Convert seed based measurements to pre-ground?

Question

I want to use a recipe that gives ingredient measurements based on the spice seeds. My local grocery store does not have at least half of the ingredients in seed form. But the store does have them pre-ground. How can I translate this recipe's measurements into something I can actually buy?

Ingredients:

• 1 1/2 dried chipotle chiles, stemmed, seeded, chopped
• 2 tablespoons pink peppercorns
• 2 tablespoons coriander seeds
• 1 teaspoon fennel seeds
• 1/4 teaspoon cumin seeds
• 2 teaspoons dark brown sugar
• 2 teaspoons kosher salt
• 1 teaspoon mustard powder

Read More http://www.bonappetit.com/recipes/2011/07/chipotle-rub#ixzz1Qo0PBoPp

Answer

Converting whole spices to ground spices is not as simple as matching up the weights. Ground spices have a distinctly different flavour from the whole. The freshness of the grind will also affect the taste quite considerably as well as how carefully they have been stored. When the spice is freshly ground it will have a very strong intense flavour, so you would reduce the amount you use slightly. However, ground spices rapidly loose parts of their flavour. The taste changes and you may find you will end up using more than the recipe states in order to get a similar taste. However, you'll never get exactly the same taste, grinding changes the spice.

The best solution is to try to get an supply of the whole spice from an online store. You can then use them whole or grind them yourself, fresh, as the need arises.

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