Monday 13 November 2017

A visit to Westmalle brewery

I've read an awful lot of brewing text books and technical articles. I've also been to an awful lot of breweries. And I have to say the way things are done in breweries rarely matches with how things are written in text books. There are inevitably compromises that have to be made in production to ensure that beer can be made in the amounts needed and with the staff available. But not at Westmalle. The Trappist monks that have overall control of the brewery clearly don't skimp on investment and there was mightily impressed equipment, and an equally impressive commitment to quality from the staff.

The new brewhouse was shiny and automated:

They have a brew length of 200hl and brew four times a day, Monday to Thursday. They use three types of malt and six varieties of whole hops with some CO2 extract for bittering. An interesting point was made that it's easier to assess whole hops for disease compared to pellets. About 10% sugar is used and three hop additions are made during the boil. Three beers are made: Dubbel, Tripel, and Extra at 4.8% which is made for the monks. Triple now accounts for 70% of the 130,000hl produced annually. 

The brewhouse has an MCV and lauter tun. They also have an energy storage tank and a pre-run vessel and the wort is heated to 97°C before entering one of the two copper. Evaporation is 7%. As they use whole hops they also have a hopback.

The old brewhouse was also shiny but less automated:

The wort is aerated to saturation and the 400hl cyclindro-conical fermentation vessels are not too high so ester formation is not inhibited. The beer ferments down to 1004 and it is increased by sugar addition to 1008.5 on bottling. The beer is slowly clarified in 800hl maturation tanks: five weeks in vertical tanks or three weeks in horizontals. After maturation the beer is centrifuged and then re-seeded with the same strain of top cropping yeast.

We got to drink some beer from the FV which I have to say was rather good.

We were also offered the chance to have a drink of the yeast. I declined though others were braver:

Note this is George drinking the yeast, not the beer
 The bottling line dates from 2007 and runs at 45,000 bottles per hour.

The carbonation is 4g/l on bottling, which rises to 8.5g/l after 18-21 days of conditioning at 22°C in a warehouse where 50% humidity is maintained.

There was beer and cheese laid on after the tour:

So I had to try the Extra:

And the dubble. Oh yeah, and more of the tripel too.

Thanks to Richard Rees and Toni Ryman for the pictures


  1. Looks a lot like the presentations online of them and other trappist breweries.

    "After maturation the beer is centrifuged and then re-seeded with the same strain of top cropping yeast."

    A lot of people will be glad to hear that.

  2. > ... in a warehouse where 50% humidity is maintained
    Any idea why they consider that important? Surely the beer is completely isolated from the humidity outside the bottle.

    1. That's a good point, you've got me thinking now. I'm afraid I didn't ask why at the time though.