Columbus, CTZ (Columbus, Tomahawk, Zeus), and Zeus are terms used interchangeably to refer to a hop variety that is a high-alpha acid hop known for its bittering properties. While they are sometimes considered distinct varieties, they are often grouped together due to their similar lineage and characteristics.

Here are some key features of Columbus/CTZ hops:

1. Flavor Profile: Columbus hops are primarily used for bittering, and they contribute a clean, pungent, and resinous bitterness to beer. They are not as commonly used for their aroma, but they can impart earthy, spicy, and sometimes citrus notes.
2. Alpha Acids: Columbus/CTZ hops are known for their high alpha acids content, making them particularly suitable for providing bitterness in brewing. The alpha acids content can range, but it is generally on the higher side.
3. Usage: These hops are commonly used in the early stages of the boil to achieve the desired bitterness in the beer. They are frequently employed in hop-forward beer styles such as American Pale Ales (APAs) and India Pale Ales (IPAs), where a bold and assertive bitterness is desired.
4. Aroma: While Columbus/CTZ hops are not typically chosen for their aroma, some brewers may utilize them in late hop additions or dry hopping to extract subtle earthy, spicy, or citrus aromas.
5. Origin: The exact origins of Columbus/CTZ hops can be a bit complex. They are often considered synonymous and are thought to be a result of hybridization involving a mix of Nugget, Zeus, and a USDA male. The variety was first bred in the 1970s.
6. Dual Purpose: While primarily known for their bittering properties, Columbus/CTZ hops are considered dual-purpose hops because they can contribute both bitterness and some aroma. However, their primary use is often for bittering.

Brewers appreciate Columbus/CTZ hops for their reliable bittering qualities and their ability to add a resinous and pungent character to beers. They are frequently used in combination with other hop varieties to create well-balanced and hop-forward brews.