Learn the science behind:
Wondering why some cookies, such a Melting Moments, just seem to melt in your mouth? They’re delicate and only just hold together before they crumble apart once you bite into them. By simply choosing the right ingredients you can make them too.
The secret? Using corn starch and icing sugar instead of regular white sugar.
- Melting moments are melt-in-your-mouth cookies
- Optimizing a melt-in-your-mouth cookie
Melting moments are melt-in-your-mouth cookies
Often called ‘melting moments’, these melt-in-your-mouth cookies literally melt in your mouth. They’re delicate and slightly crispy, but fall apart in your mouth easily. At first sight, they look very similar to your regular shortbread cookie. However, they’re noticeably more delicate. A quick look at the recipe shows that they’re different in two key areas: the use of corn starch and icing sugar.
Corn starch in cookies makes them ‘sandy’
The dough for making melting moments contains corn starch alongside plain wheat flour. Instead of corn starch, you could also use potato starch, which will work in a similar way.
Corn starch is made up of 100% starch, a large carbohydrate. Starches are great at thickening liquids, however, can’t make a strong network to hold a cookie together. It makes them great for a melt-away cookie.
But, don’t be tempted to replace all of the wheat flour with corn starch! Corn starch by itself isn’t strong enough to hold the cookie together. You’ll end up with a too delicate cookie, that doesn’t hold up, as you can see in the photo below.
This isn’t unique for corn starch, the same will happen when using other pure starches such as potato starch. Whereas corn starch is made up of almost 100% starch, wheat flour also contains proteins, a little bit of fat even and some other types of carbohydrates. These help to keep a cookie together.
Icing sugar helps cookies melt in your mouth
Cornstarch is the first key to unlocking these cookies, but, don’t underestimate the importance of using icing (aka powdered) sugar. Chemically speaking icing sugar is the exact same ingredient as white sugar, or granulated sugar. The only difference is the particle size. Icing sugar consists of tiny, very fine sugar crystals. You can no longer see the individual crystals, it has become a smooth soft powder.
Melting moments contain very little water. The only water they contain comes from the butter. As such, most of the sugar in the cookie dough won’t actually dissolve. It will remain as is within the cookie. If you use regular sugar, that means you end up with large rough sugar crystals in your cookie. This diminishes the melt-in-your-mouth effect. Icing sugar on the other hand only strengthens this effect. The icing sugar crystals literally immediately melt in your mouth when you eat the cookie!
Want to test this out? Simply put a little bit of regular sugar on your tongue and feel how it tastes and dissolves. Then, do the same with some powdered sugar. Notice the difference?
Optimizing a melt-in-your-mouth cookie
- icing sugar
- corn starch
- all-purpose flour
Note, vanilla is added for flavor, but won’t do much else than just that. You can leave it out without impacting texture!
If your melting moment didn’t turn out as you hoped for, you can optimize it quite easily. Tweak the ratio of ingredients, to make it to your liking.
Reduce spreading by reducing butter
The only source of fat and moisture in these cornstarch cookies is butter. All the other ingredients are dry. Leaving out butter would leave us with a pile of powders, not a cookie. The butter is what keeps all ingredients together and ensures the starches can cook properly. As such, butter has a crucial structural role.
Butter is solid in the fridge, soft at room temperature, but will turn completely liquid in a hot oven. If a cookie contains too much butter, this will cause the cookie spread a lot in the oven. Your cookie dough may seem firm, but once in the oven it can turn so soft that it can no longer hold its shape. If this happens, simply reduce the amount of butter in your recipe.
Reduce cracking by increasing butter
The opposite is true as well. If your cookies are too firm, or even crack, they do not contain enough butter. Simply increase the amount of butter to fix it.
Reduce stickiness by reducing butter
If your recipe calls for indenting the tops of your cookies with a form or other type of pattern, you may find that the dough is too sticky to do so. The fork will stick to the dough and you can’t properly remove the fork without somewhat ruining the pattern. Again, adjusting the amount of butter is the way to go. Slightly reduce the amount of butter to reduce stickiness and make placing an imprint easier.
Increase sandiness by increasing corn starch content
These cookies are delicate, almost sandy, melt-in-the-mouth due to the presence of corn starch. If the cookies still feel too firm and not ‘sandy’ enough, increase the amount of corn starch. Make sure to simultaneously decrease the amount of flour, or your cookie as a whole will become too dry and firm.
Increase sweetness by increasing icing sugar
You could technically make these cookies without sugar. However, they’d be very bland. Sugar adds sweetness, but also a little bit of crispiness. Only change the amount of sugar if you’re not happy with the overall sweetness and flavor profile of the cookie. Sugar plays a role in the structure, but that is easier to adjust with the other ingredients.
If you add a lot more icing sugar, keep in mind that you might need to slightly reduce the amount of flour and starch. Sugar binds water, leaving less for the other ingredients, which can make the dough too dry.