I’m living proof that algebra is essential after school.

I learned this during a recent visit to Bucks County to bottle my special blend of Dad’s Hat Rye. The blend turned out to be a resounding success, by the way, resulting in a whiskey that starts out peppery and finishes round and smooth. (It’s now available to buy, too; more on that below.)

But first, that algebra. Because it takes math to bottle whiskey. A lot of it.

Once whiskey is pulled from the barrels where it’s aging, and filtered to remove woody residue, dilution is the task at hand. Most whiskey is not bottled at cask strength, since distilleries want you to enjoy their products and not burn the hairs off your throat from the inside out. Determining exactly how much water to add to the raw spirit before putting it in bottles is complicated — and critical.

It’s not just about optimizing the flavor; it’s about complying with the law. Federal Alcohol and Tobacco Tax and Trade Bureau rules allow for very little discrepancy between what’s printed on the label and the actual percentage alcohol of what ends up inside.

“You have to be between 0.3 points under and 0.1 point over,” explained Mountain Laurel Spirits co-owner Herman Mihalich. He noted that the TTB doesn’t do spot tests all that often, but it’s worth the effort to be ready for them. If you do get caught with a proof that’s outside the allowable tolerance (which has never happened with Dad’s Hat, Mihalich said), the agency can issue a fine or even shut down production entirely until the issue is sorted out.

Calculating the cut

We decided the Danya Blend (!) would be bottled at the same strength as regular Dad’s Hat, or 90 proof. Whiskey usually comes out of the barrels at around 120 proof (although not exactly), so we knew we needed to add a bunch of water. But how much?

Luckily, I wasn’t tasked with figuring it out.

Not that I’m horrible at math — geometry was my favorite subject in high school — but that was back in…well, a long time ago. And Mihalich and partner John Cooper had the man for the job. Last summer, they brought on Travis Scott as assistant distiller, and the recent Drexel grad was on top of it.

“I went through the accelerated program to get a combined bachelors and masters degree in chemical engineering and now I’m stirring a big vat of whiskey,” Scott said as he pulled a paddle back and forth to mix the first addition of water into the whiskey blend. “But,” he added, “I’m not upset about it.”

He continued the process for the better part of an hour, periodically testing the proof of the liquid by measuring density with a hydrometer and taking the ambient temperature and looking up the alcohol percentage in a big book of charts. Eventually he was close enough to 90 proof that he did one last volume measurement and poured in the last carefully measured pitcher of water.

The need to perform quick calculations before bottling is one of the main reasons not to steal too many nips while you’re doing it — unless your special power is that you do math better when you’re tipsy, I guess — but there are definitely others.

People power

When it’s going full steam, the bottling system at Mountain Laurel Spirits can fill, seal and box around 900 bottles of Dad’s Hat Rye each hour. The most the company has ever done in a single day is 2,250 bottles. That number is even more impressive when you realize the bottling system is just a bunch of people forming an assembly line in front of a stainless steel table.

At one end of the line, someone’s in charge of carefully overturning cases of empty bottles to keep the prep table stocked. Here’s the first reason you don’t want to be drunk — one false move and you could have shattered glass all over the floor.

A second person grabs the empties and slots them in beneath the spigots of the four-bottle filler, then pulls them out when they’re full of booze. Case two for not drinking on the job: This looks easy, but takes quite a bit of coordination — even someone as experienced as Cooper ended up with a spill during my visit.

Third up is popping in the corks, which take a hard push to fully close. (It’s the kind of motion that could easily catch and pinch your skin.) Fourth is sliding on the black sleeve that will seal the cork in place, which brings us to the step that poses the most danger to booze-addled people: Heat-shrinking that seal in place. This is done with a heat gun that blazes at more than 1000 degrees, so if you don’t have full motor control as you’re lowering it over the top of the bottle, you could end up with a seriously bad burn.

How to get the special blend

Although Cooper did warn me a few times to watch where I was holding the hot sealer, I’m happy to report that I spent time at each position on the bottling line and emerged with zero injuries.

I also emerged to find 60 bottles of whiskey with my name on it — and now it’s up for sale.

Why would you want the Danya Blend, you may ask?

The spiciness of rye is one reason I’m a big fan, and why I generally prefer it over bourbon, which has a much sweeter taste. However, Dad’s Hat in particular is extremely “hot,” with a very sharp bite that can leave your tongue stinging when you sip it straight. My blend tempers that finish. It still starts out sharp and spicy, but has a slightly sweeter endnote filled with cocoa and plum.

Rigorous tests with a sample bottle showed my blend works best in booze-heavy cocktails like a Manhattan or Old Fashioned. It’s also delicious sipped on the rocks, or neat with a splash of water. A little too delicious, even.

Danya Blend is priced exactly the same as regular Dad’s Hat Rye ($38.99 a bottle). Anyone can buy a bottle by visiting the distillery, which is a stone’s throw away from the Bristol stop on SEPTA’s Trenton line (a facility tour makes for a nice Saturday afternoon activity).

Bar managers, on the other hand, can call the distillery and have their order delivered direct to their establishment’s door. Bonus: If you order it and let me know, I’ll plan a night to swing through and buy a few drinks to give away and spread the good word.