Changes

Meerts was traditionally a product from the later runnings of the mash. As the extractable sugar levels decrease with continued rinsing of the grains during the sparging process, subsequent mash runnings have progressing lower original gravities (lower levels of sugars for fermentation). The sugar-rich early runnings of the mash would be used for producing lambic, leaving the later runnings for Meerts. These two different worts would then be boiled separately.

References to a beer called "Naar goed", made from the later runnings of a lambic mash, can be found at least as far back as the 1820s<ref name = 'Bataafsch Genootsap'>Nieuwe Verhandelingen van het Bataafsch Genootschap der Proefondervindelijke Wijsbegeerte te Rotterdam. Zevende Deel. 1829 </ref>. By the mid 1800s, this final runnings beer is referred to as "Bière de Mars" in French-language brewing texts. Bière de Mars had an original gravity around 5 P<ref name = 'Lacambre 1851'>Lacambre. Traite Complet de le Fabrication des Bières et de la Distillation des Grains, Pommes de Terre, Vins, Betteraves, Mélasses, etc. Tome Premier. 1851 </ref>, or about 1.020, and a final alcohol percentage around 2-2.5% ABV.