Cheddar Cheese

One of the key ingredients of worcestershire is tamarind which imparts a sour note. There are other flavors as well but I would suspect that the reason for a splash of worc. is the tanic and acidic qualities. I'd imagine it's similar to adding a pinch of brown sugar to a chili sauce, or just a pinch of nutmeg to a mornay sauce. Our taste receptors are generally limited in the classification of taste we can perceive. The combinations are what create the music. When you can open up receptors that are trained for sour, sweet, etc. You can create the sensation of a richer taste.

Edit: You want to open up the receptors of sour, sweet, salty, etc without actually making that a perceived taste in the dish. For example in a chili sauce, with a dash of brown sugar or honey, you'd never call it sweet, but you will still sense a deeper more rich flavor, as far as I know that is the goal.

Some flavors have affinities for one another and thus classic combinations are born that are repeated across many recipes. There are a couple of good books out there on flavor combinations. My favorite is The Flavor Bible. Some of the information on flavor affinities in that book is also available in the book Culinary Artistry, which a lot of people like because it covers a lot of other information besides flavors. The authors are the same. Page and Dornenburg.

IMO the only reason to add worcestershire and our a pinch of colemans is if you are using an immature cheddar for your sauce.A quality mature cheddar has more "notes" than Beethoven.

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