If a candle shows bloom that's actually a good thing. Over time candles that are pure, made of 100% beeswax, will develop a soft whitish film called "bloom" on their surface. It's actually an indication of the candle's purity and does not mean the candle has gone bad.
There's no need to wipe off the bloom but if you prefer it gone you can rub the candle with a soft cloth or polish with a pair of nylons. Or warm the outside with a blow dryer.
This is one of the first candles made by Barb over six years ago and is showing the whitish bloom.
Any candles that aren't made with 100% beeswax will not show bloom so in fact a pure candle should bloom if it has aged.