Yes. Butter can be kept at room temperature (below 80F) up to a month, if it is protected from air. The most popular way to do this is with a "French butter keeper", a cup that is inverted into water. That particular design was invented a little over 100 years ago, but methods for keeping butter fresh without refrigeration have been around for centuries.
Yes, not all butter is salted. If you leave any butter out for several days at room temperature it will become rancid, the same as any other fat-containing food. You will know when it is unfit to eat because of unpleasant changes in the texture, color and smell. Butyric acid is one pungent component of the decomposition of butter and it is also found in vomit (see link).ANS2:No - Salt is a preservative.
Butter will be OK for at least a couple days after the power goes off. The concern is more about quality and rancidity, not food pathogens.
Not really if you are not on a salt restricted diet: the amount of salt in butter isn't too high unless you are eating a lot of it. The reason for unsalted butter is that some recipes that use a lot of butter might taste a little too salty if you use the salted kind (shortbread, for example). Also, if the butter is not salted you can better control how much salt goes in the final recipe. HOwever, unsalted butter does not last nearly as long because salt is a preservative, so you should use it quickly and freeze it if you are keeping it more than a few days.
According to Butterball's website, an unopened turkey can be kept in the freezer for up to 2 years. Use a deep freeze freezer that is not frost-free. Frost-free freezers go through defrost cycles which have temperature fluctuations that could cause freezer burn.
nine dollars a kilo in the old days
You don't.
One to two days in the refrigerator.
An uncooked turkey should be good 1 - 2 days stored in the refrigerator.
Spareribs should be safe for 3 - 5 days if stored in the refrigerator.
Most foods should be safe for 3 - 5 days if stored in the refrigerator.
It depends on how cold your refrigerator is and how fresh it was when you put it in.
That depends on a lot of factors prime is probably if it is salted or not (and if so how salt) and how fresh it is as well as how sour the cream was when the butter was made. a few days is no problem, weeks is less probable, more than a month is very unlikely.