To brew hard apple cider, start with fresh preservative-free apple cider. Add brewing yeast, then let it ferment for approximately three weeks. After it ferments, bottle it, and drink it as desired.
You can make the non-alcoholic cider yourself if you have a press, or you can buy commercially produced cider. If you buy commercial cider, make sure that there are no preservatives, as these tend to kill the brewer's yeast and prevent fermentation. It is best if it is cold-pasteurized, which does not affect the taste as much as heat pasteurization does.
Before you add the yeast, simmer the sweet cider over medium heat for about 45 minutes in order to kill the naturally occurring yeasts and bacteria. You can also add brown sugar or honey to help the fermentation process, but this is optional. Have a sanitized fermentation bucket ready and when the cider is done simmering, let it cool and then add your yeast. The mixture needs to be stirred for a couple of minutes to thoroughly mix and aerate it. Afterwards, seal it, and place it in an out-of-the-way location like a closet or corner. This location should be out of direct sunlight and kept at a temperature between 60 and 75 degrees Fahrenheit. Keep an eye on it. It should bubble for about two weeks, and when it is done bubbling, let it sit for another week or so before bottling or drinking.