Sourcing and storing avocado Possible Duplicate:
  What can I do to help my avocados ripen?
  How can I choose good avocados at the supermarket?  




I live in the UK and have a difficult time getting hold of good avocados.

They are generally of two types in the shop, hard and tasteless or soft and brown. I sometimes try to buy the hard type, after a while sometimes they are good, sometimes they seem not to ripen and others they are rotten by the time they are soft. 

They are not cheap either getting on for a £1 each. 

I would really like to know:


How to choose good ones from the shop? Are there types which ripen well, does the shape or color help determine what will ripen well.
How to store while at home? I tend to put in the fruit bowl with Bananas should they be warm or cold in the dark or the light.
Are there good stores in the UK for buying them from (possibly too localized|localised?)
I usually buy green, hard avocados to use them in a couple of weeks. When I'm looking for an almost ready avocado for my guacamole at the supermarket, I look for a not-so-hard one and pop off the stem: this is a tip I found over the internet and it really works. Pulp under the stem should be greenish and not brown or dark, otherwise it's probably rotten. You can usually find your ready-to-enjoy avocado with a couple of pop offs.

Take a look to this link for a more in-depth explanation about popping off the stem:
http://www.nwedible.com/2012/05/never-buy-a-rotten-avocado-again.html

Regarding storage, I put them in a bowl on counter top to let them ripe slowly; in a bag with apples or bananas to speed up things. Once ready, I store them in the fridge. Once opened, I put them in Tupperware: they stay perfectly green.

Keep in mind that if you place fruits near apples or bananas, which naturally produce ethylene, your fruit will generally ripen faster.