Causes of Spoilage
As already mentioned, honey contains bacteria and yeasts. These, like the yeasts and bacteria on the skins of fruit, are the main causes of spoilage. The method we shall use, ensures that they are destroyed; I mention them because too many people are still trying to make mead without sterilizing the honey-water mixture before they begin. If not sterilized, these yeasts and bacteria will almost certainly start spoiling ferments to produce souring, bitterness or vinegar flavours. In its undiluted state, the concentration of sugar prevents their action, but as soon as this is reduced by diluting with water, they are ready to spring into action and spoil the mead. Where small amounts of mead are being made - say one or two gallons at a time - boiling the mixture is the easiest means of sterilizing. But where larger amounts are being made, a large enough vessel for boiling might be hard to come by; in this case, the mixture may be sterilized by adding two Campden tablets per gallon. These are crushed and dissolved in a little warm water and stirred into the mixture. This is left for a few hours and then given a brisk stirring before the yeast is added. But as most beginners will be making one or two gallon lots to start with they will do the heat sterilization method as given in the recipes.