Should You Keep Your Ketchup in the Fridge or Not?

It's a question I've never even considered, but the Twitterverse seems to be all over the whole 'Should ketchup be stored in the refrigerator or the cupboard?' issue. I usually keep mine in the fridge because that's what Mom always did and Mom is always right. Right?

This rollicking debate apparently started when a British website called Which? asked the experts which condiments should be stored in the refrigerator and which didn't need to. Then the Twitterverse got involved and the rest of the self-proclaimed experts voiced their opinions.

One person went so far as to say, "People that don't keep ketchup in the fridge are psychopaths."

A quick web search brought up the Reader's Digest page which seems to have the definitive answer. According to the Heinz Ketchup people,

Because of its natural acidity, Heinz Ketchup is shelf-stable. However, its stability after opening can be affected by storage conditions. We recommend that this product be refrigerated after opening to maintain the best product quality.

So there you have it. Before it's opened, no. After it's opened, yes.

Now we can get on to the serious question, Is it Ketchup or Catsup?