In his era the in-bottle refermentation that gives sparkling wine its sparkle was an enormous problem for winemakers. When the weather cooled off in the autumn, refermentation would sometimes keep fermentable sugars from being converted to alcohol. If the wine was bottled in this state, it became a literal time bomb. When the weather warmed in the spring, dormant yeast roused themselves and began generating carbon dioxide that would at best push the cork out of the bottle, and at worst explode, starting a chain reaction. Nearby bottles, also under pressure, would break from the shock of the first breakage, and so on, which was a hazard to employees and to that year's production. Dom Pérignon thus tried to avoid refermentation.

In 1718, Canon Godinot published a set of wine making rules that were said to be established by Dom Pérignon. Among these rules was the detail that fine wine should only be made from Pinot Noir. Pérignon was not fond of white grapes because of their tendency to enter refermentation. Other rules that Godinot included was Pérignon's guidance to aggressively prune vines so that they grow no higher than three feet and produce a smaller crop. Harvest should be done in cool, damp conditions (such as early morning) with every precaution being taken to ensure that the grapes don't bruise or break. Rotten and overly large grapes were to be thrown out. Pérignon did not allow grapes to be trodden and favored the use of multiple presses to help minimize macerations of the juice and the skins.-Info from Wikepedia. Read More

Dom Pérignon was also an early advocate of winemaking using only natural process without the addition of foreign substances

Random Trivia: Pérignon spent a great of his career trying to get rid of the bubbles in Champagne.