I am getting mold on the butter.
While I do not own one of these butter bells, I understand that one must be fastidious and careful not to let any bread crumbs stay in the butter. I've seen discussions where some recommend salting the water to inhibit mold growth.
You say you change the water "frequently" without giving any precise detail. I suggest change more frequently relative to what you are currently doing, perhaps every other day.
Also, you should review your methodology in how you pack the butter into the bell. You should be sanitizing your utensils (spoon, knife, whatever) as well as the butter bell itself shortly before filling.
Can't give much help. I also bought the ceramic butter keeper and have found it impractical to use, even though it does look pretty.
I own the butter keeper. I change the water every day because it is just too warm in my Texas kitchen. I use very cold water. So far, I've encountered no problems
I have had a butter bell for some time. Never had a problem with it until I switched my brand of butter. I usually buy Land O Lakes, but decided to do store brand as it was cheaper. The store brand butter got moldy very quickly (within a few days)! I would change the water often and I still would get mold on the butter. Went back to Land O Lakes and I don't have that issue (unless my butter sits there for a long time). Lastly, I've gone from putting a whole stick in it to just putting half a stick. That way I finish it quicker and can clean it out more often.
Hi there Milford! Hmm, I'm not too certain I know the answer behind why the brand of butter would change how quickly your butter is molding (perhaps it's as simple as how fresh the milk/butter is or the fat content?) however, one of my more science-inclined colleagues might want to take a stab.
I can say that, dependent on where you're located and the temperatures of your kitchen--mold will produce quicker in your keeper if water isn't changed frequently (frequently being more than 2-3x a week). That's the only factor I've noticed having a huge impact when it comes to mold growth.
The amount of butter your using will also prohibit mold from showing. The bell is intended to be kept fairly full so as to create that airtight seal stopping any chances for bacteria to grow. With "frequent" changes of water (I change mine about every 3 days, and thats in my 4th floor *humid* NJ apartment kitchen) you should be on a fairly mold-free schedule!!
To CV's point: I have heard the use of salt in the butter keeper's water to be particularly helpful too! Just be sure you're using unsalted butter in those cases (I've made that rather unpleasant mistake).