The TTB (Transfer and Tax Bureau) is the regulator of all beverage spirits sold in the US. Here are their technical definitions of various whiskies:
BOURBON WHISKEY Whiskey produced in the U.S. at not exceeding 80% alcohol by volume (160 proof) from a fermented mash of not less than 51 percent corn and stored at not more than 62.5% alcohol by volume (125 proof) in charred new oak containers
RYE WHISKEY Whiskey produced at not exceeding 80% alcohol by volume (160 proof) from a fermented mash of not less than 51 percent rye and stored at not more than 62.5% alcohol by volume (125 proof) in charred new oak containers
WHEAT WHISKEY Whiskey produced at not exceeding 80% alcohol by volume (160 proof) from a fermented mash of not less than 51 percent wheat and stored at not more than 62.5% alcohol by volume (125 proof) in charred new oak containers
MALT WHISKEY Whiskey produced at not exceeding 80% alcohol by volume (160 proof) from a fermented mash of not less than 51 percent malted barley and stored at not more than 62.5% alcohol by volume (125 proof) in charred new oak containers
RYE MALT WHISKEY Whiskey produced at not exceeding 80% alcohol by volume (160 proof) from a fermented mash of not less than 51 percent
malted rye and stored at not more than 62.5% alcohol by volume (125 proof) in charred new oak containers
CORN WHISKEY Whiskey produced at not exceeding 80% alcohol by volume (160 proof) from a fermented mash of not less than 80 percent
corn and if stored in oak containers stored at not more than 62.5% alcohol by volume (125 proof) in used or uncharred new oak containers and not
subjected in any manner to treatment with charred wood
STRAIGHT BOURBON WHISKEY· Bourbon whiskey stored incharred new oak containers for 2 years or more · “Straight Bourbon Whiskey” may include mixtures of two or more straight bourbon whiskies provided all of the whiskies are produced in the same state
STRAIGHT RYE WHISKEY· Rye whiskey stored in charred new oak containers for 2 years or more · “Straight Rye Whiskey” may include mixtures of two or more straight rye whiskies provided all of the whiskies
are produced in the same state
STRAIGHT WHEAT WHISKEY· Wheat whiskey stored in charred new oak containers for 2 years or more · “Straight Wheat Whiskey” may include mixtures of two or more straight wheat whiskies provided all of the whiskies
are produced in the same state
STRAIGHT MALT WHISKEY· Malt whiskey stored in charred new oak containers for 2 years or more · “Straight Malt Whiskey” may include mixtures of two or more straight malt whiskies provided all of the whiskies
are produced in the same state
STRAIGHT RYE MALT WHISKEY· Rye malt whiskey stored in charred new oak containers for 2 years or more · “Straight Rye Malt Whiskey” may include mixtures of two or more straight rye malt whiskies provided all of the whiskies are produced in the same state
STRAIGHT CORN WHISKEY· Corn whiskey stored in used or uncharred new oak containers for 2 years or more · “Straight Corn Whiskey” may
include mixtures of two or more straight corn whiskies provided all of the whiskies are produced in the same state
STRAIGHT WHISKEY· Whiskey produced from a fermented mash of less than 51 percent of any one type of grain and stored in charred new oak containers for 2 years or more · “Straight Whiskey” may include mixtures of two or more straight whiskies provided all of the whiskies are produced
in the same state \
WHISKEY DISTILLED FROM BOURBON MASH Whiskey produced in the U.S. at not exceeding 80% alcohol by volume (160 proof) from a fermented mash of not less than 51 percent corn and stored in used oak containers
WHISKEY DISTILLED FROM RYEMASH Whiskey produced in the U.S. at not exceeding 80% alcohol by volume (160 proof) from a fermented mash of not less than51 percent rye and stored in used oak containers
WHISKEY DISTILLED FROMWHEAT MASH
Whiskey produced in the U.S. at not exceeding 80% alcohol by volume (160 proof) from a fermented mash of not less than51 percent wheat and stored in used oak containers
WHISKEY DISTILLED FROMMALT MASH Whiskey produced in the U.S. at not exceeding 80% alcohol by volume (160 proof) from a fermented mash of not less than51 percent malted barley andstored in used oak containers
