Start with several pounds of very lean beef roast. You should choose a roast with visible grain, if possible, and little or no fat. It needn't be very high quality, and in fact, tougher cuts seem to actually work better.
Mix a marinade with some or all of the following:
Mixing the sauce is largely a matter of taste. The result should be close to 3 parts soy sauce, 1 part Worcestershire, 1 part brown sugar and the rest as desired. It should be a very strong salty, spicy and slightly sweet solution. The rest of the ingredients depend on your taste, and the list is by no means exhaustive.
Adding red wine will decrease the saltiness and/or dilute it if you get it too spicy without affecting the flavor greatly. You should not use more than about 30 to 40% red wine, however, since the saltiness is necessary to preserve the meat. Don't get too hung up on the recipe, it is good just about any way you fix it.
With a very sharp knife, slice the uncooked roast with the grain (usually lengthwise down the roast) into strips about 1/8 inch thick. Thinner will make the jerky spicier and crisper, thicker, up to about 1/4 inch will make it easier to slice, but increases drying time.
Trim fat once again, and put the slices in a large Ziploc bag with the marinade. Squeeze to remove as much air as possible, and have a helper seal the bag. Let soak at room temperature for at least an hour.
Remove the strips and place in a dehydrator. Spread them in a single layer on each rack, and sprinkle with great quantities of black pepper on one side. Dry on high (145 degrees) in the dehydrator, or turn your oven temperature selector until the light just comes on (the lowest setting possible) and dry on a rack in the oven.
In the oven, prop the door open about 3 inches at the top. Drying time is about 8 to 10 hours, but can take twice that long for thicker pieces. Bending should splinter some of the outside fibers when done.
It should keep at room temperature for a couple of weeks, and will actually get better in a day or two as the moisture content becomes more uniform throughout.
