Pan Size Switch: Doubling 9X13 Recipes

Doubling a 9x13 recipe to fit a larger pan can be tricky, but with a little bit of math, it's possible! The key is to calculate the surface area of the original pan and the new pan, and then adjust the recipe accordingly. For example, if you want to double a recipe that calls for a 9x13 pan, you would need to use a pan with twice the surface area, such as a 13x18 pan. However, it's important to consider the depth of the pans as well, as this will affect the total volume of the recipe. If the new pan is taller than the original pan, you may need to adjust the recipe further to account for the extra space.

Doubling a 9x13 recipe for a 13x18 pan

To calculate the correct amount of ingredients for your doubled recipe, you need to calculate the volume of your 9x13 pan and your 13x18 pan. If your 9x13 pan is 2 inches tall, its volume is 9x13x2 = 234 cubic inches. If your 13x18 pan is 1 inch tall, its volume is 13x18x1 = 234 cubic inches. So, in this case, the 13x18 pan is the same volume as the 9x13 pan, and you would need to multiply all the ingredients in your 9x13 recipe by 2 to fill the 13x18 pan.

However, if your 9x13 pan is also 1 inch tall, its volume is 9x13x1 = 117 cubic inches. In this case, the 13x18 pan is almost twice the volume of the 9x13 pan, so you would need to multiply all the ingredients in your 9x13 recipe by 1.5 to fill the 13x18 pan.

If you don't want to calculate volumes, you can also calculate the surface area of the base of your pans. The surface area of a 9x13 pan is 9x13 = 117 square inches. The surface area of a 13x18 pan is 13x18 = 234 square inches. So, the 13x18 pan is almost exactly twice the surface area of the 9x13 pan, and you would need to multiply all the ingredients in your 9x13 recipe by 1.5 to fill the 13x18 pan.

If you want to be precise, it's best to calculate the volume of your pans and adjust your recipe based on that. But if you don't know the height of your pans, calculating the surface area of the base is a good alternative method.

Rounding up or down

When doubling a 9x13 recipe, you'll need to use a pan with double the area of a 9x13 pan, which is 234 square inches. This is the area of a half-sheet pan, which is 13x18 inches.

However, as the sides of a half-sheet pan are only 1" tall compared to the 2" tall sides of a 9x13 pan, you will need to also take volume into account. This means that doubling a 9x13 recipe will likely overflow a half-sheet pan.

To avoid this, you can use a larger pan or adjust your recipe. For example, you could use a 12x18 sheet-cake pan, which is 2" tall, or a quarter sheet pan, which is 13x18 inches and 2" tall. Alternatively, you could multiply your 9x13 recipe by 1.5, which will give you enough batter for a half-sheet pan without overflowing.

When adjusting your recipe to fit a different pan size, don't be afraid to round up or down. As long as you apply the same rounding to all ingredients in the recipe, you'll end up with the same result, just slightly taller or thinner.

For example, if you need to multiply your recipe by 1.44, you could round this up to 1.5 to make your life easier. This will result in slightly taller brownies or cake. On the other hand, if you need to multiply by 1.26, you could round this down to 1, resulting in slightly thinner treats.

It's important to note that you shouldn't fill your pans more than about 2/3 full, as this may cause the batter to overflow. If you end up with too much batter, you can always scrape the excess into cupcake molds or a mini cake pan.

Additionally, when increasing the recipe and using a larger pan, you should anticipate a longer baking time. Conversely, when decreasing the recipe and using a smaller pan, check on your bake earlier than you think you need to. Always use a cake tester or look for the visual cues in the recipe, such as a golden brown colour or springiness when pressed, to determine if your bake is ready.

Baking time adjustments

When doubling a 9x13 recipe, the baking time will need to be adjusted depending on the size of the new pan.

If you are using a pan with a similar surface area, such as a 13x9 pan, the baking time should remain roughly the same. However, if you are using a larger pan, such as a half-sheet pan (13x18), the baking time may need to be increased. This is because a larger pan will result in thinner layers, which may require a longer baking time.

On the other hand, if you are using a smaller pan, such as an 8x8 or 9x9 pan, the baking time may need to be decreased. This is because a smaller pan will result in thicker layers, which may bake more quickly.

It's important to keep an eye on your bake and use a cake tester or toothpick to check if it is ready. You may also need to adjust the oven temperature to ensure even baking.

Additionally, the depth of the pan can impact baking time. If you are using a pan with a shallower depth, such as a half-sheet pan with 1-inch sides, the batter may overflow or bake more quickly. In this case, you may need to reduce the oven temperature or bake in a convection oven to prevent overbrowning.

When doubling a recipe, it's always better to have a little extra batter than not enough. You can use any remaining batter to bake a few cupcakes or make some cakelets.