WHISKEY DISTILLED FROM RYEMALT MASH Whiskey produced in the U.S. at not exceeding 80% alcohol by volume (160 proof) from a fermented mash of not less than51 percent malted rye and stored in used oak containers
LIGHT WHISKEY Whiskey produced in the U.S. at more than 80% alcohol by volume(160 proof) [but less than 95%alcohol by volume (190 proof)]and stored in used or uncharred new oak containers
BLENDED LIGHT WHISKEY ORLIGHT WHISKEY – A BLEND¹Light whiskey blended with less than 20% straight whiskey on a proof gallon basis
BLENDED WHISKEY OR WHISKEY– A BLEND³Whiskey produced by blending not less than 20% on a proof gallon basis (excluding alcohol derived from added harmless coloring, flavoring or blending materials*)straight whiskey or a blend of straight whiskies and, separately or in combination, whiskey of any type or neutral spirits
BLENDED BOURBON WHISKEYOR BOURBON WHISKEY – ABLEND¹Blended whiskey produced in the U.S. containing not less than 51%on a proof gallon basis (excluding alcohol derived from added harmless coloring, flavoring or blending materials*) straight bourbon whiskey
BLENDED RYE WHISKEY ORRYE WHISKEY – A BLEND³Blended whiskey containing not less than 51% on a proof gallon basis (excluding alcohol derived from added harmless coloring, flavoring or blending materials*)straight rye whiskey
BLENDED WHEAT WHISKEY ORWHEAT WHISKEY – A BLEND³Blended whiskey containing not less than 51% on a proof gallon basis (excluding alcohol derived from added harmless coloring, flavoring or blending materials*)straight wheat whiskey
BLENDED MALT WHISKEY ORMALT WHISKEY – A BLEND Blended whiskey containing not less than 51% on a proof gallon basis (excluding alcohol derived from added harmless coloring, flavoring or blending materials*)straight malt whiskey
BLENDED RYE MALT WHISKEYOR RYE MALT WHISKEY – ABLEND³Blended whiskey containing not less than 51% on a proof gallon basis (excluding alcohol derived from added harmless coloring, flavoring or blending materials*)straight rye malt whiskey
BLENDED CORN WHISKEY ORCORN WHISKEY – A BLEND³Blended whiskey containing not less than 51% on a proof gallon basis (excluding alcohol derived from added harmless coloring, flavoring or blending materials*)straight corn whiskey
A BLEND OF STRAIGHT WHISKIES OR BLENDED STRAIGHT WHISKIES· Mixture of straight whiskies produced in different states · Mixture of straight whiskies produced in the same state to which harmless coloring, flavoring or blending materials* have been added
A BLEND OF STRAIGHT BOURBON WHISKIES OR BLENDED STRAIGHT BOURBON WHISKIES¹ A blend of straight whiskies produced in the U.S. consisting entirely of straight bourbon whiskies
A BLEND OF STRAIGHT RYE WHISKIES OR BLENDED STRAIGHT RYE WHISKIESA blend of straight whiskies consisting entirely of straight rye whiskies
A BLEND OF STRAIGHT WHEAT WHISKIES OR BLENDED STRAIGHT WHEAT A blend of straight whiskies consisting entirely of straight wheat whiskies
A BLEND OF STRAIGHT MALT WHISKIES OR BLENDED STRAIGHT MALT WHISKIESA blend of straight whiskies consisting entirely of straight malt whiskies
A BLEND OF STRAIGHT RYE MALT WHISKIES OR BLENDED STRAIGHT RYE MALT WHISKIESA blend of straight whiskies consisting entirely of straight rye malt whiskies
A BLEND OF STRAIGHT CORN WHISKIES OR BLENDED STRAIGHT CORN WHISKIESA blend of straight whiskies consisting entirely of straight corn whiskies
SPIRIT WHISKEY Whiskey produced by blending neutral spirits and not less than 5% on a proof gallon basis whiskey, straight whiskey or combination of whiskey and straight whiskey provided the straight whiskey is used at less than 20% on a proof gallon basis
SCOTCH WHISKEY Unblended whiskey manufactured in Scotland in compliance with the laws of the United Kingdom
BLENDED SCOTCH WHISKEY OR SCOTCH WHISKEY – A BLENDA blend of whiskies manufactured in Scotland in compliance with the laws of the United Kingdom
IRISH WHISKEY Unblended whiskey manufactured in the Republic of Ireland or in Northern Ireland in compliance with their laws
BLENDED IRISH WHISKEY OR IRISH WHISKEY – A BLEND A blend of whiskies manufactured in the Republic of Ireland or in Northern Ireland in compliance with their laws
CANADIAN WHISKEY Unblended whiskey manufactured in Canada in compliance with its laws
BLENDED CANADIAN WHISKEY OR CANADIAN WHISKEY – A BLEND A blend of whiskies manufactured in Canada in compliance with its laws
