The French pharmacist Jean-Baptiste François (1792-1838) from Châlons-en-Champagne (until 1997 Châlons-sur-Marne) published a manuscript in 1837 in which he described a measuring method. This made it possible to determine the sugar content before the champagne was fermented in the bottle. This made it possible to precisely determine the "Liqueur de tirage" (tirage liqueur) during the dosage. This method became known as "Réduction François". Up to this point, at least 50% to in extreme cases even 80% of the bottles burst due to the excessive overpressure. The therefore extremely expensive champagne was only affordable for nobility and the wealthy.