What is the best way to store dark chocolate to preserve chocolate and flavour?
Chocolate should be stored in a cool, dry area whenever possible. A cold basement or wine cellar is perfect.
Moist environments, including the refrigerator, can cause the chocolate to bloom. This is when the cocoa butter separates and you start to see a white film at the top. It's actually still safe to eat this way and won't even affect the flavour much, it just looks a little odd.
That said, even tempered chocolate (i.e. baking chocolate squares) will melt at hotter room temperatures, so if the air is humid or you're in a hot climate, you'll typically want to refrigerate. Also, if you've just melted the chocolate to make a coating and haven't tempered it, then you must refrigerate it as it will melt even at colder room temperatures.
Otherwise, it's best not to refrigerate. It will generally keep for a year or more at 55-60° F (about 13-15° C).
Thanks for the idea of using a wine cellar for keeping chocolate cool. I live on the Big Island of Hawaii. I keep lots of cooking items in the fridge because the pantry is too warm for long term storage. And I have a big wine cooler that runs at 64 F. The fridge is at 33 F. Perfect!! Mahalo! And Aloha! Jul 20, 2017 at 0:29
Why did you say that it looks odd? Atleast for some chocolates like "dairy milk" it tastes better. Also, sometimes keeping in refrigerator some chocolates break into powder. That has its own advantages and disadvantages. The advantage is that since the surface area is increased,more amount of chocolate falls on taste buds creating more sensation– RitilAug 4, 2022 at 18:01