This is the third year Moortgat has run this project. The first batch used 100 Kentucky Bourbon barrels, said Duvel UK marketing manager Natalya Watson, while the second had 190 and the latest was put into 351 barrels last year. She wasn’t sure if they were new barrels every year, but from reading Duvel's website I think they re-use them after re-impregnating with fresh Bourbon.
They now have barrels from six different distilleries, including Four Roses, Buffalo Trace, Heaven Hill, Jack Daniels and so on. This highlights the challenge of acquiring used barrels in bulk, which is why I reckon they're being re-used. The aged beer was all blended together for consistency before bottling, Natalya said. Bourbon barrels are 200 litres or 53 US gallons, and each yielded enough to fill around 240 75cl bottles – I suppose the 10% disparity must be leakage and other ‘process losses’.
The result is an amber-brown beer that almost glows in the glass and has aromas of sweet vanilla Bourbon, quite unlike the yellow of Duvel itself, with its lemony spicy-hoppy nose. The barrel-aged version is rather sweeter too and warming, with more vanilla and an unexpected faint salty note in the finish.
Natalya also introduced those of us who’d not met it before to Duvel on Tap. This is not a draught version of bottle-conditioned Duvel, but the same beer put into kegs and keg-conditioned (yes – if it weren’t for the carbonation that would make it real ale). She explained that the distinction is important because Belgian brewers typically adjust their recipes for kegging, in particular lowering the carbonation to avoid fobbing (excessive froth).
Duvel’s brewers didn’t want to do that, so instead they came up with a new dispense system for their branded fonts. The problem was that it’s a remarkably gassy beer – its CO2 content is twice that of standard keg beers and three times that of many craft beers. The solution involved two metres of 3mm piping (far narrower than usual, and non-reusable as it’s too fine to clean) to ‘break’ the pressure in the keg, plus anti-fobbing training for the barstaff.
Mind you, despite being the same 8.5% brew as the bottled Duvel (and Duvel Tripel Hop) we’d been drinking earlier, it didn’t seem as complex. The hops were still there, but not the lemony-spicy note – I wonder why, if they’d got everything else pretty much the same? Still, a lovely beer and one to watch out for.
My thanks once more to Duvel for supplying free beers and arranging the tasting, and my apologies again for how long it's been since I last posted here. Life keeps getting in the way...