I came upon Septime the old-fashioned way: by happening to stroll past one day, and noticing, in addition to the ambitious décor of the restaurant, a flyer advertising a public natural wine tasting, replete with some excellent names. (Cornelissen, Pfifferling, etc.) I wasn't able to make it to the tasting in the end, but I remembered the address when my friend / colleague D visited during men's fashion week, and she and I engaged in our quarterly trawl through Paris' culinary vanguard.*
Early reactions to Septime have run the gamut from impressed to enraptured. Chef Bertrand Grébaut has serious Michelin-star credentials, having worked in the kitchen at l'Arpège before running the kitchen at Agapé, when latter restaurant earned its star. ParisByMouth reports also that he received a 10,000€ grant from Evian-Badoit to open Septime, which budget, to judge by the cosy-industrial, Monocle-ready looks of the place, probably covered the cost of about seven light fixtures.
I don't mean to patronize. The place is indeed very enjoyably outfitted, with a nice wingspan around each table, and evident attention paid to lighting, ease of movement, etc. - the usual humane comforts that Paris restaurants, and natural wine spots in particular, have traditionally withheld as a method of torturing guests. And this mercy on Septime's part is, I think, just the most visible aspect of a wider change represented by Septime and restaurants like it: the maturation of the natural wine meal, mostly for the better.

