How long can food stay fresh in the fridge?

Factual Questions
1

Hi!

I had just stayed out by myself and began to learn how to cook and all-that, but one thing that is bothering is how long can food stay fresh in a fridge? Food, such as:

  1. Vegetables and fruits?
  2. Fresh meat/fish? And what’s this whole deal about defrosting them, and not freezing them again?
  3. What difference would ziplock bags make?

Thanks in advance!

2

  1. Vegetables and fruits are generally good in the fridge as long as they remain appetizing-looking. If you see mold or other nasty-looking stuff, you wouldn’t want to eat it. There have been isolated cases of things like E. Coli on spinach or watermelon, but this is not due to lack of refigeration.

  2. Most authorities recommend holding fresh raw meat and fish for no longer than 3 days before cooking, although I stretch that out. It helps to keep your fridge at a low temperature setting. It is perfectly safe to thaw food in the *refrigerator * and refreeze. (It might affect the palatability of the food but not the safety.) What is dangerous is thawing at room temperature, which creates a haven for bacteria. Refreezing does not kill bacteria, just slows them down, and any toxins they have left in the food are still there.

  3. Foods generally keep longer if not exposed to air (but there is such a thing as anaerobic bacteria). Zip-Loc bags compared to what? They are OK and they are not 100% airtight, but they’re better than nothing. I have one of those vacuum-seal machines that is very effective.

3
  1. 1 day less than it takes to go bad. There’s always a lot of unknowns including how long it’s been sitting on the shelf before you buy it. Once you start cooking regularly, there’s always inevitably some bit of produce that’s starting to turn. You’ll start to get a feel of how long things last. Generally, the harder the produce, the longer it can survive. You want to store most produce so that it’s moist but not wet. Keep it fairly humid to keep it from drying out but any surface moisture can encourage mold. For some produce like mushrooms that need to breathe, a paper bag is best for this. For other things, a plastic bag stuffed with some damp paper towels works well.
  2. Freezing creates ice-crystals which pierce cell walls and causes juice to leak out and causes a mushy texture. Ideally, you never want to freeze meat but freezing once causes only a minor decline in quality for lots of convenience. Each additional freeze is going to cause more cell damage. You also want to freeze foods as fast as possible to decrease the size of the ice-crystals. Package your meat as thin as possible and wedge it between two previously frozen blocks of food until solid.
  3. Ziplocs help keep odours from intermingling and also form an airtight seal to prevent moisture loss. For whole vegetables, they’re generally unnecessary but they can be good for keeping cut vegetables and fruits.
4

Eggs last virtually forever.

5

If you want to find out how airtight a ziploc bag is, cut an onion in half and seal it up in a ziploc bag. Then smell the bag. You can smell the onion right through the bag (a freezer bag may not be as bad, the plastic is heavier gauge).

I have taken ziploc freezer bags, put food in, and sucked the air out with a straw before sealing, and the next day it had pulled some air back in.

6

The simplest way to keep food longer is to keep the fridge colder. This is what restaruants and food markets do. Fish monger will sell “fresh” fish on ice. Why this doesn’t count as frozen I do not know, but it tells you a lot.

7

IIRC the watermelon turned out to be cross contamination.

8

For the milk I buy, which is nonfat, I find it starts to taste a bit off right when the “best buy” date as arrived. Rather remarkable, that.

9

re: veggies, I was in Whole Foods the other day and they were selling some kind of lump of something green that you can put in the fridge to make your veggies stay fresh longer. It absorbs some kind of gas that the veggies give off.

10

It absorbs etylene that fruit gives off. The ethylene will cause otherthings to ripen faster, thereby making everything go bad faster. It’s kind of the opposite of putting a banana in a paper bag with a tomato effect. As for how well it works, I have no idea.

11

Yeah, what is that with eggs?

When I think about it, it makes a lot of sense. A perfectly contained thing that is impermeable, but on the other hand, why am I always afraid of old eggs? I have never seen a rotten egg in my life. Why have I been trained to think that eggs go bad much quicker than they do?

12

Well, eggs don’t actually last forever. I encountered a rotten egg once. You don’t want to.
Here’s a guide to storage for all sorts of foods
http://www.ag.ndsu.edu/pubs/yf/foods/fn579-1.htm

Most cases of ‘stomach flu’ are actually food poisoning caused by bad food handling and storage practices. Certain foods like raw fish, meat, poultry and eggs, can contain bacteria which will be destroyed by cooking. However if you touch raw poultry and then, say prepare a salad without washing your hands between, you can transfer the bacteria to the salad and make yourself sick. Same goes if you re-use a marinade. Or use the knife you used to cut the raw chicken to cut the chicken when it’s cooked.

People will also leave food out of the fridge way too long once it’s cooked or keep it too long in the fridge after it’s cooked. Put things away as soon as you can after a meal and don’t leave them out on the counter for an hour if it’s going to take that long to cook your meal. No cooked food will last more than a week unless frozen and many things don’t make it that long. Fish has a very short shelf life.
For more info, the FDA has produced a bunch of fact sheets on safety practices.

13

OMG, this is exactly what I need!

Thanks!