If you’ve ever opened a Brie and wondered why it smells a little like a cleaning product, don’t write it off just yet. A touch of ammonia can actually be a normal part of the cheesemaking and ripening process. The key is knowing when it’s a sign of a beautifully ripe cheese—and when it means things have gone a little too far.
Where Does the Ammonia Come From?
As cheese ripens, bacteria and enzymes break down proteins. One of the natural by-products is ammonia, which can become especially noticeable in soft-ripened cheeses.
Bloomy-rind cheeses such as Brie and Camembert are common examples. The white mold on their rinds helps break down proteins and fats, creating that soft, creamy texture and developing flavor. Ammonia can be part of that process.
Washed-rind cheeses, including Époisses, Taleggio, Munster, and Limburger, can also develop an ammonia aroma. Their rinds are treated with brine, alcohol, or other solutions to encourage beneficial bacteria, which can contribute to those famously big aromas.
A Little Is Normal
Ammonia is often most noticeable right after opening a package because the gases have been trapped inside. Before deciding your cheese has gone rogue, let it sit at room temperature for 15–30 minutes. This gives the cheese a chance to breathe and allows some of the ammonia to dissipate, revealing its more complex aromas and flavors.
If that sharp smell fades, you’re likely in good shape.
If it remains overpowering and the cheese tastes harsh, bitter, or unpleasant, however, it may have ripened beyond its ideal eating window. An excessively runny or broken-down texture can be another clue.
Give Your Cheese Some Breathing Room
Storage can play a role, too. Cheese stored in tightly sealed plastic or airtight containers can trap ammonia beneath the rind. Breathable cheese paper or wax paper is a better option. Keep cheese refrigerated in a consistent environment—around 36–45°F (2–7°C) is a good general range—and avoid letting soft-ripened cheeses linger too long.
So, the next time your Brie smells a littlestrong, give it some time to breathe. A hint of ammonia can be part of the magic of ripening. When it starts smelling more like the cleaning aisle than the cheese counter, though, it may be time to call it.
You can tell by the color of the Brie if it’s a dark brown it’s over the hill