Yorke (right) and Gaestadius (left) at a craft beer festival in Beijing in 2014. [Photo provided to China Daily]

After a few years of relying on a jerry-rigged system of buckets and a lot of experimentation, Arrow Factory's new site has the latest equipment. The beer is brewed on the ground floor and is drunk on the floor above, with seating for about 40 at the bar and tables, and a rooftop terrace with a view of willow-lined shores. It is ideal for group events and summer escapes.

The two business partners first met at a club in which Yorke was a DJ and Gaestadius was dancing in 2005. They are both keen on electronic music, something reflected in the occasional musical events staged in the two taprooms.

The new taproom was formally Yorke's own restaurant, Vineyard Cafe, near Liangmahe. He has another Vineyard Cafe, in Wudaoying, Dongcheng district, established in 2006, still a mainstay, and a popular restaurant on that old street.

Arrow's Mama Huhu Session IPA beer (40 yuan for 440ml) is a popular drink. (A Session IPA is one that has a low alcohol usually between 4 to 4.5 percent. IPA stands for India pale ale). Mama Huhu is low in alcoholic content, 4.3 percent ABV (alcohol by volume), hoppy and bitter but light and refreshing. Yorke says the Chinese name mama huhu (so-so) fits in nicely with the "anything but" feeling of this Session IPA.

Another best-selling drink is Seeing Double IPA. It is strong, bright and hoppy, with a real knockout of Citra and Simcoe, two popular hop varieties.

The duo brewers love to play around with hops. "I'm not a huge fan of using fruits in beer, though I think using pomelo or mango may be nice," Yorke says. "At the moment we are more focused on the hops. There is a huge amount of information about hops. Every hop has different oils."

But the pair say they eschew overly hoppy flavors. "Good beer just has good balance with nothing that stands out too much," Gaestadius says.

Hops is a critical ingredient in beer that can provide bittering and aroma, along with three other key ingredients of beer making: grain, water and yeast. Hop varieties are categorized as bittering, aroma, or dual purpose.

All of the many kinds of hops they use are imported, Yorke says. "I haven't heard about any great hops in China."

At the moment there is a dearth of hops due to bad crops in the US and last year in Germany, he says.

Apart from the 12 beers on tap, they have Oaked Sour Saison and English Brown Ale in the making, and they expect to have cider soon.