I get this question often. The best thing to do is to buy your spices in bulk with a spice purveyor. Spices go bad much easier than you would think. The average shelf life of ground spices is roughly 3 years, in the case of whole spices, 4 years. The problem comes into play when you buy a prepackaged spice. You don’t know how long that was sitting on the shelf at your grocer, or at the warehouse, or at the bottling facility. A spice purveyor will provide spices to you fresher than they are before they make it to a bottling facility. You can usually find good deals at “international markets,” or with an online spice purveyor that sells them by the ounce. Once you receive them, put what you will use in an airtight container and store them in a cool dark place. Keep the bulk product in a cool dark place also.
If buying spices in bulk is not an option, still store your spices in a cool dark place. Heat, light and air, will minimize the effectiveness of your spices; and, in some cases they can spoil.
Another thing that many people don’t do is cook their spices. Many people spice at the end of the cooking process. In that situation your spices are raw. Spices are like your other ingredients and need to cook. You want to cook with a solid foundation or base to the meal you are cooking. A major part of that is starting with your spices in the mix. You also want as much surface area of your spices exposed to the heat while cooking. This is where a coffee grinder or mortar and pestle comes in handy. Add in all the spices you are using and grind them. This will allow them to release their oils and flavors more readily. It’s an extra step, but it takes all of 2 minutes and pays off in dividends of added flavor. In the case of most Cajun and Latin cuisines toasting those spices in a dry pan is another trick that can really kick that flavor up a notch. Warm up your pan, add in your spices and keep them rolling in the pan until you smell them becoming fragrant. Remove them and then start cooking your meal. Add them back in when appropriate. In most instances that is when add your garlic to the trinity or mirepoix.
In the case of herbs, fresh is always the best way to go. Dry herbs work in some cases, but fresh herbs work in all cases. There is a flavor you get from fresh herbs that no amount of dry herb can replace. Similarly to spices, you want to maximize the surface area of the herb that is exposed to the heat, to ensure the oils are released into the dish. If you have no choice but to use dry herbs, use your grinder or mortar and pestle to help them get an added fresh surface area. If you have neither of those things grind them between your fingers. Dry herbs are so dry that when added to the dish, they almost disappear and will not have much flavor. The oil has mostly been removed in the drying process. You have to really break them down to get them to release flavor.
Personally, I shy away from a lot of the premixed seasonings in favor of putting together my own blends. I do keep a jar of slap ya momma on hand; however. I also make a mix of 1 part salt to 4 parts black pepper and 1 part garlic powder. I call it SPG, and I use it as a base for seasonings on most proteins and vegetables. I try to make sure that the same flavor profile works through all of the elements on my plate. If I’m roasting chicken, I use the spg as a base layer of seasoning and then add some to the vegetable side. The familiar flavor from one part of the meal to the other adds an element to the overall meal. Other blends I will make are dependent on whatever meal I am preparing. I’ll make my spice blend for the meal as part of my prep process or I’ll throw it together the night before. In the case of Cajun food, I’ll blend together red pepper, black pepper, paprika, cayenne, thyme, garlic, and salt. For Mexican I’ll put together some lime zest, salt, black pepper, red pepper, cumin, garlic, chili powder.
Seasoning is a chance to really differentiate your dish, so take advantage of the opportunity to play around and find something you like.
I hope this was informative and helpful, next time you’re cooking try making your own blend from what you already have, toast them up and then start cooking as you normally would; but, use your toasted spices and see if you notice the difference.