To scale the recipe up from 10 servings to 40 servings, you need to adjust the amount of dried rosemary you use based on the ratio of fresh rosemary required.
1. Calculate the ratio of fresh rosemary per serving:
Fresh rosemary for 10 servings = 3 tablespoons
Fresh rosemary per serving = 3 tablespoons / 10 servings = 0.3 tablespoons per serving
2. Now, calculate the total fresh rosemary required for 40 servings:
Fresh rosemary for 40 servings = 0.3 tablespoons per serving * 40 servings = 12 tablespoons
3. Since you don't have fresh rosemary, you'll need to use dried rosemary as a substitute. The general rule of thumb for converting fresh herbs to dried herbs is to use 1/3 of the amount. So for every 1 tablespoon of fresh rosemary, you can use 1/3 tablespoon of dried rosemary.
4. Calculate the amount of dried rosemary needed:
Dried rosemary for 12 tablespoons of fresh rosemary = 12 tablespoons * (1/3) = 4 tablespoons
So, to scale the recipe up to serve 40 people, you should use 4 tablespoons of dried rosemary as a substitute for the 3 tablespoons of fresh rosemary required for the original 10-serving recipe.