Aroma variations of mid-Atlantic hops driven by growing regions and postharvest practices

Hop (Humulus lupulus L.) is an indispensable raw material with unique bitterness and pleasant aroma in the brewing industry. Recently, hop has become an emerging specialty crop in Mid-Atlantic regions due to the unprecedented development of the craft brewing. However, the aroma characteristics of these region-specific hops are not yet available. This study explored the aroma profiles of hops harvested from multiple mid-Atlantic locations and experienced various postharvest practices by use of headspace-solid-phase microextraction-gas chromatography-mass spectrometry-olfactometry (HS-SPME-GC-MS-O). Results showed that β-myrcene, geraniol, linalool and methyl octanoate with respective herbal, citrus and floral notes were predominant compounds in all fresh and dried hops. Fresh Cascade and Chinook from Meadowview contained significantly higher concentrations for most aroma compounds comparing to the ones harvested from other locations. Dehydrator drying could effectively preserve aroma compounds in both varieties, especially when compared to oven drying. Additionally, freeze-drying maximally retained the original hop colour.