How to Make Brittle

Caramelizing is the process of cooking sugar until it browns. When table sugar is heated to high temperatures (about 340°F), it melts and darkens. As it turns from clear to dark amber, the sugar undergoes chemical changes. The sugars break apart and reform new compounds. Caramelizing not only makes foods rich and dark in color but also enhances the taste. Cooking sugar until it melts and becomes a rich amber color creates complex flavors and aromas ranging from nutty and toasty to fruity and mildly bitter. When cooled, the liquefied sugar hardens into a glasslike solid candy. Cooking can also "caramelize" the natural sugars in fruits and vegetables.

Combine sugar, water, and lemon juice in a heavy saucepan over medium-high. Adding a little water (as opposed to melting dry sugar) gives the sugar time to develop caramel flavors and facilitates even browning. Brush sides of pan with a wet pastry brush to release any sugar crystals that might cling to the pan; this prevents a chain reaction of more crystals re-forming. Acidic lemon juice also inhibits crystallization.

Boil, without stirring, until amber-colored and a candy thermometer registers 310°F. After it gets to 300°F, sugar has reached the stage at which it will form into hard candy once cooled. As it continues to cook to 310°F, the sugar caramelizes and develops rich flavors. The sugar does continue to brown in the hot pan after coming off the heat, so pour it quickly onto the nuts.

Have a jelly-roll pan ready, lined with parchment paper coated with cooking spray and sprinkled evenly with nuts and seeds. When the melted sugar cools and hardens, it will adhere to most surfaces—but it does release easily from parchment paper. Oil (from cooking spray) adds another layer of nonstick protection, both on the parchment paper and on the spatula used for spreading the caramelized sugar.

Work quickly to spread sugar syrup into a thin layer over the nuts and seeds. Cool completely (about 1 hour), and break brittle into pieces. The brittle is susceptible to moisture, which can make it tacky, so wrap it up in parchment paper and pack into an airtight container. If sharing as a gift, add a note to the recipient to store the container in a cool, dry place for up to one week.

This brittle is sweet and mildly bitter all at once—owing to the caramel flavor of the cooked sugar. We added everything you’d find on the iconic bagel of the same name except garlic and onion flakes for a nutty-savory-sweet treat. Brittle is very susceptible to moisture, so wrap it up in parchment paper and pack into an airtight container. Store the container in a cool, dry place. This is a decidedly grown-up sweet treat, but you can make it kid-friendly by omitting the poppy seeds and black sesame seeds and stirring in a teaspoon of ground cinnamon.