In the middle of notebooks and duct tape and measuring cups and water bottles, one item stood out atop the custom-built work cart at Mountain Laurel Spirits:

A giant yellow bag of Peanut M&Ms

Of all the devices, gizmos and equipment scattered throughout the 11,000-square-foot Bucks County facility, those candies might be the most important tool when it comes to blending whiskey.

The process involves a lot of tasting — sniffing and sampling and swishing and swallowing — and the liquid in question is high octane. Very high. At cask strength, pulled from one of dozens upon dozens of charred oak barrels, Dad’s Hat Rye is around 120 proof, aka 50 percent stronger than your standard bottled liquor.

As I discovered on a recent visit, that stuff goes to your head quick. Even when you’re good at heeding distillery co-founder John Cooper’s directions and only sipping a tiny bit from each specimen he pours.

That’s what I did, partly because I was keen to avoid getting sloshed, but also because I got a miniature thrill from jauntily tossing the rest of the liquid onto the concrete. As the cart moved through the barrel racks, it left a quickly-evaporating trail of Jackson Pollack splashes on the concrete. “We used to try to save it, but realized it wasn’t worth the effort,” said Herman Mihalich, the distillery’s other founder. “Gotta keep the angels and fairies happy.”

Tasting whiskey is hard work

Even though I followed instructions and took only small sips, my face was definitely flushed by the end of the afternoon.

Could have been worse; not everyone takes Cooper’s advice. “We had one fellow here for a tasting session who wanted to show off, or something, and drained the whole glass each time,” Cooper said. “Turns out he’d also been finishing other people’s glasses when we weren’t looking. At the end, we went to sit down in the tasting room, and — thunk! His head dropped right on the table. Totally passed out.”

So yeah, snacking on M&Ms along the way helps.

Bites of nut and chocolate are also useful to avoid olfactory overload. The sharpness of high-alcohol whiskey can be rough on the palate, and when you’re selecting which barrels to make into a custom blend, every taste bud counts.

Even when it’s made from grain pulled from the same 2,000-lb. bag of Pennsylvania rye, blended in an 80/20 ratio with the same batch of malt, fermented in the same 2,000-gallon tank and distilled through the column still on the exact same run, once it’s had 8½ months of aging in wood, booze from each barrel tastes surprisingly distinct.

“It’s all about the balance between spicy and floral and fruity and woody,” explained Mihalich before we got started.

Cooper was more erudite. “To me, this one starts with pepper on the lips, slides into cinnamon on the mid-palate, picks up raisin on the tongue, adds tobacco around the edges and finishes with vanilla and black cherry,” he said, a twinkle in his eye.

I raised my eyebrows. “Uh…I get the pepper part, sure.”

Gotta keep the floor fairies supplied with booze Credit: Danya Henninger/Billy Penn

After a few more rounds of samples, each one pulled from a 15-gallon cask with a long, glass whiskey thief (and interspersed with M&Ms), I definitely began to appreciate more nuance. Some were almost lemony, others bore a flavor more like plum. A few were extremely spicy, others much more mellow.

All in all, we tasted nine different barrels. And then had to make a decision.

Our goal was to create a new addition to the Dad’s Hat Rye lineup: A limited-run blend. They’d done custom editions in the past, but only for private events or groups or charities. Mine would theoretically end up on store shelves.

Which meant, Cooper pointed out, that it should taste different from what’s already out there.

Dad’s Hat was one of the earlier entries into the now-booming craft spirits market — Mountain Laurel was the state’s first whiskey distillery since Prohibition. The signature product, Pennsylvania Rye Whiskey, is now available in 17 states and 24 countries around the world. It’s made of whiskey aged at least six months in dozens of different barrels that are then mixed together in a large stainless steel tank before being bottled at 90 proof. The tank is never allowed to run empty, so the older batches mix with the new — there’s at least a few molecules of the distillery’s original 2012 batch in every bottling, and the spicy, peppery flavor stays consistent. In 2015, Whisky Advocate named this its Craft Whiskey of the Year.

Last June, Mountain Laurel Spirits expanded with new equipment and an extra room to hold the growing collection of barrels Credit: Danya Henninger/Billy Penn

A second stainless steel tank holds Dad’s Hat Straight Rye Whiskey. The deep red liquid has aged much longer (at least three years) in larger, 53-gallon casks. It’s richer and smoother, and is bottled at 95 proof.

Mihalich and Cooper — who met as fraternity brothers when they were at Penn, btw — have also sold versions of their rye aged in vermouth and port wine barrels, and are currently aging liquid in barrels that previously held maple syrup. (That rye-barrel-aged syrup, a collaboration between Dad’s Hat and Grinarml’s Maple Syrup Company in Somerset, Pa., was released last November and is available for purchase online.)

The one we created for me would have to have its own character, separate from any of those. No pressure, right?

No worries. Cooper swooped in with a solution.

“I was watching you,” he said with a knowing smile. “Sometimes people say one thing, but if you look at their expression as they sip, you can tell what they really think. We’ll do your two favorites.”

He pointed to the second barrel we tasted, pulled from the racks along the back wall. “That peppery one,” he said, pivoting to face the door, “and the one you said tasted like raisin.”

Sold. Cooper put the bungs back into the open casks and covered each one with a piece of tape marked with my name.

On March 1, I’ll head back to the Bristol facility to help with bottling. Soon thereafter — assuming I don’t break any equipment or spill the whole batch on the ground — you’ll be able to buy a bottle. Stay tuned.

One of two barrels that will be blended for our custom, limited-edition bottling run Credit: Danya Henninger/Billy Penn

Danya Henninger is a Philadelphia-based journalist who believes local news is essential for thriving communities, and that its format will continue to evolve. She spent six years overseeing both editorial...