I BROKE into a loopy grin as a research scientist-turned-brewer slowly stirred the massive kettle of Munich, crystal and roasted malt, gently cooking it at precisely 154 degrees.

In about three weeks, this 300-gallon batch at Seattle’s Schooner Exact brewery will become Brave Horse IPA. I’ll greet it with love.

I’m not alone. About a quarter of the Seattle beer market is craft beer, quadruple the national percentage. It’s harder to find a Bud Light on tap here than it is a funky small-batch sour beer or a bourbon-barrel aged stout.

It is a homegrown beer mecca. But this artisan industry suddenly feels fragile.

Last week, Gov. Jay Inslee proposed extending and making permanent an expiring $23.58-a-barrel beer tax to fund education. That tax now just applies to mass-produced beers. His plan would, for the first time, also extend it to microbrewers, who currently pay $4.78 per barrel.

Raising $127 million for kids is laudable. But how many fewer Brave Horse IPAs would be drunk if pints cost 50 cents more?

“The tax would just crush some brewers,” said Kendall Jones of Washington Beer Blog. Competition with Oregon, which was a $2.60-a-barrel tax, is fierce, and the cash flow of many brewers is too tight to absorb a steep upfront tax.

Washington has been beer-rich since homebrewers emerged from their basements with business plans in the 1980s. But Seattle is in a new age of brewing, Jones said, because 40-somethings like me grew up with choices other than Rainier’s Vitamin R.

Almost any night of the week, Chuck’s Hop Shop on Crown Hill is packed. Parents sip from 20-some exotic tap beers. Their kids eat ice cream. There’s a food truck outside. It’s beer-vana.

Most local brewers feeding those taps literally run mom-and-pop businesses, like Schooner Exact founders Matt and Heather McClung. They quit their teaching jobs just a few years ago, and produced about 85,000 gallons of beer in 2012.

Local brewers are friendly, said Heather. “It’s like, make good beer, convert the masses, and everyone shares in the pie.”

I asked Heather if she’d move brewing operations to Portland, as Redhook has suggested. She paused, and said she hadn’t thought about it before. But I could see wheels turning.

— Jonathan Martin