Whether you’re crafting a gourmet charcuterie board or spreading cream cheese on your morning bagel, Luis Jiménez-Maroto’s work is the reason beloved cheeses are a tasty — and consistent — part of your experience. A native of Mexico City, he first came to UW–Madison when a professor sought a graduate student with expertise in Latin American cheeses. After completing his master’s degree, Jiménez-Maroto returned to Mexico to work in sensory science at PepsiCo, conducting studies to ensure the consistency of products from one of the world’s largest food-and-beverage companies. Now, as an assistant coordinator for cheese industry and applications at the Center for Dairy Research, he combines centuries-old traditions with cutting-edge scientific research to keep Wisconsin dairy at the forefront of the industry. “Anyone can make cheese. But you need to know what you’re doing to make good cheese, and you need someone who understands the art and craft of making cheese to make good cheese consistently,” he says. “That’s where we step in.”
What’s something people don’t realize affects their experience with food?
Although you can measure a lot with equipment, ultimately, human perception is very subjective and very variable.
There are some nuances that really matter for people to perceive something as authentic. For example, queso Oaxaca is a type of cheese that is a sibling of mozzarella, but the shape really matters. If I’m Mexican and I go to buy queso Oaxaca and it’s a block instead of wound up like a yarn ball, I’m going to say that’s not queso Oaxaca. The little details really do matter.
For your PhD, you researched how high-pressure processing (HPP) and cold storage can extend the functional shelf life of cheese. How does that work?
HPP works by sealing food in flexible packaging, placing it in a water-filled chamber, and applying extremely high pressure. That kills bacteria and modifies enzymes and proteins but without heat.
The functionality of a cheese like mozzarella is that it should shred well and melt nicely. But there’s only a short window of time where it does that properly. After that, it doesn’t mean you’re going to get sick, but you might have a pizza that leaks liquid or cheese that’s too gummy to shred. That happens because the proteins change over time.
When we combined HPP with refrigeration, we could take mozzarella and extend its shelf life from three months to nine months. But, when you use HPP and then store it at 32 degrees Fahrenheit, which isn’t quite cold enough to freeze water within food, you can extend the functional shelf life past a year.
You still make and package the cheese the same way, but instead of just refrigerating it, you either store it colder or use HPP plus cold storage. Doing that can extend its shelf life massively.
It’s not widely used in the dairy industry as much because it's expensive and domestic cheese sells quickly. But for export markets, where cheese might spend months in transit, it makes a big difference when the product hits stores.
What’s your favorite part of your job?
I love teaching people how to make better cheese. I take the science and chemistry of dairy and simplify it into concepts they can apply. Making cheese is basically a dehydration process — you’re removing the water from milk and keeping the solids — but the way you handle that process determines the cheese you end up with. I enjoy helping people understand how tweaking these steps can lead to a better product.
Are you a dairy snob?
I would say I’m more cursed with knowledge. I joined the local chapter of the Collegiate Dairy Products Evaluation Contest, where we were trained to evaluate whole milk, strawberry yogurt, cheddar cheese, cottage cheese, ice cream, and butter. We learned to identify specific defects in these products and how to deduct points from a perfect score of 100 based on the type and severity of each defect. For two years, I woke up really early in the morning to go taste milk, and it ruined milk for me because now I know what the defects of milk are.
If it’s perfect milk, I’m super happy. The problem is that the most common defect in milk in the U.S. is light oxidation. It can happen within 20 minutes, but if you go to the store and buy a pint of milk, it’s in a translucent container sitting right next to the light. So, to me, milk always tastes oxidized, but for most people, that’s just the flavor of milk.
What’s your favorite cheese?
If I had to choose one cheese and I can’t have any other cheese ever again, I would go with a sweet parmesan, like a BellaVitano. It’s versatile — slightly salty, slightly fruity — and I’ve never given it to someone and had them say they didn’t like it.
Is there a variety of cheese you find especially interesting?
Blue cheese is fascinating. It starts its life basically being feta, but then you pierce it, and the mold grows, changing the flavor. To try it, eat it with something else, as it’s too intense on its own. It's not for everyone, but I recommend starting with a blue cheese dip, like with cheese curds, to see if you like it.
Photo courtesy of the Center for Dairy Research.
