Home Cover Behind The Beer: Vault Brewing Offers Taste Of Hawaii With Haupia Pie-Inspired...

Behind The Beer: Vault Brewing Offers Taste Of Hawaii With Haupia Pie-Inspired Beer

It might be pumpkin beer season but one small Pennsylvania brewery is thinking tropical.


It’s that time of year where most of the country braces for the cold winter ahead and breweries release their pumpkin and marzen efforts to help drinkers enjoy every sip of the fall season. But at Vault Brewing Company, there’s still tropical vibes even on the most blustery November days.  

Sure, the Yardley, Pennsylvania brewery still released its popular seasonal effort, Sweet Potato Ale, to compete with the overstocked pumpkin beer shelves but it also concocted something much different, a unique brew inspired from a traditional Hawaiian dessert.  With a fresh batch released just a couple of weeks ago, Pau Hana is what Brewmaster Ken Caldwell describes as a “haupia pie ale” that is brewed with purple sweet potatoes, toasted coconut and lactose, for a beer you won’t find anywhere else.

“I had to explain what haupia was to everyone around here and then I had to explain what a purple sweet potato was and then naming it Pau Hana – I had to explain what pau hana meant,” Caldwell laughed.  “There was a lot of incorrect pronunciations.”

Haupia is a coconut custard-like topping, a gelatinous dessert that’s made using sugar, coconut and coconut milk, that’s often plopped on top of pies.  It comes in a variety of different versions, including the most popular, chocolate haupia pie, as well as sweet potato haupia pie, a bright and vibrant purple-looking dessert made using ube, which is very similar to an Okinawan sweet potato.  But Pennsylvania is thousands of miles from Hawaii and huapia pie isn’t exactly something the locals are familiar with, so why brew a seasonal beer inspired by the popular regional favorite?  

It’s the brainchild of Brewmaster Ken Caldwell, who moved out to Hawaii back in 2016.  While working for a local brewery, Caldwell enjoyed the Hawaiian twists on typically more simplistic offerings, like a toasted coconut hefeweizen, and fell in love with local ingredients, like the ube.

“It has that bright, vibrant, purple color – like this rich purple.  The purple sweet potatoes, I became obsessed with them out there, and just that flavor they produce is just awesome.”

After two years, Caldwell elected to move back to Pennsylvania and was quickly hired to run Vault and while he focused on more straight-ahead beer with more traditional ingredients, he didn’t forget about some of what he enjoyed most from his time in the Aloha State.  And, as fate would have it, while brainstorming a haupia pie beer he came across the key ingredient.

“I was thinking about doing [a haupia pie beer] for a while, like, ‘Oh, it’d be cool to do a purple sweet potato with haupia-inspired beer,’” Caldwell admitted.  “I was like, ‘Let me just look around and see if I can find purple sweet potatoes,’ more for myself, and there’s a farmer’s market over in Morrisville.  I found the purple sweet potatoes and I was like, ‘Get the hell out of here, I can’t believe it!’  I almost willed the sweet potatoes to appear and I was just like, ‘This is great.’”

Photo Courtesy of @VaultBrewing on Instagram.

Caldwell ordered a couple of cases of the vegetable and, much like Vault’s Sweet Potato Ale, the 60 pounds of purple sweet potatoes were roasted in the pizza oven at the brewpub, to get them slightly caramelized before blending it up and throwing it into the mash.  Toasted coconut, along with lactose, was also added during brewing for an end result that’s a 7.0 percent ABV effort offering a sweet, caramelly, nutty flavor from the coconut with a heartier body from the potatoes.  But there was one thing missing from that first batch for Caldwell: a vibrant purple color like its dessert counterpart. 

Originally, the crew wanted to give it an eye-catching and distinct look.

“We were hoping to get kind of like a purplish color to it – I was a little nervous because you mix purple with most beers, how you have that yellowish color, and it turns into this weird grayish-brown almost,”  he added.  “I was a little nervous at first and I was like, ‘It’s either going to be purple, nothing at all or this weird gray color.’  It was a little nerve-wracking.”

There was plenty of experimenting, like incorporating butterfly pea powder, which becomes an indigo color when it’s mixed with something slightly acidic.  It ultimately backfired, however, turning it the gray color Caldwell was looking to avoid.  In the end, he left the color alone – but a slight purplish hue, like a golden color, comes through when drinking Pau Hana, all because of the purple sweet potatoes.  And it was achieved all without the help of any caramel malts.

Without a pilot system to brew smaller amounts, a 20-barrel batch of Pau Hana, which is a Hawaiian phrase meaning “finished working,” was created.  It was first sold exclusively at Vault’s brewpub and wasn’t canned.  Caldwell admits the reviews were mixed.

“It was kind of weird, it has like this bizarre kind of cult-like following.  It was one of those things where some people didn’t get it and didn’t even want to try it and other people tried it and liked it.”

Since it was a nitro effort, Caldwell was unable to send some of his unusually delicious new creation to his friends and former co-workers in Hawaii.  But, this time around, Vault canned Pau Hana and while it only got a small distribution, more people could take it home in four-packs.

“It’s funny, we were laughing, a lot of my friends out there are like, ‘Aw man, you must really be missing the islands if you’re making a haupia beer,’” he laughed.  “It was one of those [things where] my friends back at the brewery I was working at when I first made it were asking if we could send some out to them but, unfortunately because it was nitro, we couldn’t put it in a crowler and send it out.  So, this time around, since we decided to can it, and did the nitro cans, I’m sending a case out their way.”

Developed and popularized by Guinness, nitro is simply the process of infusing beer with nitrogen gas, which changes both the beer’s aroma and flavor while giving it a more silky mouthfeel.  Though nitro efforts are fairly uncommon, it’s nothing new – in kegs, cans and bottles.  But Vault actually changed the game on nitro cans a few years back.  In the hopes of no longer needing a widget, a plastic insert at the bottom of the can charged with nitrogen before pouring, the brewery developed the first widgetless cans – so there’s no plastic noise, just lift it straight over the glass and pour.  Available now at Vault’s two locations, there’s still plenty of Pau Hana to try – but why release it now?

As Caldwell explained, it’s a palate cleanser with a sweet taste, prior to stout season.

“I figured it’s a good time of year because people are in-between – and for the people that don’t like stouts who want something with a little more body and a little more sweetness to it but aren’t a dark beer kind-of-drinker.  The first batch was kind of a big fingers-crossed, hope it works, kind-of-thing and then put it to the back-burner for a while because it’s seasonal and you kind of have to find the right time for it.”

In the several years since introducing Pau Hana, Caldwell has yet to find another brewery creating a beer similar to it, though he has offered up the recipe and idea to some friends.

“It definitely was a my-creation-kind-of-thing but I’m real good friends with these guys out in Hawaii and they just did a version, I think they released it a week or two ago,” he said.  “These guys are called Beer Lab HI and they’re really cool – they actually, successfully got it purple!  I think they did the butterfly pea powder and some other colorings they had to use.  Other than those guys, that’s the only other people I’ve seen doing this beer.”

For now, Caldwell and the crew at Vault plan to keep Pau Hana to a seasonal, once a year, release and hope that it’ll be available around this time, or a little later, every year moving forward in the hopes of not overkilling this uniquely Hawaiian effort.  Maybe Caldwell can talk to Beer Lab HI and finally turn it purple – until then it’s time to focus on what’s next and that’s the upcoming stout season.