beyond possibly a bit of gypsum.
Ed Wray has lots of detail on their process - they mash at 45-62-72-78°C with different times for different beers. Hop pellets rather than cones, 95% of the hops used are German or Slovenian.
Yvan : "Tettnanger and Saaz stand for the bulk, and beyond them, we primarily use Savinjski Golding and Hallertau Hersbrucker".
10-15% crystal sugar is added to the copper for beers over 6.5% ABV, liquid invert sugar is used to prime secondary fermentation in keg (?!) and bottle. "Carbonation of 5.5g/l is aimed for in bottles". Collect wort at 21-22°C; weak beers are allowed up to 26°C to encourage esters, strong beers up to 24°C to minimise fusels. 5-6 days in fermenter and 14-15 days in secondary at 23°C - part of the idea is to free up space in the primary fermenters which are filled to 1m or 2m and are the limiting factor but which they deliberately use to avoid the hydrostatic pressures of tall thin conicals. Brett beers get 3 months at 15°C.
This has more on their yeast harvesting.
Coy on their house production strain other than it's a single strain of Saccharomyces from a big-name Belgian brewery, they reuse it 30-35 times before re-propagating. It's obviously POF+, which would rule out Rochefort and de Koninck, and implication would be that it's not a dry strain. Their Brett-B strain is a wild one from a local homebrewer.
Reading
this (which also explains the origin of the name) :
It is a modest 4.5% in strength, revealing one of its sources of inspiration. “If I have one beer style that is my favorite ever,” De Baets says, “it’s a good English bitter properly served from the cask. Taras could be seen as a Belgian version of that.” That’s certainly a cask-like strength, far lower than most Belgian offerings. Okay, what else? “We are also big fans of traditional German pilsners,” he continues. “We see [them] as a sort of achievement for a brewer to make. Hence the noble hop character of Taras....
It has a wholly unique flavor: a bright lemon stiffened by minerally hard water up front, then a slow evolution into a dry herbal finish....The beer may be hop-heavy (in addition to bittering additions, Senne dry-hops Taras Boulba)....“It’s a yeast we’ve chosen carefully for the subtle, mellow esters it gives. We enhance them using very flat fermenters we designed ourselves.” He points out that the bitterness comes from the hops, not phenolics, but I’d emphasize all the heavy lifting the yeast does in other ways. Esters up front accent the lemony hopping and create the spritz that buoys this beer. In Taras Boulba, the way those esters work with the bitterness, the way their aromas harmonize with the citrusy hops, are what tie the beer together.
The emphasis on subtle esters rather than phenolics makes me think of witbier yeasts. Combine witbier with the pride they take in being from Brussels and I think of Blanche de Bruxelles - I'd suggest the Lefebvre yeast must be a favourite? So I'd be thinking 3944 or WLP400, maybe Brewferm Blanche as a dry yeast?
I've only had Taras once, towards the end of a beer festival so my memory is a bit hazy other than it was nice!