A Field Guide to Chocolate Bars

Most chocolate bars in the candy aisle are built from the same handful of parts: a chocolate coat, and something inside it. Nougat, caramel, peanuts, a cookie, or nothing at all.

Once you know the parts, you can read almost any bar at a glance. Here's the field guide.

Chocolate starts as cocoa beans, the seeds of the cacao tree, which grows in a warm band either side of the equator. The beans are fermented, dried and roasted before they're ground. Milk chocolate adds milk and sugar to the cocoa, which is why it's softer and sweeter than dark.

The Million Dollar Bar is the plain version: a thick slab of creamy milk chocolate in a wrapper printed like a banknote.

Nougat is a whipped sugar mix, usually made light with egg white. In candy bars it's soft and chewy. Caramel is sugar cooked with milk or cream until it turns golden and stretchy.

Put the two together under milk chocolate and you get the Milky Way, first made by Frank C. Mars in 1923. A fun twist: in the UK, a bar called Milky Way has no caramel at all, and the bar that's closest to the American Milky Way is sold there as a Mars bar.

• Baby Ruth, first sold in 1921, wraps peanuts, caramel and nougat in chocolate.
• Snickers arrived in 1930. The Snickers Almond swaps the peanuts for almonds.
• The Snickers Peanut Brownie keeps the peanuts and caramel and trades the classic nougat for a brownie one.
• PAYDAY, from 1932, skips the chocolate completely: salted peanuts rolled in caramel around a soft centre.

A crunchy cookie changes the whole bite. Twix, first made in the UK in 1967, lays caramel on a cookie and covers it in milk chocolate. The Cookies & Creme version swaps the caramel for a creme layer with cookie pieces.

Next time you're choosing, it's worth asking yourself one question: chewy, crunchy or smooth? The answer usually picks the bar for you.