What determines how well cheese melts

Question

I have had my fair share of eating cheese and experimenting with them. Sometimes they come out heavenly while other times, it turn out to be a huge flop. Usually when it flops, it's because I am expecting the cheese to melt and it doesn't.

So my question is, what properties of cheese determines how well the cheese melts? This way I can determine in the future whether a cheese I am about to experiment with is meltable. Are there physical indicators that I can see and feel that can help me determine a cheese's meltability?

Is there a special way to increase how well cheese melts? I have noticed that some cheese melt slightly on the outside but the inside turn rubbery and doesn't melt.

Answer

Three factors influence how well cheese melts:

The amount of moisture,
The amount of fat,
How it was set.

The meltiest cheeses have a lot of moisture and fat and were set with rennet and not acid. Both moisture and fat leave space between the casein proteins that allows them to move. Otherwise they are packed together and don't flow as well.

Acid set cheeses don't melt much when heated dry because the acid denatures the casein in such a way as to cause it to bind more tightly.(although they will dissolve into hot liquids sometimes.)

This link is not authoritative but jives with my personal experience:
http://www.yumsugar.com/Burning-Question-Why-Do-Some-Cheeses-Melt-Better-Than-Others-2946119

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How can I melt cheese for dipping?

Question

I love dipping things like pretzels in metled cheese.

I've done this lots of times at fairs and other places with 'pretzel carts', but I've never been able to replicate it myself at home.

Whenever I try it, I get really thick, stretch cheese with a layer of liquid oil sitting on top of it. It's gross, and not good for dipping.

So, how can I melt cheese into a nice, smooth, liquid that I can use for dipping in?
I'd love to learn if there's a particular type of cheese that will work best, how to heat the cheese, and any other tips that you can provide.

Thanks!

Answer

Normal cheese melts like that. It is made of proteins, fats, and water, and these separate when they are heated.

For dipping, you need processed cheese. It has additives which keep the fat, fluid and solids mixed in a smooth mass. Also, it really helps to use very slow and even heat. This is the easy option.

If you want to do it "for real", without processed cheese, you have to make a cheese fondue. It is traditionally made with Swiss cheese (I am fond of Appenzeller fondue), but you can use most types of semi-hard yellow cheese. It also contains some fluid, traditionaly white wine, and is emulsified with simple starch. It is preferable to have a special pan for this, as you can serve it heated. But if you make a big portion in a pan with a high thermal capacity, and make it immediately before serving, you can do without the special gear.

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