Oude Geuze Remy Le Mercier
Description
A limited edition geuze made from 60% malted barley, 30% malted wheat, and 10% oats, released during Kelderdagen (Cellar Days) on 17-19 October 2025.
The beer is named after Remy Le Mercier, who in 1559 held the office of receveur communal de Halle (a municipal receiver), and authored an ordinance that includes what is now seen by some as the oldest known recipe connected to lambic in that region.
5,400 bottles were produced at 8% ABV.
Side Notes / History
The beer is based on an old 1559 recipe from the National Royal Archives in Brussels by Remy Le Mercier, regarded as some as what could be the oldest known lambic recipe (as we now know, the origins of lambic are a vivid debate among historians of the scene).
In the following text, the Boon brewery describe the beer as well as the origins behind it in detail :
"Our passion for tradition does not stop at beer itself: from time to time, we delve into history in search of forgotten knowledge. Recently, we were reminded once again of a special document from the National Archives in Brussels: an ordinance from 1559, prepared by Remy Le Mercier, mayor of Halle. A piece that will undoubtedly stir up a bit of dust among experts.
The text lists the correct grain ratios for local beers of that era, such as keut and houppe. Today, the document is considered the oldest known recipe related to lambic—due to its typical composition and location.
What immediately stands out? The mention of oats. A variety of grain that is rarely found in lambic today, but is still legally permitted in addition to the required 60% barley malt and 30% wheat.
Precursor to lambic
Oats, then. There is no doubt that beer recipes evolve over time. Technology changes and legislation also has an impact. And yet, the grain ratio used by Le Mercier is remarkably close to what is standard today.
We put it to the test
Thanks to Remy Le Mercier, we know that lambic has been brewed since at least the 16th century. So we used his recipe as a guide for an exclusive Oude Geuze.
On February 22, 2024, we filled no fewer than 5,400 75 cl bottles. Because oats contain more fiber than barley, it took a little longer for the lambic to clear, but that was only a matter of time. With this Oude Geuze Remy Le Mercier, we prove that oats can indeed play a role in the production of Oude Geuze.
The result: a smooth, full-bodied Oude Geuze with a firm head and a clearly recognizable nutty flavor from the oats."