The Peillots might be better known for their excellent still wines, but this 50% Mondeuse, 50% Altesse/Chardonnay is an absolute delight, as well as being a superb value. There's a limestony-mineral freshness that's very assuredly Alpine, and the use of Mondeuse (most sparkling Bugey is Chardonnay) offers interest, depth and complexity. Sustainable viticulture.