You can make candles from any kind of fat--animal fats such as lard or tallow, or vegetable fats like soybean oil. Although wax candles are the norm now, up until the 1500s, candles were made of purified animal fat. Cow, pig and chicken fat were used most often, though coconut oil, olive oil or cocoa butter are all equally effective. If you are using animal fat, it should be free of impurities and solid in colour.
Use scissors to cut a length of cotton yarn approximately 4 inches longer than the height of your jar. Tie one end around a metal washer.
Cut a length of metal wire several inches longer than the width of your jar. Tie the other end of the cotton yarn around the middle of the wire. Drop the washer into the jar, and allow the length of wire to rest horizontally on the mouth of the jar, so that the string, or wick, is in the centre of the jar and goes from the bottom up to the mouth.
Melt the fat in the double boiler until it is liquid. Pour the melted fat into the jar and allow it to cool.
Remove the metal wire from the wick. Cut the wick so it extends about 2 inches over the top of the jar. You can now use your candle.
You do not need to heat oil, it is liquid at room temperature and can be used and burnt as is.
Do not leave a burning candle unattended.