Harvest ale is not a defined style or class of beer, but rather is marketing term and common name for many different beers.
[1] The tagline generally refers to beers being brewed for fall harvests.
This most commonly refers to the hop harvest but can also be connected with grain harvest, Oktoberfest, or as a general term for fall seasonal beers.
This beer or brewery-related article is a stub.
You can help Wikipedia by expanding it.