Larmandier-Bernier is one of Champagne's top grower-producers. The Longitude is a step up from their entry level Latitude and I reckon it's worth the extra $20.
This is 2017 base with between 35 and 40% reserve wines going back to 2004. Like the Latitude, this is 100% Côte des Blancs chardonnay, yet the vineyards from which it was drawn have thinner topsoils and so the vine roots plunge straight into the chalky bedrock. The name here refers to the vertical nature of the geographic locations of the vineyards as well as the style that results from the very chalky soils of these sites—a more linear, mineral wine. The vineyards are located in Cramant, Avize, Oger, and Vertus (north of the village). While Larmandier’s Latitude is more expansive across the palate, the Longitude, whilst also being ample enough, is a showcase of minerality, line and raciness.
"This is simply a superb Blanc de Blancs, and a prestige cuvée by any other name. It is a terrific food wine—match it with anything that you might pair with a Chablis, Riesling or any white from the Loire."
“Another lovely wine from Larmandier-Bernier, the 2017-base NV Extra-Brut Blanc de Blancs Premier Cru Longitude was disgorged in April 2020 with three grams per liter dosage. Mingling aromas of citrus oil, green apple and pear with hints of white flowers and fresh bread, it's medium to full-bodied, elegantly enveloping and precise, with a more mineral, chiseled profile than the Latitude bottling, reflecting its origins in optimally situated parcels in Vertus, Oger, Avize, Cramant. As I've written before, this is one of the finest non-vintage bottlings to be found in Champagne, and it comes warmly recommended.”
93 points, William Kelley, The Wine Advocate.