Yeast & Fermentation

The Vermont IPA is top-fermented. The yeast works at temperatures around 18 to 22°C, noticeably warmer than for a lager, and rises to the top of the fermenter as it works. This happens quickly, with primary fermentation wrapping up within a few days. Warm-fermented yeast releases fruity byproducts called esters, and these esters complement the hop aroma.

The most famous strain is called Conan. It traces back to the yeast Greg Noonan used for the Vermont Pub & Brewery in 1988, labeled VPB1188 in the lab. It's said to have earned its nickname for its forceful, vigorous fermentation. It's generally considered to be of English origin, possibly connected to the Boddingtons brewery, though this has never been confirmed.

According to the brewery, Heady Topper is fermented with this strain. Conan consumes a lot of sugar, which leaves the beer dry, and it emphasizes peach and orange notes. Later, the strain spread among brewers across New England. Homebrewers today can buy it as liquid yeast to recreate the flavor of these beers.

What happens afterward is important too: the beer isn't filtered and isn't aged for long. Yeast and hop residue remain suspended as fine particles in the beer, creating the haze that gives the style its name. It's kept cold, but not for months like a lager, and the fermentation cellar in Waterbury or Stowe is more of a hall with stainless steel tanks than a rock cellar. Canning usually follows quickly, since the aroma peaks in the first few weeks.