Cooking with fresh ingredients is best -- of course. But fresh ingredients don't "keep" well.
One of my favorite ingredients is ginger. I purchase it from a local market in Torrance, CA called Randy's Market on Sepulveda Blvd. If you've never been, grab your reusable bags, cash or checkbook, and get there NOW. This place offers the best produce and the best prices: Granny Smith Apples cost me anywhere from $1.49 a lb to $1.99 a lb at the grocery store. At Randy's they cost around $0.59 cents a pound (maybe even less!).
Back to ginger...
Ginger just doesn't keep well. The second you slice into it and get what you need out of it, you may as well toss the rest. However, a Thanksgiving 2008 discovery has allowed me to sustain fresh ginger in my apartment for 2 weeks!
The ginger inside the bag with the air sucked out. Please accept my apologies for the bad photo...
This magical discovery is the Ziploc Freezer Pump and Bag. As someone who covets all modern kitchen technological advances but has no place to store them, you can imagine my excitement when I found this somewhat archaic version of food storage at my Vons. (In case you can't imagine my excitement, picture a blonde jumping up and down on the foil and saran wrap aisle, channeling my inner Monica Gellar as I repeated over and over again "This is the coolest thing ever!")
What it is: a very affordable version of those vacuum seal food storage systems on infomercials.
How much it costs: if I remember correctly, the starter kit, which comes with a pump and 3 bags, clocks in at around $9. (It might be a little more...)
How it works: the special bags have a "hole" in the upper right hand corner that acts as a valve. Once the pump is placed over the hole, pull the pump up and down to suck the air out of the bag.
Down side: if you're sealing something to be left out on the counter, sometimes air will re-enter the bag after a day or so, and you'll have to "re-pump" the air out. This doesn't seem to happen with stuff put in the freezer or refrigerator.
Definitely don't: use with a liquid marinade. The pump will pull the liquid out of the bag and it gets a little messy.
If you're totally over throwing away perfectly good food just because it's not filled with preservatives that keep it fresh, MAKE THE INVESTMENT IN THESE BAGS TODAY. I've used them in various ways: freezing turkey meat, keeping cream cheese and regular cheese fresh and mold-free in the refrigerator, and most recently, keeping my ginger in good standing!
The bags also came in really handy at Thanksgiving when I wanted to save myself some time: I pre-chopped onions and leeks the night before, and the next day when it was time to add those ingredients to my stuffing, they were fresh and ready to go!