What Is Caster Sugar? - Bob's Red Mill Blog
What Is Caster Sugar?

What Is Caster Sugar?

If you bake regularly, you have probably come across a few different types of sugar in your day. The go-tos, like confectioners and granular sugar, are all fairly familiar, but there are a few that you may not have heard of or used before.

With so many different types of sugar on the market, it can be hard to know which one is best for your baking recipe. From brown sugar to fine sugar to icing sugar, is it all really that different from normal sugar? The experts at Bob's Red Mill are here to tell you they are.

One that we have seen in many different recipes in the Bob’s Red Mill kitchen is caster sugar. Our first thought was “what the heck is caster sugar?” but after a little research, we have come to love it! Though caster sugar is tougher to find in certain countries, you can use some helpful tricks to mimic its properties or create your own if you cannot find caster sugar in your local stores. Keep reading to learn all about caster sugar and when we love to use it!

What Is Caster Sugar?

The toughest part about figuring out caster sugar is that it has several different names. Caster sugar is also known as castor sugar, superfine sugar, or even baker’s sugar. This is not to be confused with another sugar you may have used, which also has a few different names: powdered sugar, also known as icing sugar or confectioners sugar. Powdered sugar is ground into such a fine grain that you can barely see the individual grains with the naked eye. Superfine or caster sugar, on the other hand, is still granular sugar, just a smaller grain than your typical sugar. Think of caster sugar as the medium point between your normal sugar and your powdered sugar.

Where Can I Find Caster Sugar?

You might be wondering why you have not heard of caster sugar before, especially if you are a regular baker. The reason for this is that caster sugar is not very commonly used in the United States. While it is used regularly in England for cakes and cookies, caster sugar is a lot tougher to locate in the United States. You will likely need to visit a specialty foods store to find caster sugar, or if you have time, you can always purchase it online. The price tag may be a little shocking, though: caster sugar is a good bit more than you are used to spending on sugar. Never fear, though, if you cannot find caster sugar. There are a couple ways to make your own caster sugar at home! We will discuss those in a few!

So Does It Matter?

The question then is, why is caster sugar even a thing? Can we not get by with just powdered sugar and standard granulated sugar? The basic answer is “maybe,” and it will of course depend on what kind of baker you are and what you need it for. There are differences in how caster sugar and regular sugar react to temperatures and other ingredients, though. Since baking is a science, even something as seemingly unnoticeable as the size of your sugar grains can make a big difference in your end result. Cookies made with caster sugar in certain recipes can be softer, lighter, and have a more buttery flavor to them than those made with regular sugar. It all depends on the recipe, of course, but we find that if a recipe calls for caster sugar, it is best to use caster sugar for the top results.

Substitutes for the Effects of Caster Sugar

If you simply do not have or cannot find caster sugar, then there are few ways that you can substitute it, make your own, or even mimic the effects of caster sugar without even using it. For one, you can use colder, firmer butter when you are creaming it together with sugar. While butter can get greasy if you cream it with sugar for too long, firmer butter will give you a little more time to cream it with the sugar, which will allow the sugar grains to break down a little further, much like caster sugar. A similar effect can be achieved if you whisk your egg whites on a lower speed, for something like a meringue, for instance. This gives the sugar more time to break down naturally. If you are substituting regular sugar for caster, then your end result may just be a bit grainier than you like. If this is not the end of the world for you (say in a cookie, for instance) then you should be all right. Just add in the same amount of regular sugar as the recipe calls for. Try the above tricks to help mimic the breakdown of the sugar granules a little further!

Making Your Own Caster Sugar

Of course, as we mentioned, you can always make your own caster sugar if you prefer! This is fairly simple to do: just add your regular white sugar to a food processor and process it. A couple small tips, though. First, add a little extra sugar to account for the amount that may stay in the processor or be processed into dust. You also should keep a kitchen towel over the lid of the processor, so as to trap that dust inside a little better. Even with the lid on, the particles can spread all over the place, yikes! Keep an eye on your regular white sugar as it processes: we recommend about 1-2 minutes for this, but if you process it too long then you may accidentally make powdered sugar, in which case you will have to start over! It is worth noting that the granules will be slightly less uniform than if you purchased caster sugar directly, so this is not a solution to use 100% of the time, but it should work fairly well in a pinch! Specifically with meringues and souffles, you probably want to stick to caster sugar if at all possible, but in other recipes a good DIY is always a handy option to have around!

Some Caster Sugar Recipes to Try Out

If you did not come here with a baking recipe in mind but now you're excited to try out some caster sugar, you're in luck! These are a couple of our favorite dessert recipes, all using superfine or caster sugar. Try making your own for some of the recipes below if you cannot locate caster sugar in your local store! Try them all out and submit your own recipes to be featured on Bob's Red Mill!

