Once upon a time, I was known as the “forefather of the craft chocolate revolution” by food writers apparently in the know.

I’m not sure exactly what that means, but I certainly was born with an affinity for good chocolate, and a molecular fascination for what makes things taste delicious. For almost two decades, I applied that confluence of ability into making award-winning (and unique) chocolates at the helm of Patric Chocolate.

Nowadays I’m a food science consultant…and at the request of Dr. Gregory Ziegler at Penn State University, I’m also a visiting professor at PSU’s week-long chocolate short course, which is what this story is all about.

Haven’t heard of it?

Well first let’s step back in time a bit…

Why is Pennsylvania the chocolate capital of the United States?

Since before the colonies became America, Pennsylvania has been home to a large population of German immigrants, who brought their chocolate-making traditions with them.

Pennsylvania was also home to one of America’s first deepwater ports—which meant heavy freighters could bring in raw materials (like cacao) cheaper than elsewhere.

As a result, some of the world’s biggest chocolate manufacturers are in Pennsylvania:

Callebaut
Blommer
Hershey’s
Wilbur
Innumerable smaller manufacturers

So why is all this relevant?

Well, because of its proximity to the center of so much chocolate, the Penn State Food Science Department has been doing commissioned research on the bittersweet stuff for decades. The university is far and away the locus of chocolate research in this country (and dare we say the world?)

Through the years Penn State has boasted some extraordinary and esteemed faculty, including Dr. Greg Ziegler; who’s probably the closest thing that we have in this world to a rockstar in chocolate academia.

The university’s food-science building is his stage; and he’s built it up to be nothing short of mindblowing—including a top-of-the-line pilot plant with an incredible array of chocolate equipment for students to work with.

Which is why it was so exciting for me during my PhD, to work with PSU food-science faculty and talk to Greg Ziegler about his thoughts about the sensory portion of my project.

It was a little weird when I first met him and his fellow faculty (including Dr. Helene Hopfer) about my PhD project: Apparently they already knew who I was because of Patric Chocolate. It made me feel a little shy. But they were excited to have me, so I was excited to go.

In fact, my chocolate-handling experience helped inform the sample preparation that we did there for my PhD project. Some of the decisions I made back in 2019 are still informing how grad students working in chocolate at Penn State are doing things today. But that’s another story…

2nd Annual Penn State Chocolate Short Course

Fast forward a few years, and Patric no longer manufactures chocolate…but the legacy continues through the Penn State chocolate short course

A distinguished faculty member of PSU’s Department of Food Science, Dr. Greg Ziegler is the mastermind of this educational event. Featuring yours truly, along with several other very talented chocolate experts. Here’s the whole list:

2023 PSU Chocolate Short Course presenters:

Dr. Alan McClure, Patric Food & Beverage Development / Patric Chocolate
Dr. Helene Hopper (PSU faculty who advised on my PhD project)
Sarah Barath, a cacao fermentation scientist based in Trinidad
Greg D’Alesandre, a chocolate business expert & co-owner of Dandelion in San Francisco
Lorenzo Datei, a chocolate machinery specialist with PackInt in Italy
Dr. Jasna Kovac, a microbiologist from Penn State
Dr. Abby Snyder, a microbiologist from Cornell
Dr. Joshua Lambert, an expert in the health benefits of chocolate at Penn State

Penn State invited me to launch the first chocolate short course with them in 2022, with a 4-day series…but this year we extended it to 5 days.

Participants come from all over the world, to learn the bittersweet secrets of making the best chocolate possible.

And boy do we put on a show for them. Full 8-hour days, immersed in the science and craft of chocolate. Mmm, just thinking about it makes my mouth water and my mind wander…

Oven roasting vs drum roasting cacao for chocolate

Like many science-based university classes, this short course I taught included a lecture and a lab component.

I talked about the science of roasting, the importance of experiment design, and the critical Maillard effect (the non-enzymatic browning that occurs through various means).

Then demonstrated both roasting processes in PSU’s beautiful, well-equipped chocolate lab. So participants could see firsthand the differences in speed, labor intensiveness, mess from breakage, and the ease of monitoring roast changes at the single-bean level, among other decisive elements.

Later students made chocolate using the two different cacao roast methods to compare how each method affects the final product.

Tempering chocolate without a thermometer

For this next class, I talked a bit about the science of chocolate tempering, though Dr. Ziegler had already covered the topic in fine detail. Tempering is all about carefully controlling the temperature of chocolate so the cocoa butter crystallizes in the most stable alignment possible. Read more details about this process here.

For the lab component, participants learned the traditional chocolate-making process called marble slab tempering.

First, melt your chocolate and any flavor ingredients in a double-boiler or other system to keep temperatures even and prevent burning.

Then pour a manageable portion of that onto a marble slab, and apply shear with a metal scraper to move it around across the smooth, cool surface—until it starts to set up a bit and gets just a little viscous.

Scrape that up and stir it back into the melted chocolate. The cooler stuff brings the overall temperature down a little bit—but it also adds some number of stable cocoa butter crystals to the mix.

The goal is to have the right proportion of small cocoa butter crystals to liquid cocoa butter. When you get that ratio just right, the chocolate is tempered. Then you can mold it into bars, enrobe confectionery with it, or whatever you want.

How do you know if chocolate is tempered?

I told the course participants that I’d show them how to temper chocolate perfectly without once using a thermometer.

No way, they said. Is that even possible?

After working through a few rounds of the marble slab method, I showed them my “knife trick” for checking chocolate tempering. It’s something that I’d read about years ago from some skilled confectioner that seemed so smart to me, and I immediately incorporated it into business as usual at Patric Chocolate.

Here’s how it works: Once the molten-but-cooling chocolate is nice and smooth after one or more additions of crystals, you simply put in a knife or other thin flat tool. Just get a thin layer of chocolate on it, kind of shake it off, and then set that knife down on a piece of parchment and just let it set.

If it doesn’t set very quickly, it’s not tempered.
If it sets but takes a while, it’s partially tempered (or under-tempered).
If it sets pretty quickly, it’s in temper.
If the melted chocolate is already kind of thick, and sets almost immediately, it’s over-tempered.

It takes a bit of trial and error, but it’s very easy to see just by watching how long it takes a thin layer of chocolate set up on a butter knife on a piece of parchment. You don’t need to know the temperature. And the appearance helps to confirm your feeling about the speed of chocolate setting. You can hold the chocolate-covered knife up to the light and see how well light reflects off of it. Is it super glossy? Tempered! Is it really spotty? Needs more seed crystals.

By the end, everyone was able to do it—and no one had ever done it before! It was very exciting.

Why attend the PSU chocolate short course?

One of the greatest things about this year was that everyone got to take home chocolate that they made during the short course, using what they’d learned. We’ll definitely continue that.

Participants also get a course-completion certificate with Penn State Food Science Department’s seal—which you can put on your website to impress visitors.

Overall the Penn State chocolate short course was an amazing experience for visitors and teachers alike. Networking, socializing with other chocolate nerds, sharing ideas and stories and chocolate, chocolate, chocolate…

Frankly, everyone who wants to know about making, handling or even selling chocolate needs to attend this thing at some point. There should be no question in your mind.

Stay tuned for more about next year’s chocolate short course!

Questions? Contact me