here is Julia's version: According to Rosa Cardini, the following is how to make a Caesar's Salad just as it was made that...
I am not sure it is spoiled if it smells a little pungent But if it tastes like ammonia, it sure sounds like it was improperly stored, or mis-handled by a cutter using a fouled knife or board, or was touched by hands that cleaned knives (ammonia takes off the wax on knife blades deposited from cutting waxed wheels While Brie is not waxed, others in the shops are ).
Most cheese is a living product. Because the mold-bacteria-enzymes that create most cheese still are working and are still giving off byproducts like methane, etc. throughout the life of the package-wheel, almost all cheeses need an hour opened out in the air to breathe before serving. Brie is one that needs an hour uncovered at room temp to "out-gas" trapped pungent byproducts.
That said - I am hard pressed to think of any natural compound in an unadulterated ripe brie cheese that would break down and create ammonia rather than create methane, without some outside help. Might be, but it seems odd to get ammonia at storage temp, given the mixes in cheese and air. However, some mfgs pkg food in gbuttes that stop deterioration (e.g., nitrogen in potato chip bags) to get longer shelf life, or they use gbuttes to comply with the regulations intended to protect against agricultural organisms (gbuttes are added to kill aerobic bacteria). While nitrogen is ok for pkging chips, I would think it would combine in the complex fats of cheese to do weird things, or promote dangerous anerobic bacteria in dairy products. If they filled it with nitrogen and then pasteurized it......
I have kept small brie and camembert wheels well beyond their "use by" dates a couple times, and it seems to take a fair amount of time to get noticeable breakdown, especially one that doesn't pretty much dissipate out during its breathing hour.
I would try an upscale cheese shop, or buy the small (1 lb) intact wheels. In the upscale shops, you can ask for a taste before buying, and if you get an ammonia taste, you can pbutt on the Brie - (tell them about the ammonia taste, of course).
Question about Brie 7379
As a followup having more time today - I usually get "President's" in the 15 oz "mini-wheel" - The parent company, Lactolais? or some such name, also distributes them in France under a different...