1. Changing the Yield of a Recipe
Halving and Doubling

2. Why chanGe the yield of a recipe?
Because you need less of a recipe.
Because you need more of a recipe.
Because you have a limited amount of ingredients.

3. How to Double a Recipe
Write each of the ingredients on a piece of paper. 
Chefs don’t recommend scaling a recipe in your head. You should write out the amounts you need ahead of time.

4. How to Double a Recipe
Separate your ingredients into four columns (or as many as necessary).
Write down all of the vegetables, flour, and meat products in one column. 
Write down the seasonings in a second column.
Write down the liquid ingredients in a third column.
Write down rising agents and alcohol in the last column.

5. How to Double a Recipe
Above each column, write the number by which you will times (x) the ingredients.
Write “x 2” above the main ingredients column and above the liquids column.
If your recipe requires the use of alcohol, use 1.5 x the amount listed.  Avoid "eyeing it", or pouring it based on instinct - alcohol has a strong flavour and will become too concentrated if doubled. 
Write “x 1.5” above the seasonings column.
Consider ingredients like soy sauce, Worcestershire sauce, and other concentrated sauces to be seasonings.
Increase chili peppers and other hot spices by 1.25 x the original recipe. This includes curry powders, garlic powders, and fresh hot peppers.

6. How to Double a Recipe Recalculate your baking soda quantity.
To rise properly, you need 1/4 tsp. (1.15 g) of baking soda per cup (125 g) of all-purpose flour. For example, if you now need 4 cups (500 g) of all- purpose flour, your baking soda measurement should be 1 tsp. (4.6 g).
Include extra baking soda – approximately 1/4 tsp. to 1/2 tsp. – per cup of acidic ingredient. If your recipe calls for yogurt, buttermilk, vinegar, or lemon juice, you will need slightly more baking soda to neutralize the acidity.
If both baking powder and baking soda are in the recipe, it usually means there is an acidic ingredient that needs to be neutralized.

7. How to Double a Recipe Recalculate your baking powder quantity.
To rise, you need 1.25 tsp. (4.44 g) of baking powder per cup (125 g) of all-purpose flour. If you have 4 cups of flour (500 g), you need 5 tsp. (17.77 g) of baking powder.

8. How to Double a Recipe Complete your calculations.
If you have time, rewrite the entire recipe. This will ensure that you follow the recipe exactly with all of the right proportions.
Note: DO NOT double the cooking/baking time, as there is a chance your recipe will burn. A suggestion is to cook for the time the recipe suggests, then check it.  If it doesn't look done, cook it for another 5 minutes or so until fully cooked.

9. How to halve a Recipe
Halving a recipe follows the same basic principles as doubling a recipe.
Instead of multiplying your ingredients by 2, you divide your ingredients by 2.
Note that when you’re halving a recipe, you generally need to change the size of your cook or bakeware to avoid burning.
This applies to your cooking or baking time, as well – assume that preparing something that has been halved requires less time.