If you homebrew, you may be quite happy brewing normal beer with extracts. At some point, you may want to break away from normal, and dabble in the experimental. In their book, Brewing Classic Styles: 80 Winning Recipes Anyone Can Brew, Jamil Zainasheff and John J. Palmer present a boatload of recipes based on the use of extracts, modified with a few adjustments: a grain bag for steeping, unusual ingredients, or a partial mash, for example.

Sam Calagione of Dogfish Head Craft Brewery throws out some brewing mods in his book, Extreme Brewing: An Enthusiast’s Guide to Brewing Craft Beer at Home. Both books encourage an artisan’s hand in stepping outside the box, into the world of the extreme.

Some ingredients, although unusual, are more commonly used with success. You will see these over and over in homebrew forums and books on extreme brewing. I have compiled a short-list of a dozen of these little beauties. Use them freely during the times you feel the urge to experiment, and keep a record of what you did so you can repeat it if you should find that it titillates your taste-buds.

A Dozen Special Ingredients for Brewing in the Extreme:

Licorice Root contains a natural acid called glycyrrhizin, a sweet tasting compound that has 30-50 times the sweetness of sucrose, but it reacts in the mouth differently. The taste buds do not detect the sweetness as rapidly; the sweetness, once activated, lingers longer.

Crystallized ginger can be made at home by slowly cooking ginger in sugar water, then rolling it in sugar to preserve it. It has a sweet and spicy taste that adds zing to recipes.

Wormwood has a long history in brewing, dating back to Norway. It adds long bitterness and was used as a substitute for hops.

Spruce was used in beer and is a key ingredient in brewing Sahti. It was a key ingredient for the American colonists, particularly because it helped to ward off scurvy.

Chinese Rock Sugar comes from sugar cane juice that is cooked until it begins to color. A string is put in the raw sugar cane juice and it crystallizes around the string.

Kiwi Fruit can be briefly soaked in hot water to make it easy to peel. Cut into cubes and use in place of orange peel in Witbier.

Rye can add spiciness, along with mild tones of woodsy character.

Dandedlion flowers are used to make wine in many rural parts of America, but young dandelion plants, which sprout in early spring, can be used as an ingredient in beer. Using the leaves and thick tap roots, it can be boiled with lemon and ginger before adding to Demerara sugar. It is also mixed with nettles for another version of extreme beer.

Peppercorns add heat and spice:

• Pink peppercorns are not true peppercorns, because they are actually ripened berries of the Baies Rose Plant. They are spicy and sweet.
• Another type of “Pink Peppercorns” come from the Brazilian Pepper Plant and has a sweet menthol and resinous profile. They can be poisonous in high quantities and are best avoided.
• Green Peppercorns are undried black peppercorns. If they are not preserved in vinegar, they must be used quickly, because they do not last.
• Black Peppercorns are green peppercorns that have been dried in the sun.
• White Peppercorns are matured berries that have fully ripened to red; then are soaked and rubbed to remove the skin. They are not as spicy as the Black version.

Molasses can be made from sugar cane or sugar beets and is a thick viscous liquid that looks like dark, melted glass. First molasses has the highest sugar content; second molasses is produced in a second boiling and takes on a hint of bitterness; blackstrap molasses comes from a third boiling and is pungent, robust, and contains trace amounts of vitamins and minerals.

Cherries, including the pits will add a full-fruit sweet-tartness, while the pits will contribute a woodlike flavor.

Gesho Tree Root is African in origin and is used for bittering. It may be ground or shredded before using in your recipe.

These should keep you going for awhile. Enjoy your brew days, and add your thoughts to the forum. I’d love to know whether you are succeeding, and what ingredients you find pleasure in using.

Cheers!

Take a look at Jamil and John's book on brewing with extracts:
Brewing Classic Styles: 80 Winning Recipes Anyone Can Brew

While you're at it, maybe a good basic book will help:
How to Brew: Everything You Need To Know To Brew Beer Right The First Time