50% Mondeuse/50% Altesse + Chardonnay. Though not vintage-dated, Peillot's Brut is always single-vintage, methode champenoise wine. Most cru Montagnieu sparkling is Chardonnay-dominant; Peillot emphasizes local varieties Altesse & Mondeuse. Average vine age is around 30 years, with some plots of Altesse and Mondeuse up to 60 years old, planted mainly on rocky limestone scree on a steep slope right by the village of Montagnieu. The farming is organic. The bunches are harvested by hand and vinified separately by variety and parcel. The clusters are direct-pressed and spontaneously fermented in tank; the blending takes place in late winter. The blended wine is bottled with a liqueur di tirage and finishes fermentation in the bottle; it is disgorged and finished with a 6-gram dosage. Bugey is the AOC and Montagnieu is the village and cru.