I've had a thought kicking around in my head for the last few days. I saw that cheese at costco, and thought it looked interesting -- not so much for the horseradish, as for it being an aged cheddar that was pasteurized processed. This comes on the heels of a discussion over in the recipes section of velveeta and nacho cheese (cheez?). I've been wondering about what would go into making a cheese at home that was good, and strong, and flavorful, but still melted down in that even, almost unholy way that velveeta does.
Anyway, the ingredient list for that cheese, plus an idea for 'pliable parmesan' on a molecular gastronomy recipe site
makes me think that trisodium citrate is the way to go. It's an emulsifying salt; not sure sure the mechanism of action, but it's been used to make processed cheese for at least 70 years now, and seems to still be the best choice. It's cheap on ebay, but I haven't bit the bullet and ordered any yet.
I'd be curious to hear how that horseradish cheddar works in a mac n cheese... it seems like all the pasteurized process cheeses are designed for, and really only good for, applications where they're melted.
I hope my ideas don't seem too heretical to the folks here. Everyone's trying to get back to authentic artisanal methods, and I'm trying to recreate the lab in my kitchen.