I buy most of my groceries at Costco but, being a family of only 2, sometimes the amounts are simply too much for us to use at once. So I have learned to store most items to avoid spoilage and waste.
I freeze anything I can: sliced bread, tortillas, cheeses (sliced, shredded or whole), butter, raw meats, sauces (pesto, indian cooking sauces, etc), fresh pasta (tortellini, mezzelune, panzerotti, etc), cold cuts and so forth. I also freeze eggs (unshelled, they can be frozen in ice trays, then stored in ziplock bags and used for any cooked applications when thawed). I always thaw in the fridge overnight and consume the items as I would if they were fresh. So far, I have had no problems with this method. Some items like Feta however, need further action to preserve them even longer, once thawed.
Feta cheese can be preserved in 3 different ways: with milk, if you desire to reduce the salt content (just cover the feta with whole milk and store in an air tight container in the fridge), with extra virgin olive oil, if you desire to have a more pungent, strong cheese (just cover the feta with EVOO and store in air tight container in the fridge) or with brine. Brine is the most common commercial storing method, and it is also what I prefer. Brine is easily made, once one figure out the proper ratio between salt and water. The common recipe is: 1 gallon of water to 1 lb of salt, but I found it impractical for household use. I don't need a gallon of brine, so I scale down the recipe for 1 brick of Feta cheese.
Here is what I do:
Mis En Place:
1 Brick of Feta Cheese
1 Air tight container (I opted to save a commercial Feta container --next to the salt, top left--, as it is the perfect size, easily recognizable at a glance in the fridge, but most importantly it is spill-proof!)
1 Cup Water
1 oz Sea Salt
1 Digital Scale
I slice the Feta to fit into the container (the size of this plastic-wrapped-brick is slightly different than what usually comes in this particular container). The cheese needs to be covered by brine to be preserved, so it is important that it lays flat in the container.
I measure one cup of cold water...
...I then zero-out the scale by placing my container on it and pressing the tare button.
Measure one ounce of sea salt
(my scale measures both pounds and ounces, so the display reads 0 lb 1.0 oz)
I combine the salt and water...
...and mix well, until completely dissolved.
At this point I pour the brine over the cheese...
...et voila'. Nothing left to do but store it in the fridge. I find that in brine Feta lasts for months at the time. I have yet to have this cheese go bad or mold. It is such a versatile cheese and can be used in salads, quiches, frittate, and much, much more...