Today, like many days, I bought some Camembert, but today I bought some wine too. Cheese and red wine. Excellent.
Having already had a little bit of cheese and wine and returned the cheese to the fridge, my house mate – also a fan of cheese – returned. “Look what I got” producing the partially eaten round from the fridge.
Opening and inspecting it I noticed what appeared to be blue mold: This pissed me off. But after fuming about my local shop for a bit I remembered that earlier, in my eagerness for booze, I had splashed wine all over the table and partially over the cheese. There was no sign of the red wine, perhaps the blue-grey, moldy looking stain was what became of it.
Adding a drip of wine to the cheese confirmed it. The red blob turned blue, almost fast enough to see with the naked eye. This was pretty surprising (though it doesn’t seem so now I know why).
Recently, a friend of mine has been encouraging me to take the attitude of experimenting whenever possible, I expect he might say something like: “Even if you know the answer, or exactly where to look up the answer, this doesn’t matter. What matters is actually doing things and testing ideas for yourself.” Lead by example…
Time for some kitchen science!!!
First I had two distinct types of idea about what could be happening with the cheese and wine:
- It could be a reaction of the mold to the alcohol – the production of blue indole related compounds by fungi under stress, or just whenever, is well known. In this case, perhaps alcohol would be the trigger of the stress, perhaps just getting wet.
- It is a chemical reaction of the wines “red” (yes, I’m reifying, what of it :P ) in some way.
Is it the alcohol or the red which makes the colour.
So, I tested three conditions – dabbing a bit of each the following on some Camembert rind – (left to right) water, some Norwegian applebooze (no white wine to hand) and red wine. Here’s the results, setup shown above:
Of course all materials were disposed of properly (with a water biscuit and onion chutney):
Seems that it is the redness. One more control though, remove the alcohol from the wine – by heating for a while, occasionally replenishing the water.
This has the effect of either boiling off or oxidising the alcohol. One can tell that it is complete by how disgusting the resulting liquid tastes. This produces the same result:
Clearly the red of the red wine is at work here. What is happening chemically? Is it some complex biochemical reaction or is it something simpler?
I couldn’t help noticing that the cheese and wine goes the same colour as peoples teeth when they drink wine. Mouths are alkaline, wine is usually acidic. The most obvious thing to do next is to change (increase) the pH of some wine. Not having any good bases to hand, I had to settle with baking powder (which contains rice flour annoyingly). This should make the solution a bit alkaline. Dilute a splash of wine in water to save on both wine and baking powder.
Behold the blue-grey goo!!!!
Mystery Solved. It’s the pH of the cheese that causes it.
Now, doing what I would have done if I was using the just looking it up method. Wikipedia is a good start (and often end). Looking at what gives the flavor, (link) we see that ammonium is a significant component. Being a strong base, this is no doubt an important contribution to the pH of the cheese. Further googling reveals that more mature Camemberts have a greater pH, it increases with age and distance from the center – the crust has the highest pH (link).
More on the chemistry side, this sentence is intended more a medium for links than an explanation: the colour of red wine is dominated by Anthocyanins, which change colour with protonation. The protonation affects the conjugation of the molecule and it’s properties as a chromophore.
Science Works Bitches! ;)