The conference at Domaine Willamette attracted several hundred people for a day of learning about, discussing and sampling sparkling wines. Winemakers from 22 local wineries such as Corollary, Ponzi and Argyle — the latter a pioneer in Oregon sparkling wine production — poured bubbles at a luncheon and an afternoon wine tasting event. One thing was clear: although making traditional sparkling wine is time consuming and results in higher-priced bottles, conference speakers and attendees alike say it is worthwhile. He discovered sparkling wine is “a challenge … that takes technical expertise.”It also takes a lot of specialized equipment. Radiant Sparking Wine Company now handles some of the traditional processing for about half the state’s sparkling wine producers.