This interesting topic made me look a bit further on the world wide web. I was told to avoid using salt and alcohol in stuff that was going to be frozen because both agents prevent said stuff from freezing properly. However, that doesn't seem to be the problem anymore when searching for facts on freezing butter. I searched on Dutch and French websites and all I can say is that most resources contradict each others facts.
What I did learn is that;
- butter is affected by air and light; always keep it well packed, also in the fridge or it will go rancid (we knew that, didn't we?)
- when freezing butter, best to cut large pieces in smaller ones and pack each piece tightly
- keep nicely packed said pieces of butter in an airtight plastic container to avoid the butter from picking up other flavors from the freezer
- butter keeps well in the freezer, also salted one. Most websites are contradictory on the period that butter can be kept in the freezer. Salted and unsalted butter have different storage times. A Dutch website that seems to be somewhat scientific says 3 months for salted butter, 6 months for unsalted. Other websites say exactly the opposite and publish very different storage times, up to one year for salted butter...!
- that same Dutch website says to avoid to store salted butter in the freezer since salt speeds up the oxidation process (sounds very right to me)
- All websites from resources in France say that salt in frozen salted butter can seriously alter the taste of butter, kind of makes it much too strong tasting. Not one resource publishes why. Salt does it, of course, and then?
Don't know what exactly "salted butter" means in the US. Over here we have 2 kinds; lightly salted (mi-sel) with a salt content lower than 3% and the common salted butter which has 3% salt or more.
Many websites advise to add your own salt to butter so you can choose which salt to use and to dose your own salt content.
When I come to think of it, 500 grams of butter (1 lb) has a full tbsp. of salt in it (1 tbsp is 15 grams, around 3%). That seems like quite a lot!