Grinding fresh when required

Seeds can best be ground right before usage: ground spices lose their flavour relatively fast. If you want to store powders, put them in an airtight can and preferrably store in the freezer: this way they remain relatively fragrant and fresh, however, grinding 'on the spot' is still recommended.

Heating

Almost all spices are roasted before usage, most in a dry pan, some (e.g. fenugreek) in a bit of oil. Some spices (such as cumin) you can leave until smoke is rising from the pan: this is good, because it removes the more volatile, sharper taste and brings out the more nutty character of the spices. After heating, cool down a bit before grinding.

Different stages

Spices are added in different forms, in different stages of the cooking cycle. Usually some spices are added to the oil or ghee before the onions, this is often called the 'whole masala', whole spices such as bay leaves, cumin, mustard seeds, but also cardamom, cinnamon and cloves, and dry red chili pepper are fried in the oil, until the seeds begin to pop or the smells come free. Then the onions are fried, after a while garlic, ginger, green chilies and such are added (sometimes referred to as the 'green masala'), after that tomatoes (if any) and spice powders (the 'ground masala') and salt. When the tomatoes are soft, curd, vegetables and/or meat is added until done, and the dish is served (sometimes) with some seasoning.

Spice list

A short description of commonly used spices:

• cumin

  long, rice grain-shaped green and brown seeds, used in a huge variaty of dishes (relatively well known in western cooking as well)

• coriander

  round seeds from the coriander plant, of which the leaves are also used a lot; fine, fresh/nutty taste, used as whole or ground masala

• turmeric

  yellow root, mostly sold as fine yellow powder, used very often both for the nice yellow color it gives to the food (colors are very important in the Indian kitchen) and it's not very strong, but still slightly hot taste

  usually added as part of the ground masala

• mustard seeds

  little round black or yellow balls, the black form is mostly used, often added to fish and vegetable dishes with the whole masala

• chili

  in the Indian kitchen usually little green peppers are used to add to the dish at the same time as garlic and ginger, while red pepper (of the same variety, also the small, spicy ones) is added as part of the whole or ground masala

• black pepper

  doesn't need introduction I guess ;) not used a lot, mostly in garam masala and cucumber salads (raitas), can be heated before use but not really necessary

• nutmeg

  nutmeg is a round nut with a very distinctive, strong smell, not used often but some ground masalas (e.g. garam masala) contain it

• mace

  mace is the skin that covers nutmeg on the tree, it has quite a similar taste , albeit somewhat softer

  also mostly used in ground masalas

• cardamom

  cardamom pods are available in green and black varieties the green ones have a fresh, spicy peppermint kind of flavour, while the old have a far thicker, somewhat tobacco-like smell

  used as whole masala in curries and (green) desserts

• fenugreek

  seeds are light brown and irregularly shaped, have a sweet smell, need to be fried in a bit of (usually corn) oil until they are darker brown and start to pop; after frying they taste nutty

  fenugreek is very easy to sprout, yielding tasty alfalfa-like sprouts, the mature leaves are usable as herb or vegetable (like spinach, only with a sweeter taste and stronger smell)

• fennel

  fennel seeds look a lot like cumin, but are greener and smell a bit softer, they are used in chicken and some spice mixes

• onion seeds

  tiny black seeds, look exactly like nigella but have a stronger (not very nice, a bit like old onions) smell, used mostly in batter for frying

• nigella

  also tiny black seeds, less strong and somewhat peppery, not used very often, also mostly in batter for frying

• bay leaves

  laurel leaves (in India they actually use a different variety, Indian bay leaves are not easy to get here though), use as part of the whole masala

• ajwain

  look like small roundish cumin seeds, smell a bit like thyme, used in certain spice mixtures and samosa dough

• asafoetida

  very strong smelling resin-like gum (called 'devil's dung' in several languages), used in very small quantities to give extra flavour to dishes

  usually added with the whole masala, although it's a powder it needs to fry a bit

DISCLAIMER: I am far from a 'guru' in this area, I'm basically just writing down what I think I understand with my very limited background in home cooking... My information may be partially or totally wrong; if it is, please drop me a line...