Reviewers often mention how the beer's profile shifts dramatically depending on how long you let it sit.
Reviewers from BeerAdvocate and Pat's Pints highlight its distinctive characteristics:
Just had my very first Orval and it's the strangest beer I have ever had.
Because it is bottled with Brettanomyces yeast, it develops a signature "barnyard" or hay-like funkiness over time.
Manchester Drainage