Angostura® bitters
Angostura Bitters is made from a blend of rare tropical herbs and spices. Although the single ingredient named on the label is gentian, The exact formula is a closely guarded secret.

It is said to contain over forty ingredients, and was developed in 1824 by Venezuela Surgeon General Dr. J. Siegert who spent 4 years devising the recipe that would improve the appetites and well-being of his troops.>
Used in Manhattan cocktails.
45% alcohol

bitters
Bitters are highly concentrated flavoring agents made from roots, barks, herbs, and/or berries, dissolved in alcohol or glycerine and having a bitter or bittersweet flavor.
Commonly have an alcoholic strength of up to 45%
See: DrinksMixer.com
Peychaud bitters
A gentian-based (flowering plant) bitters, comparable to but with a lighter body, sweeter taste and more floral aroma than Angostura brand bitters.
35% alcohol.
I went 4 liquor stores and none had Peychaud's,
Search at www.wine-searcher.com
Vermouth
Blend of white wines fortified with additional alcohol and flavored with aromatic herbs, spices, and roots. It contains up to 19% alcohol. The sweeter, darker type of vermouth (15% alcohol) is sometimes called Italian vermouth (e.g. Cinzano ) , and the lighter, drier type, French vermouth (18% alcohol). Used in Manhattan and Martini cocktails.
Links:
Liqueurs
Bitters

last updated 25 Jan 2009