125th Anniversary Review: The Role of Hops in Brewing

Abstract

Although hop technology has been a substantial part of brewing science for the last 130 years, we are still far from claiming to know everything about hops. As hops are considered primarily as a flavour ingredient for beer, with the added benefit of having anti‐microbial effects, hop research is focused on hops as a bittering agent, as an aroma contributor and as a preservative. Newer fields in hop research are directed toward the relevance of hops in flavour stability, brewing process utilisation, the technological benefits of hops in brewing as well as hops as a source of various substances with many health benefits. However the more we find out about the so‐called “spirit of beer” the more questions emerge that demand answers. While hop research was only an ancillary research field for decades, during the last ten years more universities and breweries have determined that hops must play a meaningful role in their research efforts. This article gives an overview of the up‐to‐date knowledge on hop aroma, hop derived bitterness, and the role of hops in flavour stability as well as light stability. Hop research is a wide field, therefore in this review only selected topics are reviewed. Other research areas such as hops utilisation, the antifoam potential of hops, or the advances in knowledge pertaining to the physiological valuable substances of hops go beyond the scope of this article.

Modification of perceived beer bitterness intensity, character and temporal profile by hop aroma extract

“…Of the four main brewing ingredients (water, malted barley, yeast and hops) hops (Humulus lupulus L.) re-main an essential flavour ingredient in beer (Schönberger & Kostelecky, 2011). Hop resins and essential oils, located within the lupulin glands of the female hop flowers are the sources of bitterness and aroma characters in beer, respectively (De Keukeleire, 2000; Opstaele, Goiris, De Rouck, Aerts, & De Cooman, 2012b).…”

Creativity, Community, & Growth: A Social Geography of Urban Craft Beer

“…In addition to different hop varieties craft breweries also use different hopping regimes that impact the flavor/aroma profile of their beer. Thus by adding hops at different stages of the brewing process (dry-hopping versus late-hopping) quite distinctive flavor/aroma profiles can be obtained (Schönberger, Kostelecky 2011). A number of craft brewers also engage in the practice known as wet-hopping which involves adding fresh hops (as opposed to say pelletized hops) that are delivered to the brewery within 48 hours of being picked (Vandenengel 2014).…”

“…A number of craft brewers also engage in the practice known as wet-hopping which involves adding fresh hops (as opposed to say pelletized hops) that are delivered to the brewery within 48 hours of being picked (Vandenengel 2014). The plethora of hop varieties and the choice of different hopping regimes has been the catalyst for considerable creativity among craft brewers and have been credited with promoting new scientific research related to hops (Schönberger, Kostelecky 2011).…”

Alternative Methods for Shelf Life Extension of Unfiltered Beers from Microbreweries

“…Jedná se například o v poslední době velmi populární studené chmelení, během kterých jsou do piva přidávány další suroviny či minimálně používané high gravity brewing (Schönberger a Kostelecký, 2011).…”

“…During this process, further hops are added. High gravity brewing is seldom used in microbreweries (Schönberger and Kostelecký, 2011). However, these procedures bring an increased risk of microbial contamination and subsequently a decrease in sensorial stability.…”