The Science of Fondue

Swiss and Pancetta Fondue

Swiss and Pancetta Fondue

Today is National Cheese Fondue Day, and we’re celebrating by melting a few of our favorite Wisconsin cheeses into creamy, cheesy goodness. But before we dip in, we thought we’d take a look at science behind this classic cheesy dish.

Pat Polowsky is a food science graduate student, part time cheesemonger and author of the Cheese Science Toolkit, a site dedicated to the science of cheese.

When it comes to fondue, we think cheese, wine and maybe a few other ingredients. Melt, dip, repeat. Easy, right? Well, according to Polowsky, there are four important factors at play behind the scenes in our fondue pots:

Protein — Casein protein is the structure of cheese and its interactions are what dictate how cheese melts and how stable a fondue will be.
Calcium and pH — There is a delicate balance of acidity and the resulting calcium-balance that influence how well a cheese will melt.
Moisture — The amount of water in the mix will help influence melting.
Fat — The amount of fat and how will its incorporated will dictate whether a fondue is silky smooth or an oily mess.

Understanding emulsion in fondue

Graphic courtesy of Cheese Science Toolkit

Understanding Emulsion

What’s the key to a perfectly creamy fondue? (Besides plenty of Wisconsin cheese?) The answer is a stable emulsion. Polowsky explains:

An emulsion can be thought of as a dispersion of one substance in another. What’s special here is that those two substances don’t want to mix together. A classic example is trying to mix together oil and water. If you shake it really well, you may get them mixed for a bit, but they will eventually separate. To keep them mixed, you need the help of an emulsifier. Emulsifiers help keep the two parts of an emulsion together, preventing them from separating (or “breaking” as it’s called).

The most traditional fondue emulsifier is white wine. It contains tartaric acid, which acts as an emulsifying salt in fondue.This helps to create a that smooth consistency you want in a fondue. “Simply put, tartaric acid in wine (and citric acid in lemon juice) is changing the cheese protein structure allowing it to hold onto fat better,” Polowsky says.

To learn more about that process and how other fondue ingredients can affect its scientific structure, head over to Cheese Science Toolkit.

Ready to get cooking? Try one of these fabulous fondue recipes from our collection: