From 1906:
When putting up sauces and relishes for winter use, care should be taken that the bottles and jars are perfectly air-tight, and this fact cannot be assured if the corks are simply fitted into the necks and tied down in the usual manner. Corks are more or less porous. The corks should be first dipped into a mixture of one quarter pound of beef suet and one half pound of beeswax, melted down over a slow fire, and be dried at the fire afterwards, this process being repeated several times. Then press the cork into the neck of the bottle and dip the heads and rims into a solution of one-eighth ounce of beeswax melted down with one pound of sealing wax and the same quantity of black resin. When making this mixture, it is well to stir it with a long tallow candle, the wax preventing it from sticking to the bottom of the pan. Sauces, relishes, pickles, liniments, etc., bottled in this way will be in good condition to “keep” indefinitely.