White Chocolate and Raspberry Creme Brulee

Creme brulee is one of our favorite desserts--creamy and delicious, with that perfectly crisp crust on the top! The caster sugar allows this mixture to remain smooth instead of getting granular, which you especially do not want in the crispy layer overtop. You can try it with any number of berries or other flavors if you prefer, but make sure you use a mild chocolate, to avoid getting a bitter flavor! This recipe is simple and offers a lot of variety to impress all of your favorite guests!

Apple and Almond Cake Recipe

This cake is one of those cakes that you can almost call a “healthy snack” or even eat for breakfast if you really wanted to . . . and trust me, you will really want to. It replaces flour with ground almonds, and there is not one drop of butter in it, so if you are dairy free then this cake is perfect for you (it is unfortunately not vegan, though, because of the eggs). This is a perfect transition sweet for your new healthy lifestyle in 2018, and your kids will not even notice that they are eating tons of fruit in the process!

Lemon Meringue

Reader, beware! This caster sugar recipe is not for the faint of heart. We mentioned how caster sugar is perfect for meringues, and this one is no exception. The layers of delicious meringue, whipped cream, pistachio, and white chocolate will get you first prize at your holiday dinner! You will have to work for it, though, as these meringue layers take a little extra love and attention. You will want to drain your yogurt overnight in a wire mesh strainer in the fridge, so make sure you plan ahead to create this masterpiece. If you think you can take it on, we promise that each decadent, lemon-y bite will be a perfect reward for all your hard work! And you totally do not have to share if you do not want to . . . 

Okay, most of you have probably quit reading to go buy or make some caster sugar of your own by now. Though it may not seem like a serious distinction, the grain size of these different types of sugar can make a huge difference in the makeup of your end product, whether that is a yummy cake or a towering pile of meringue heaven. Test out making your own or purchasing some and let us know what you think of caster sugar!

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  1. Cathie
    What about C&H super fine sugar for quick dissolving ? Is this simular to caster sugar?
    1. Betsy Birdsall
      It IS caster sugar. Same thing. Baker's sugar.
  2. Rick
    I found a Recipe that calls for caster sugar in ice cream mixed with eggs and milk and heated on the stove. Would not regular sugar work since they both should melt?
    1. Whitney Barnes
      Hi Rick - Yes, you're correct. Regular cane sugar would work as a substitute in that type of recipe.
  3. Betsy Birdsall
    C&H manufactures and sells "Baker's Sugar" in the U.S. It is caster sugar, sold under a different name. It is sold in most major supermarkets.
    1. Sue
      Yes, See earlier reply about this same question.
  4. Todd Rose
    I came across a baking recipe that called for moscovado sugar. Is this just another term for brown sugar? What's the story?
    1. Whitney Barnes
      Whitney Barnes
      Hi Todd, muscovado sugar is unrefined cane sugar in which the molasses isn't removed. It has a very sticky and moist texture in comparison to brown sugar. Brown Sugar, on the other hand, is typically white sugar with molasses added back in.
  5. Niki Renner
    Why doesn’t Bob’s red mill make a caster sugar?
    1. Whitney Barnes
      It's not something in our current product line up but our Cane Sugar is very similar. We'll pass along your feedback to our team here.
  6. m joyce
    Do you have a caster/confectioner ground sugar that has not been refined with bone meal. I am thinking a vegan friendly caster sugar.
    1. Whitney Barnes
      Hi! We don't carry any powdered/confectioner sugar. Our Sparkling Sugar is vegan, however; you could pulse it in a food processor to make a texture very similar to caster sugar - just check the tips in the blog post above :)
  7. Michele
    I just grind granulated sugar with a mortar and pestle. It doesn't take that long.
  8. Rani
    Just made Caster sugar for dusting on a batch of candied grapefruit rinds. I prefer the finer sugar so that there aren't any granules to crunch.
  9. Jim Houghton
    Powdered sugar usually contains a small amount of something -- corn starch? -- to keep it from clumping up. Does Caster Sugar contain anything but just cane sugar?
  10. Denver
    Just a note that if you run sugar through your really nice food processor, it may scratch the plastic bowl, making it cloudy.
  11. Doug Shaw
    What you are calling Caster sugar is called Berry Sugar in Canada .
  12. Chris Stark
    A few years ago, I bought a 28 oz bag of Bob’s Red Mill Decorative Sparkling Sugar, which I have used for many batches of cookies, cakes, and puddings. I am down to my last tablespoon or two, and want more, but it’s not listed on your website. Don’t you have it anymore? I need it! I want it! I gotta, gotta, have it! OOoo! Sounds like a song….never mind, I digress. Sparkling sugar….don’t you sell it anymore?
    1. Whitney Barnes
      Hi Chris - Unfortunately that product has been discontinued.

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