Why is Bleu Cheese Blue?

Bleu cheese is an interesting cheese that has a distinct flavor, distinct texture, and distinct color. If you love bleu cheese for its flavor, have you ever wondered where its color is going to come from? There of course are all the Old Wives’ Tales as to where the blue comes from, but actually knowing can be helpful. Let’s visit the reason why bleu cheese is blue so that the facts are out there and we can explain scientifically where it comes from instead of making up those fun tales.

How Bleu Cheese is Made

Part of the way Bleu cheese is made blue is through the process of making it, so to properly understand how it works, you need to first understand how it is made. To make bleu cheese, you have to start with cheese curds which are made with warm milk, rennet which causes it to coagulate, and some sort of bacterial starter which is something like buttermilk. This will sit generally for about 24 hours until the curds that you need to have been created. Then, the curds are strained with cheesecloth and stored somewhere for about 24 hours while all moisture drains. The curds are the first step to getting the bleu cheese created.

The Amazing Penicillium

To get bleu cheese to the color that is expected of it, the curds are crumbled and they are salted. From here, they add the peniciullium. Yes, this is the same thing that is used to fight off infections in people and given in either a shot, liquid, or pill form. For bleu cheese, this is the blue-green mold that actually creates the flavor and the color that we expect with bleu cheese.

Continuing the Process

Once the penicillium is in inoculated into the cheese, it now needs to be pressed and aerated. When they press the cheese, they do it to keep it dense, but to keep it open enough that there are air pockets throughout the cheese that the mold will be able to spread about. From there, holes are poked with a stainless steel rod so that the mold gets all the age it needs. When that is completed, it is time for the blue cheese to age, where it will get the blue-green color that people expect from it. That is also what makes it taste so great and makes it really enjoyable for people that truly enjoy that sort of thing.

-Written by Viktoria Carella