Saltine cracker toffee, or Christmas crack, is a popular holiday treat. It’s a layer of saltine crackers coated in toffee topped with chocolate and sometimes with nuts. I enjoyed the rich, buttery taste, but I’d double the layer of saltines and use dark chocolate in an effort to cut the sweetness of the toffee. Even so, I could only take so much. In this version, I added miso for a salty note that elevates the toffee and complements the chocolate. I can’t get enough of it! As always, I’ll share the recipe and then talk science. You can also watch me make this recipe on YouTube!
Miso Saltine Toffee
Makes 1 10 × 15-inch (25 × 38-cm) sheet
The holiday classic, saltine toffee, is elevated with a touch of miso paste. The miso adds a salty note that complements both the toffee and the chocolate for a rich, complex taste.
- 40 saltine crackers (or enough to line your pan)
- 1 c (2 sticks, 227g) butter
- 1 c (220g) brown sugar
- 2 Tbsp (35g) shiro miso
- 2 c (340g) semisweet chocolate chips
- Preheat oven to 400°F (200°C). Line a 10 × 15-inch (25 × 38-cm) rimmed baking sheet (jelly roll pan) with foil and spray with nonstick cooking spray. Spread saltines in a single layer across the sheet.
- In a saucepan, heat the butter and sugar over low heat, stirring until the sugar dissolves and the mixture is boiling. Alternatively, heat the butter and sugar on low power in the microwave, stirring every 15–30 seconds, until the sugar dissolves and the mixture is boiling, about 1 minute. Remove from heat and whisk in the miso until smooth.
- Pour the mixture over the saltines and spread it to the edges. Quickly place the baking sheet in the oven. Bake for about 8–9 minutes or until dark amber in color. The toffee will bubble. Watch it closely to make sure it doesn’t burn.
- Sprinkle chocolate chips over the saltines and return them to the oven for 10 seconds to melt the chocolate. Spread the chocolate evenly over the saltines.
- Leave the toffee to cool, then break or slice into pieces. Store in an airtight container.
Miso is a Japanese seasoning.
Before we get into the science of this recipe, let’s talk about miso, which may be an unfamiliar ingredient. In the U.S., you can find it in Asian grocery stores or in the international aisles of supermarkets. Miso is gaining recognition in Western cultures—you’ve probably had miso soup—but what exactly is it?
Miso is a Japanese seasoning that’s made from fermented soybeans. The soybeans are cooked, then mixed with water, salt, and a starter called kōji, which contains the fungus that ferments the soybeans. (Remember, during fermentation, microorganisms eat sugars and produce the compounds that flavor a food.) Depending on the type of miso, the mixture might also include grains such as rice and barley. The shiro miso in this recipe, for example, is fermented with rice. The length of the fermentation also varies, and it determines the miso’s depth of flavor and color. Shiro miso is not fermented for very long, so the flavor is mild and the color is light compared to other varieties. It’s also slightly sweet because the fungus didn’t eat all of the sugar.
In Japan today, there are hundreds of varieties of miso, and it’s widely used to season soups and other traditional foods. However, when miso was introduced to Japan by China in the 7th century, it was a luxury that was only accessible to the rich. The paste was eaten directly or used as a condiment. Over time, however, commoners began to make miso and it became more widely available. From the 15th to 19th centuries, through civil war and frugal lifestyles, miso was an important component of the Japanese diet. Rice and miso soup was a typical breakfast, and it’s still the picture of traditional home cooking.
The refinement of miso production was spurred by its crucial role as a source of nutrition. Its development was also fueled by the richer merchant class that emerged in the 17th to 19th centuries, which wanted higher-grade misos. Today, more than 1300 types of miso are made throughout Japan using different ingredients, vessels, and fermentation conditions that are unique to each region. And with the advent of globalization, miso is now exported worldwide.
As miso has made its way across the world, chefs have started incorporating it into Western dishes and desserts to add flavor to everything from meats to brownies. In Western desserts, miso is often paired with chocolate and caramel flavors, like in this saltine toffee. Now that we know a little more about miso, let’s examine the remaining components of this recipe.
Baking the saltines
Most toffee and brittle recipes don’t use the oven. Instead, you cook the sugar and butter until it reaches the right color and temperature, pour it onto a sheet, and let it cool. Why is this recipe different?
The first time I tested this recipe, I poured the hot toffee onto two batches of saltines and only baked one of them. As you can see below, the most striking visual difference is that the toffee encases the baked saltines while it merely sits on top of the unbaked ones. (The lumps are miso, which I hadn’t yet learned to whisk in.) The unbaked toffee was a little chewier, which wasn’t surprising because it didn’t cook as long. It contained more water, and candies made from less concentrated sugar syrups are softer and chewier. But that could always be adjusted by cooking the toffee longer on the stove.
The difference that justified the use of the oven was the texture of the saltines. Notice how wet the unbaked saltines look. The grease from the toffee soaked right into them. The baked saltines, however, are dry and crisp. The fat soaked into these saltines, but then it puffed them in the heat of the oven, leaving them dry and crisp. (We’ll cover this in more detail in the next set of posts about leavening). The same thing happens in fire crackers, except the fat for those comes from the cheese.
For this recipe, then, we start to heat the butter and sugar on the stove top or in the microwave to homogenize the mixture and start boiling off some water. Then we move it to the oven, where the toffee crisps the saltines as it finishes cooking. Because we cannot use a thermometer to gauge the progress of the sugar syrup, we go by color. The miso makes this toffee burn more easily (I know from experience!), so keep an eye on it the first time you try this recipe. There is no harm in removing the saltines a little early—they’ll be a little chewier, but delicious nonetheless!
Toffee is a sugar syrup cooked to the hard crack stage, and like any candy made from syrup, we don’t want it to crystallize while it cooks. This recipe prevents crystallization in several ways, which makes it possible to whisk in the miso. Usually, stirring and agitation crystallize sugar. To learn more about sugar crystallization in candies, check out the last post.
First, the miso is added while the mixture is hot before too much water has boiled off. Both of these factors encourage the sugar to remain dissolved. Second, the recipe contains a lot of butter. The fat coats any sugar crystals that might form and separates them from other sugar molecules that might want to attach to the crystal and make it larger. This recipe also uses brown sugar, which is slightly acidic. With heat, acids break sucrose down into fructose and glucose, which interfere with sucrose crystallization. These factors make the toffee quite resistant to crystallization, so we can whisk in the miso, pour it over our saltines, and spread it around with no fear of crystallization.
Miso makes a delightful version of the classic saltine toffee that’s sweet, salty, and crunchy. The butter and brown sugar prevent the sugar from crystallizing as the candy cooks, making this a no-fuss recipe. I hope you give it a try!
Corriher, S. O. Bakewise; Scribner: New York, 2008.
Corriher, S. O. Cookwise; William Morrow and Company, Inc.: New York, 1997.
Figoni, P. How Baking Works, 3rd ed.; John Wiley & Sons, Inc.: Hoboken, 2011.
Miso. Japanese Miso Promotion Board, 2012.
Miso. Wikipedia, 2020.