Monday 2 October 2017

A visit to Rodenbach brewery

Day two of the IBD study tour kicked off with a visit to Rodenbach brewery. This was the one I'd really been looking forward to. Like porter brewers of old they still have masses of oak vats they mature beer in for two years.

We got to see the vats, lots of vats: 294 in total. But we didn't get to see the new brewhouse, which is a shame. They have a Muera mash filter and brew four to 12 brews a day, with a brewlength of 250hl. 17% maize is used in the grist, the malts being Pilsner, Munich, Vienna and cara. The grist is hammer milled in a wet mill. The mash kettle starts at 53°C for the malt, and the maize first goes into a  cereal cooker at 90°C. When the maize is added to the mash the temperature rises to 63°C and it is then stepped up to 73°C and finally 78°C for mashing out. Hops are added to 10 IBU (mainly for foam stability) at the start of the one hour boil.

In the Fermentation Vessels (750hl of wort in 1000hl cylindroconical FVs) yeast and lactic acid bacteria are added and fermentation is carried out at 21°C for four days before chilling. The beer then goes to horizontal maturation vessels for five weeks at 15°C.

Young beer can be sent to vats for maturation or used for blending.

They used their own maltings until 1975 and we had a look round that.

As well as seeing the old brewery. 

Then it was on to the vats:

It was like being in a Barnard drawing (though the Rodenbach vats are covered):

Thanks to Geoff Latham for the picture

The vats range from 120 to 650hl in size and they have over 12 million litres in maturation. The vats are steamed lightly after two years as the want to preserve the microflora (Brettanomyces and Pediococcus). Old beer is also mixed with young beer on each fill.

When vats are ready for blending after two years ten vats are blended at a time. Gas chromatography is used to measure fruity esters (ethyl lactate and ethyl acetate), and the taste is also assessed. Classic Rodenbach has 1/4 aged beer, Grand Cru 2/3 and Vintage is 100% aged. Some beers have fruit added (sour cherries, cranberries and raspberries) for six months after the beer has matured for two years.

The trip ended, as it should, with a tasting.

 Though it's not to everyone's taste I am rather fond of the Grand Cru so I did well at this tasting. 

Thanks to Richard Rees for the pictures of Rodenbach


  1. Nice report. Was porter as sour though...?


    1. I don't think so as the higher hopping rate would have stopped lactic acid bacteria growing.