What is the Difference Between Granulated, Light Brown, and Dark Brown Sugar?

I’ve been doing a lot of baking in the past few weeks. And that brought to mind a question I’ve always wondered about – what’s the difference between granulated, light brown, and dark brown sugar? Being naturally inquisitive, that question led to others:

• When to use granulated vs brown sugar?
• Can you substitute light brown for dark brown sugar (and vice versa) at will?
• Can you make DIY brown sugar at home?

After searching through books and websites by cookbook authors, food chemists, and chefs I respect, here is what I learned about granulated, light brown, and dark brown sugar.

What is the difference between white and brown sugar?

Granulated sugar is the most refined form of sugar. Regardless of the size of the sugar crystals (the difference between “regular” white, fruit sugar, and superfine or bar sugar), it is just sucrose. 

Brown sugar is sugar that either has not had all of the molasses removed, or that has had it removed and returned back into the sugar. (Molasses is a byproduct of the sugar refining process.) Shirley Corriher, in her book Bakewise, explains that sugar processors call the process of returning molasses into refined sugar as “painting” the refined sugar. 

What is the difference between light brown and dark brown sugar?

Simply put, dark brown sugar contains more molasses than light brown sugar. How much more? I only found one source that provides specific measurements of the difference – Rose Levy Berenbaum. On her website, Real Baking with Rose, Berenbaum says that light brown sugar contains 3.5% molasses, while dark brown contains 6.5% molasses. 

When to use granulated vs. brown sugar?

I think of white and brown sugar as cousins. They have some genes in common, but they can be very different in how they act and react.

Flavor-wise, white sugar is purely sweet – no overtones or other flavors. Brown sugar, on the other hand, is a bit acidic, with all the complexity that molasses adds. Brown sugar can add a layer of flavor, especially in fruit desserts such as galettes or crumbles and crisps. It’s also a common ingredient in barbecue sauce and sweet toppings, such as rum glaze rum glaze for grilled fruit. 

White and brown sugar act differently in cookie or cake batter.

Many cookie and cake recipes use a leavening agent – either baking soda or baking powder – to make the cookies or cake rise. Baking soda (sodium bicarbonate) requires acid in order to create a leavening or rising action. Brown sugar has an acidic component – in the molasses. Because it already contains acid you can use brown sugar with baking soda to produce a leavening or rising reaction. White sugar, on the other hand, does not have an acidic component. In order to get cookies or cake to rise with a leavening agent when the sweetener is white sugar, you either have to add another acidic ingredient (such as lemon juice or yogurt) or use baking powder, which already contains acid. See Elise Bauer’s excellent explanation of the difference between baking soda and baking powder.

Another way to make cookies and cakes rise is through creaming the sugar with butter. Beating them together for several minutes creates air bubbles, and that, in turn, makes the batter lighter and higher when it bakes. White sugar is lighter than brown. The molasses in brown sugar makes it denser, heavier, and moister than white sugar. That difference means that white sugar creates an airier batter in recipes that call for creaming the sugar with butter. 

In baking you can use either white and brown sugar, or combine them, if you understand how they act differently. Stella Parks, one of my go-to sources for baking information and recipes, has an excellent explanation of how granulated and brown sugars act in cookies. 

Substituting light for dark brown sugar (or vice versa).

Rose Levy Berenbaum advises that if a recipe does not specify which to use, you should go with light brown sugar.  I like the richer taste of dark brown sugar. However, I recognize that it can become overwhelming in a cookie or cake with other flavors. Therefore, sometimes I mix the two, or simply add a bit of dark brown sugar with a larger amount of light brown. 

Serious Eats did an interesting side-by-side comparison of light and brown sugar in cookies.

How to make DIY brown sugar?

In The Baking Bible, Berenbaum gives proportions of granulated sugar and molasses, which if combined yield light brown or dark brown sugar. She specifies 1 cup of white sugar (7 ounces/200 grams) plus 1/4 cup (59 ml) light molasses for light brown sugar or 1/2 cup (118 ml) light molasses for dark brown sugar. I haven’t tried those DIY recipes and compared them to store-bought brown sugar, but she is a noted baking expert and I love her book, so I trust that they work. 

And now, a bonus tip:

What to do if your brown sugar hardens?

Even if kept in an air tight container, brown sugar can harden. I keep mine in the refrigerator, which does help retain its moisture. Still, brown sugar can get hard, especially dark brown sugar. 

There are a variety of ways to soften it. For immediate use, I usually go for the quickest method: microwaving it. The brown sugar will harden again once it stands after microwaving, so you have to use it relatively quickly. Another way to soften it overnight in a tightly closed container by adding a piece of damp towel, a slice of fresh bread, or a slice of apple on top of the brown sugar.