While the rest of Brussels is still tucked under the covers on Saturday morning on November 15, 2025, a quiet crowd gathers on a nondescript street in Anderlecht. Here lies a building that can be considered a beer cathedral to time. Today is Brasserie Cantillon’s public brew day, a rare moment when the curtain is pulled back on a historic brewing process. Here, there are no lab-grown yeasts or computer-controlled tanks. Instead, the Van Roy family is preparing to “catch the wind”—opening the attic shutters to invite the wild spirits of the city air into their beer, just as they have for 86 years. Cantillon, founded in 1900, is the last traditional lambic brewery in the city. When the older brother of Jean van Roy’s great grandfather, Paul Cantillon, inherited the family brewery, Paul started the Cantillon blendery. Only in 1939 did he start producing lambic. Since then the rest of the brewing world moved toward stainless steel, isolated yeast strains, and rapid production, Cantillon has kept its old ways of working alive.
As I enter the heavy wooden doors of Brasserie Cantillon, I’m greeted by a swirling barrel being cleaned. I am late due to my train from Rotterdam having been canceled, but in true Belgian style (and thanks to tour guide Carien) I am generously added to the next Dutch language tour starting in the next 30 minutes. While waiting I use my ticket for the – traditionally post tour – tastings in the little bar by the entrance. On public brew days you will encounter the whole Van Roy family helping out.
Cantillon brewhouse
The public brew day starts significantly earlier than a typical museum visit, usually at 6:30 a.m., to accommodate the long brewing cycle required for spontaneous fermentation. My tour starts after 11 a.m. when the filtration is in process and the mash tun has been emptied. For a 10.000 liter brew the grain bill is made up of 850 kg barley and 450 kg unmalted wheat. What is left is a light brown-colored goo, thick and pasty.
Next, our tour guide Flosh takes us upstairs to see the two boiling kettles bubbling away. One kettle has spit out some of the hop, as if it didn’t like the taste of it. Cantillon uses massive amounts of hops, but they are aged for three years until they lose their bitterness. They aren’t used for flavor; they act as a natural preservative to keep “bad” bacteria at bay during the long aging process. Jean van Roy is there looking on, perhaps willing his stern look to keep the kettles in check. Most of the brewing equipment was purchased secondhand and is over 100 years old.
A small narrow staircase leads to the attic where the bags of malt are kept. If you look closely you can see light coming through holes in the roof in several places. Next to this large space there is a smaller room housing what for many is the highlight of the tour: Cantillon’s copper coolship. It can hold 7.500 liters and the cooling process takes around 16 to 18 hours. This explains why the roof is not insolated, though with heavy rain I wonder how they keep everything dry up there. Not visible from the inside are the 96 solar panels on the roof that produce all the electricity used in the brewery. According to their social media post three days prior, the nights were still a little warm for brewing. It needs to be cold enough for bacteria not to be active, but not too cold as to deactivate important yeasts. During our tour the coolship was empty, so I went back afterwards (with the brewer’s permission) to take a peek of it after filling. What a beautiful sight! It is a very large, shallow, rectangular vat made entirely of copper. The use of copper is traditional because it is an excellent conductor of heat, allowing the boiling wort to cool rapidly. The shallow depth is designed to maximize the surface area of the liquid. This is critical for the “spontaneous fermentation” process, as it allows the wort to be exposed to the wild yeasts and bacteria present in the Brussels air. The coolship is a primary reason why lambic brewing is seasonal. It is typically only used during the colder months (usually November to April) to ensure the wort cools to the correct temperature within a single night.
The barrel room
We make our way back to the boiling room and into one of the barrel rooms, a large adjoining space filled with about 400 dusty and cobweb covered barrels. The letters on the barrels indicate what beer is in them, in what season it was made and which batch of that season. You can probably guess what the “L” stands for, but aren’t all their base beers a lambic? In fact, Cantillon makes one all malt and dry-hopped beer called Iris. Letter “A” on the left signifies season 2023/2024 (we are now in season “C”) and the number on the right is batch 6 of that season.
The end of the barrel room held a very special surprise tasting. To celebrate their 125th anniversary (1900–2025), Brasserie Cantillon brewed a special commemorative beer named simply Geuze 125 that deviates from their traditional lambic recipe. While a standard Cantillon lambic typically uses approximately 35% unmalted wheat and 65% malted barley, this anniversary brew features a 50% wheat grist, based on Jean van Roy grandfather’s recipe and is Florian (Jean’s son) very first beer as a brewer. By increasing the raw wheat content to 50%, the beer gains a more pronounced “breadiness” and a fuller, softer mouthfeel compared to the sharper, more vinous character of their standard gueuze. Personally I found it to also to be very ‘lively’ and have greener flavors, as if it had more hop bitterness (but that was probably my imagination). It’s an 18 month old lambic brewed in 2017, aged in a single barrel for 4 years, and bottled in 2021.
For a more technical account of the brewing process and public brew day, check out Chuck Cook’s article.
The upstairs bar
A visit to Cantillon is not complete without a visit to the upstairs bar, where you can buy some of their best beers by the glass or by the bottle. The bar is much more than a simple taproom; it is a rustic, living museum where beer enthusiasts often gather to share rare bottles. Among the old brick walls and mementos, longtime bartender Berto is a permanent fixture and familiar face.
All photos by Tina Rogers, unless otherwise specified.
