The acorn is the seed of the oak tree (genus Quercus). Although known to have been an important food for native Americans, anyone who has tried to eat one without leaching it will regret the experiment tremendously. It is bitter to the extreme.
Because of the above, I have never gotten too excited about reports you can make wine from acorns. However, a recipe passed on by Dorothy Alatorre has caught my interest. It reportedly makes a full-bodied, Sauterne-type wine with pale golden color. Gather the acorns as they fall--before the squirrels and insects claim them.
Shell and chop the acorn meats in a blender or food chopper. You need one cup of chopped acorn meats, not one cup of acorn meats chopped. You can use some of the water to aid in chopping them if necessary, although newly fallen acorns that are still slightly green are soft enough to chop without the water. Bring a quart of water to boil and add the chopped acorn meats. Adjust heat to a simmer, cover, and cook for 30 minutes. Put half the sugar in the primary and strain the acorn-water onto the sugar. Stir until thoroughly dissolved. Add remaining water to equal one gallon. When cooled to room temperature, add all igredients except yeast. Cover and set aside 12 hours. Add activated yeast, recover and ferment 5-7 days. Stir in remainder of the sugar until disolved and transfer to secondary. Fit airlock and ferment 30 days. Rack, top up and refit airlock every 60 days for 6 months. Stabilize, sweeten to taste, wait 10 days for dead yeast to fall out, and rack into bottles. May taste after 6 months. [Adapted from recipe by Nancy McCoy, as reported in Dorothy Alatorre's Home Wines of North America]