First look: [...] as the sun starts to reappear, it’s obvious why the owners of Lokoya wines took a shine to their latest vineyard estate and first-ever stand-alone tasting room, which opened in November. Produced by winemaker Christopher Carpenter, the unfiltered, unfined wines could previously be sampled only at the family’s valley-level Cardinale Winery in Oakville; San Francisco’s Michael Mina and Quince are among the select few restaurants with an allocation. [...] visitors can taste Carpenter’s wares at the castle-like stone winery of the 77-acre Yverdon estate, hand-built in the 1970s and most recently the home of Terra Valentine wines. The tasting room includes large quatrefoil windows, walls of glass and a large deck, all with forest, grapevine and valley views — a suitably palatial setting to sample wines that command the princely sum of $375 a bottle.