Making a Curry Paste from Scratch (3)
by Kasma Loha-unchit
Tips on Prepping Herbs and Spices
See Kasma's blog entry on the Mortar & Pestle.
Herbs reduce easier in the mortar when they are cut into small pieces or chopped ahead of time. This is especially true with lemon grass, which has tough fibers running the length of the stalk. Slice it into thin rounds before pounding, or your paste may end up with a stringy texture. Reconstituted dried ingredients, such as kaffir lime peel, also benefit from cutting with a sharp knife beforehand. Although softened by soaking, the once-dried zest can still be tough and sometimes pounds to a flat piece without breaking down. If you can, avoid pounding dry spices with fibrous herbs because they frequently cushion one another and end up taking longer to reduce. For those who seek short-cuts, the wetter herbs like garlic and shallots chop easily with the aid of a chopper or mini-processor, and the dry spices pulverize quickly in a coffee grinder designated specifically for grinding spices – but always pound them afterward to release their flavors fully.
For curries with roasted fragrances, such as massaman and panaeng curries, roast the dry spices in a dry pan over a medium flame and cool before pulverizing. I usually roast the different seeds separately, as the smaller ones like cumin take less time than the larger ones, like coriander seeds. While roasting, seeds release their perfume into the air before they brown, so let them go a while longer after you begin to smell their roasted aromas, or until they are uniformly dark, but not burned. This way the seeds are roasted through to the core and not just toasted on the surface. Stir or shake the pan frequently for even browning. Darkly roasted seeds will permeate a curry with stronger roasted flavors than lightly toasted seeds; burned seeds will make the curry bitter.
Dried red chillies are dry-roasted the same way as seeds, by placing them on a dry pan over the stove, but be careful to watch them closely. They may do nothing the first minute, then all of a sudden burn quickly. Turn often so they darken evenly. You do not want to burn chillies as they release fumes into the air that irritate the mucous linings of the throat all the way down to the lungs. Make sure you have good ventilation. Burning fumes are less likely if the chillies are roasted before de-seeding, as chilli dust from the inside membranes of punctured chillies burns easily on the hot pan. If there are several ingredients that require roasting, I always save the chillies for last, to avoid the possibility of burning traces of them on the pan while I roast the seeds.
For recipes that call for dried chillies, I usually remove and discard the seeds. The flavor of most dried chillies lies mainly in the red skin and dried pods; the seeds are hot but hold less flavor. De-seeding allows you to use more pods for added flavor (as well as for a redder color) without the paste becoming too hot. There are two ways to prepare dried chillies for paste making. They can be ground dried to a fine powder, then pounded with other wet ingredients to form a paste; or they can be soaked first to soften, then chopped and pounded into paste. The latter method seems to produce a curry paste with a fresher-tasting chilli flavor. I usually use the soaking method for pastes using chillies that are not roasted, and the dried-ground method when roasted chillies are called for, to preserve the roasted flavor. To soak, cut off the tip, turn the chilli head down and squeeze out the seeds before putting the chilli in a bowl of water. This allows the water to penetrate to the inside, thereby softening the chillies faster. Avoid using hot water for soaking as it leaches out the more delicate flavors in the chilli pods.
For recipes that call for roasted garlic and shallots, the roasting can be easily accomplished in a toaster oven rather than over the less convenient, traditional charcoal pit. Cut the root ends of the garlic cloves and shallots, leaving the skins on (this prevents them from bursting and creating a sticky mess in your oven). Place them on a tray in a hot oven (450 degrees). Check after five to ten minutes and remove the garlic cloves once they have softened and started to ooze out. Shallots usually take longer, depending on their size. Roasted garlic and shallots pop out of their skins when squeezed with the fingers; they mash up easily in the mortar.
Almost all Thai curry pastes are flavored with gkapi shrimp paste. For recipes that call for roasting gkapi, wrap the amount needed in a small section of banana leaf, hold the packet with tongs and stick it directly into the gas flame of a burner. Turn frequently until the leaf is well charred and the odor of gkapi begins to escape. Remove from the wrapping and pound into the curry paste. In Thailand, gkapi is roasted in charcoal embers; this is easy to do in kitchens equipped with charcoal stoves. If you do not have a banana leaf, substitute with aluminum foil, though this will dry the paste out considerably.