Using a scale

Doubling a 9x13 recipe requires some calculations and adjustments to ensure the final product turns out as expected. Here are some detailed instructions on using a scale to achieve this:

Understanding Pan Sizes and Scaling:

Before doubling a recipe, it's important to understand the concept of pan sizes and scaling. The size of a pan is typically described by its dimensions, such as 9x13 or 8x8. These dimensions refer to the length and width of the pan, and they determine the surface area of the pan's bottom.

Calculating Surface Area:

To double a 9x13 recipe, you need to calculate the surface area of the 9x13 pan and then find a larger pan with approximately double the surface area. The surface area of a rectangular pan, such as a 9x13, can be calculated by multiplying the length and width together. So, for a 9x13 pan, the surface area is 9 x 13 = 117 square inches.

Choosing the Right Pan for Doubling:

To double the recipe, you'll need a pan with roughly double the surface area of the 9x13 pan. A 13x18 half-sheet pan has a surface area of 234 square inches, which is indeed double that of the 9x13 pan. Therefore, a 13x18 half-sheet pan is an appropriate choice for doubling the recipe.

Adjusting the Recipe with a Scale:

When doubling a recipe, you need to adjust the quantities of all the ingredients accordingly. This is where a scale comes in handy. Here's a general guide:

• Weigh each ingredient in the original recipe: Start by weighing each ingredient specified in the original 9x13 recipe using your kitchen scale. Make sure to use the same units of measurement (e.g., grams or ounces) consistently throughout.
• Calculate the required weight for doubling: Since you are doubling the recipe, you will need twice the amount of each ingredient. Multiply the weight of each ingredient by 2 to determine the new weight required for the doubled recipe.
• Weigh out the doubled quantities: Using your scale, measure out the new, doubled quantities for each ingredient. For example, if the original recipe calls for 200 grams of flour, you will now need 400 grams for the doubled recipe.
• Prepare the doubled recipe: Follow the same preparation and baking instructions as the original recipe, but use the doubled quantities of ingredients. Keep in mind that baking times and temperatures may need slight adjustments due to the larger volume of the recipe.

Tips and Considerations:

• Always use the same units of measurement (metric or imperial) consistently throughout your calculations to avoid confusion.
• When doubling a recipe, pay close attention to ingredients that are measured in smaller quantities, such as teaspoons or tablespoons. You may need to convert these measurements to grams or ounces for accurate doubling.
• Some ingredients, like eggs, can be tricky to double precisely. In such cases, it's generally acceptable to round to the nearest whole number. For example, if the original recipe calls for 2 eggs, use 4 eggs in the doubled recipe.
• Keep in mind that not all ingredients scale linearly. For example, leavening agents like baking powder or baking soda may need to be adjusted slightly when doubling a recipe to ensure the final product rises properly.
• Always refer to the original recipe's visual cues for doneness, such as browning, cracking, or a toothpick inserted into the centre coming out clean. These cues are often more reliable than bake times, especially when dealing with larger quantities of batter.

Partial ingredients

Another option is to calculate the amount of eggs needed based on the weight of the other ingredients. Weigh the total amount of dry ingredients in your original recipe, then weigh the eggs you're using. This will give you a ratio of dry ingredients to eggs. For example, if your dry ingredients weigh 200 grams and you're using one large egg, which weighs about 50 grams, your ratio is 4:1. So, for every 200 grams of dry ingredients, you need 50 grams of egg. When you double the recipe, you can adjust the amount of eggs accordingly.

It's important to note that the size of the eggs you use will affect the ratio. Large eggs weigh about 50 grams each, while extra-large eggs weigh about 57 grams. So, if you're using extra-large eggs in your original recipe, you'll need to adjust the ratio accordingly when doubling the recipe.

Additionally, if you're only doubling part of the recipe, such as the dry ingredients, you can calculate the amount of eggs needed based on the ratio of dry ingredients to eggs. For example, if your original recipe calls for two cups of flour and one egg, you can calculate the ratio as 2:1. So, for every two cups of flour, you need one egg. If you double the amount of flour to four cups, you would need two eggs to maintain the same ratio.

Keep in mind that these calculations assume that the eggs are being used whole. If your recipe calls for separated eggs, where the yolks and whites are used separately, you'll need to calculate the ratio separately for each. Weigh the yolks and whites separately, then calculate the ratio based on the weight of each to the dry ingredients. This will give you a more accurate idea of how much of each you need when doubling the recipe.

In summary, partial ingredients, especially eggs, can be a tricky part of doubling a recipe. By using ratios and weights, you can calculate the amount of eggs needed for the doubled version. This ensures that your baked goods turn out perfectly, even when adjusting the recipe.

Frequently asked questions