Why Is My Brownies Taking So Long to Cook? Here’s What You Need to Know

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If you’ve ever made brownies, you know that they can be a bit finicky when it comes to cooking time. Sometimes, they’re done in just 20 minutes, while other times, it can take 30 minutes or more. What gives? In this article, we’ll explore the science behind brownies and share tips for getting them just right every time.

Understanding the Chemistry Behind Brownies

Before we dive into the factors that affect brownie baking time, let’s first talk about the chemistry of brownies. Brownies are a type of cake, and like all cakes, they rely on a delicate balance of ingredients to turn out perfectly. The flour provides structure, the sugar adds sweetness, and the eggs and butter supply moisture and richness. But it’s the cocoa powder that really sets brownies apart.

Cocoa powder contains natural compounds called flavanols, which react with oxygen during baking to create a chemical reaction known as oxidation. This chemical reaction creates the deep, rich chocolate flavor and fudgy texture that we love in brownies. However, it also means that brownies are more sensitive to changes in environment and baking techniques.

Another important factor in the chemistry of brownies is the leavening agent. Most brownie recipes call for baking powder or baking soda, which help the brownies rise and become fluffy. However, too much leavening agent can cause the brownies to rise too quickly and then collapse, resulting in a dense and dry texture. It’s important to follow the recipe carefully and measure out the leavening agent precisely to achieve the perfect balance of rise and texture in your brownies.

Factors That Affect Brownie Baking Time

Now that we understand the chemistry of brownies, let’s explore the factors that can affect their baking time:

  • Temperature: If your oven temperature is too low, your brownies will take longer to cook. Conversely, if it’s too high, they may cook too quickly and burn
  • Pan Size: The size and material of your baking pan can also affect brownie cooking time. A smaller pan will lead to thicker brownies, which will take longer to cook. Similarly, a non-stick or shiny pan may reflect heat differently than a dark or metal pan.
  • Elevation: If you live in a high-altitude area, the lower air pressure can affect the way your brownies cook. This is because the lower air pressure causes water to boil at a lower temperature, which can lead to longer cooking times.
  • Humidity: Humidity can also affect brownie baking time, as excess moisture in the air can make it harder for the brownies to cook through.

Another factor that can affect brownie baking time is the type of oven you are using. Convection ovens, which circulate hot air, may cook brownies faster than traditional ovens. It’s important to adjust your baking time accordingly if you are using a convection oven.

Tips for Prepping Your Oven for Brownie Baking

Before you start baking brownies, it’s important to make sure your oven is properly prepped to ensure even cooking. Here are some tips:

  • Preheat your oven to the correct temperature according to your recipe. Use an oven thermometer to ensure accuracy.
  • Position your rack in the center of the oven, so the brownies cook evenly.
  • Avoid opening the oven door too often during baking, which can cause fluctuations in temperature and extend cooking time.

Another important tip for prepping your oven for brownie baking is to clean it beforehand. Any leftover food or debris can affect the taste and texture of your brownies. Use a damp cloth to wipe down the inside of your oven, and remove any crumbs or residue from the bottom.

Additionally, consider using a baking stone or sheet to help distribute heat evenly throughout the oven. This can help prevent hot spots and ensure that your brownies cook evenly. Just make sure to preheat the stone or sheet along with your oven.

How to Tell When Brownies Are Done

So how do you know when your brownies are ready to come out of the oven? Unfortunately, there’s no one-size-fits-all answer, as it depends on your recipe, pan size, and oven temperature. However, there are a few general tips you can follow:

  • Check for doneness around the 20-minute mark. Insert a toothpick or cake tester into the center of the brownies. If it comes out with a few moist crumbs attached, they’re done. If it comes out wet, they need more time.
  • Look for a shiny, crackly surface on top of the brownies, which is a sign that they’re done.

Another way to tell if your brownies are done is to gently press the top with your finger. If it feels firm and springs back, they’re likely done. If it feels soft and leaves an indentation, they need more time in the oven. Keep in mind that brownies will continue to cook and set as they cool, so it’s better to slightly underbake them than to overbake and end up with dry, crumbly brownies.

Testing Brownies for Doneness: Methods and Tools

If you’re having trouble gauging when your brownies are done, here are a few more methods you can try:

  • Press lightly on the center of the brownies with your finger. They should be firm and spring back.
  • Use a meat thermometer to measure the internal temperature of the brownies. It should be around 190 degrees Fahrenheit when fully cooked.

Another method to test if your brownies are done is to insert a toothpick into the center of the brownies. If it comes out clean, without any batter sticking to it, then your brownies are fully cooked. Additionally, you can also look for the edges of the brownies to be slightly pulled away from the sides of the pan, which is another indication that they are done.

Common Mistakes That Affect Brownie Texture and Cook Time

Even with the best of intentions, it’s easy to make mistakes when baking brownies. Here are a few common culprits that can affect their texture and cook time:

  • Overmixing the batter, which can lead to tough, chewy brownies
  • Using a pan that’s too big or too small
  • Not measuring ingredients accurately
  • Forgetting to grease the pan, which can cause the brownies to stick and cook unevenly

Another common mistake that can affect brownie texture and cook time is overbaking. It’s important to keep a close eye on your brownies while they’re in the oven, as they can quickly go from perfectly fudgy to dry and crumbly. To avoid overbaking, set a timer for the minimum recommended cook time and check the brownies with a toothpick or cake tester. If it comes out with a few moist crumbs attached, they’re done. If it comes out completely clean, they may be overbaked.

Adjusting Your Recipe to Achieve Perfectly Baked Brownies Every Time

If you’ve tried all of these tips and still can’t seem to get your brownies just right, it may be time to adjust your recipe. Here are a few tweaks you can make:

  • Reduce the flour for a fudgier texture
  • Use extra eggs or egg yolks for added moisture
  • Adjust the sugar or cocoa powder for a sweeter or more chocolatey flavor
  • Experiment with different types of fats, such as oil or melted butter, for a different texture

Another factor to consider when adjusting your brownie recipe is the baking time and temperature. If your brownies are coming out too dry or overcooked, try reducing the baking time or lowering the oven temperature slightly. On the other hand, if your brownies are too gooey or undercooked, increase the baking time or raise the oven temperature a bit. Remember to keep an eye on your brownies as they bake and use a toothpick or cake tester to check for doneness.

How Humidity and Altitude Affect Brownie Baking Time

Earlier, we mentioned that altitude and humidity can affect brownie baking time. If you live in a high-altitude or humid area, here are a few additional tips to keep in mind:

  • Reduce the baking powder or baking soda in your recipe, as they can cause the brownies to rise too much and then collapse.
  • Increase the oven temperature slightly, as the lower air pressure may affect heat distribution.
  • Add a bit of extra liquid to the recipe to counteract the dry air. This could be water, milk, or even coffee.

Quick Fixes for Undercooked or Overcooked Brownies

Finally, let’s say you’ve baked your brownies and they’re still not quite right. Here are a few quick fixes:

  • If your brownies are undercooked, put them back in the oven for a few more minutes. Keep an eye on them to make sure they don’t burn.
  • If your brownies are overcooked and dry, try brushing them with a simple syrup made from equal parts sugar and water. This will add moisture and sweetness.


So there you have it. Brownies may seem simple on the surface, but they’re actually quite complex when it comes to baking. By keeping these tips and tricks in mind, you should be able to achieve perfectly baked brownies every time.