Anatomy of a Munchkin: Sneaky lessons in product design
Engineers see the world with a unique lens, and we’re grateful that they do. A prime example is our cofounder Sam Holland, who’s a talented mechanical engineer and product designer. When he’s not deep in the throes of designing and testing technical products for our clients, he’s busy thinking of the technicalities of donut holes, specifically Dunkin’ Donuts Munchkins. Why? Simply put: because he loves to eat them almost as much as he loves to engineer and design. Enter Sam’s Donut Hole-der! He’s invented that which no one knew they needed — until now. His Munchkin dispenser can clip on your belt and hold three Munchkins (or six, using the extender). But the best part is that not only has he documented his development process on his dedicated blog Dear Dunkin’, you can have fun learning about product design by reading his posts. Play, after all, is essential to innovation. Here’s his latest post to whet your appetite.
People like to spend their weekends differently. I know folks who go for bike rides or sleep in late. Some love reading a great book and getting cozy. This weekend, I bought a crapload of Munchkins and measured them. I learned a lot and want to talk about it too much.
Munchkin history
Let’s start at the beginning. According to the internet, Munchkins were invented due to a need to reuse the dough from the center of a donut — a.k.a. the donut hole. Initially, the centers were rolled into new donuts, but they were too tough. There are many theories on who came up with the idea to simply fry up the center part, and I don’t want to get myself in hot water by attributing the wrong person here, so I’ll just say that it happened and it was really smart.
They were sold under the name “donut holes” (creative!) to limited success. Things get problematic here quickly, but you need to keep in mind it was the 70s. It wasn’t until they were rebranded to “Munchkins” after the characters in the Wizard of Oz that they really took off. This commercial is pretty messed up and wouldn’t fly these days, but it was a hit back then! Munchkins were targeted to children, folks on a (limited) diet, and as a nice little snack.
Holding Munchkins
Designing a product like the Donut Hole-der means I need to make some assumptions and decisions on things. I decided the carrying capacity should be 3–4 donuts for the sake of ergonomics and health (180-360 calories, depending on quantity and type). I needed to also determine what size the holder should be to store the average Munchkin, which is how I found myself measuring two dozen donuts on a sunny afternoon. As it turns out, these puppies vary in size and shape a lot! I also learned there are two major categories of munchkins. Still with me? Let’s dive in deeper.
Munchkin categorization
In my comprehensive research, I’ve determined there are two main types of Munchkins from which all others are derived: “fried balls” and the “pillowy loafs.”
The two main types. Learn them, share them, respect them.
The fried balls are created by dropping a measured amount of dough into a frier, creating a nice dense bite-size donut hole. They then can be topped with things like sprinkles or butternut crumbles (yes please), or glazed. The pillowy loafs seem to be far more … pillowy, which makes them great for filling with things like jelly or Boston Kreme. Nobody knows how these are manufactured, but they too can be glazed. We’ve all seen this chart before, but I’ll share it again:
Now, as anyone who has savored a Munchkin will tell you, they’re not perfectly spherical. This simply has to do with the manufacturing process. Dropping dough from any height will stretch it from a sphere into an ellipsoid due to gravity. One way to potentially alleviate this issue would be to create a sort of shot tower where the Munchkin is somehow air fried as it drops from a sufficiently high distance, but this seems impractical. So we’re stuck with ellipsoidal Munchkins and that’s OK with me.
This is an ellipsoid. The a, b, and c dimensions can be the same or different. (Image: math.net)
The importance of durometer and uniformity
The key requirements for designing a reliable dispenser are having a repeatable dimension and hardness. It’s difficult to make a product that can hold a variety of different sized objects reliably, and it’s difficult to dispense things if they’re squishy. Let’s see how Munchkins compare to some other food:
We all want to be in the zone of possibility.
As we move away from the hard and uniform items, they become more difficult to design around. Hotdogs are soft but pretty damn uniform, so they’re much easier to dispense. Tater tots get a bit harder due to the softness, but a sufficiently fried one should be dispensable. Gnocchi would be very difficult.
One fun anecdote here is that I’ve found that stale donuts tend to work better than fresh ones, as they’re harder and less sticky.
Approximations for the sake of simplicity
The dispenser is essentially a tube filled with donuts with a flap that opens to drop one out. Anything that fits within the diameter of the tube should slide right through. An ellipsoid is defined by three dimensions, but we can treat our donuts like a spheroid (an ellipsoid with two equal axes) to simplify things for measurements. The smallest dimension will obviously fit inside the tube.
Simplifying these shapes to spheroids make it far easier, right?
Cool, now we’re finally ready to take some dimensions! I recorded the longest and the second longest dimension for each donut as well as the type. I then ate each donut. Please note that I’m using millimeters here because they’re the superior units.
Now, the statistically inclined reader may point out that this is too small of a sample size to draw any significant conclusion from — and to that I say yes. I will continue to purchase, measure, and consume Munchkins (in that order) until I feel more confident in my data, but I need to give my body a rest. I, too, was disappointed in the lack of butternut in this variety and will ensure I get more data soon.
I don’t really care about the major dimensions here, as that is essentially the height of a donut. The minor dimensions, however, impact how I size the tube that holds them and how the dispenser mechanism works. Unfortunately, the range here is substantial at 16mm between the smallest and largest. In order to accommodate this range of donuts, I would have to spend more time here than I really want to on a complicated mechanism — increasing the cost and complexity of the device.
Cross section of the holder with a 42mm circle.
Instead, I designed my holder to work with the middle 75% of this range, which falls between 32 and 42mm. This is still a range of 10mm but that’s far easier to design around. This is a key lesson I’ve learned in my days of product design: It’s nearly impossible to design for everyone or every case. Instead, it’s far simpler and faster to design for a majority. This is especially easy for me to justify since the Munchkins are $0.50 each.
Lastly, I’ve ranked all Munchkin types based on flavor. Butternut is king, and the dry powdery guys are really bad. The worst are the flavorless old fashioned and the sneaky blueberry — mostly because I think it’s something else each time and get surprised. These are the official rankings now. It has been decided. Fight me.
Ranking flavors like the kids do. Butternut is so sigma. Skibidi toilet?
In conclusion
So, here we are. I tricked you into learning a bit about product design and about statistical analysis while talking about donuts. I hope you’re not too mad. We learned that like humans, each munchkin is a unique and flavorful creation! We also learned how it’s hard to design things that work for all use cases and that I might be a bit lazy.
A reminder to share this with anyone remotely connected to Dunkin’ so we can all go pontoon boat riding this summer.
Next time, I’ll dig into how I plan to design this thing for mass manufacturing.
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