The green brewer's gold

When you say beer, you say hops

Hops contain substances that are not found in other plants, such as alpha acids (humulones) and beta acids (lupulones), and isoalpha acids. These compounds not only contribute to the bitterness and flavour of the beer but also have antibacterial properties that help preserve the beer by inhibiting the growth of certain bacteria.

Hops also contain some volatile compounds, such as essential hop oils. These oils determine the taste and aroma of the beer and are therefore crucial for the beer experience. There are also non-volatile compounds, such as hop polyphenols. Although some of these substances are also found in other plants, the qualitative (which substances) and quantitative (how much) composition is different for each hop variety! This means that the aroma (essential hop oils) and the health benefits (hop polyphenols) are specific to each individual hop variety.

Furthermore, hops aid in the clarification of beer by precipitating proteins and are essential for a stable foam head due to the presence of certain compounds in hops, such as humulones. These compounds help to retain the bubbles in the foam and prevent the foam from collapsing quickly. Despite all the benefits, our super plant also has its challenges. Exposure to light can cause a "skunky" or "light-struck" flavour, and during storage, it can create an "oxidized" or "cardboard" flavour.

Hop Oil 

While alpha and beta acids are identical in all hop varieties, the aromatic components differ in each hop variety. This gives brewers a world of possibilities to get creative with. There are a few key components of hop oil that we'll briefly zoom in on: terpenes such as myrcene, humulene, caryophyllene, and farnesene. 

  • Myrcene
    This is one of the most common terpenes in hop oil and has an earthy, spicy aroma. It can also add fruity and floral notes to the beer. 
  • Humulene
    Contributes to the hoppy and spicy aromas of hops. It can also give a slight bitter taste to the beer and is sometimes associated with woody and grassy notes.
  • Caryophyllene
    This terpene has earthy, spicy, and peppery tones. It can add a spicy taste to beer and is often associated with clove-like aromas.
  • Farnesene
    Contributes to the floral and citrusy aromas of hops. It can also add a slight spiciness to the beer and is often associated with fruity and grassy tones.

You'll find these terpenes and their percentages listed for each hop variety in our hop guide! 

 Hop Techniques 

During the boiling of the wort, iso-alpha acids are formed from the alpha acids, naturally present in hops. Alpha acids are converted into iso-alpha acids when they are heated in the wort. This reaction, known as isomerization, is responsible for the bitterness of your beer.

In addition to the formation of iso-alpha acids, processes occur during boiling that lead to the loss of volatile hop aromas. The high temperatures during boiling cause these volatile aromatic compounds to evaporate, unfortunately resulting in the loss of much of the hop aroma. This loss of aroma is not unfamiliar to most brewers. It is one of the reasons why brewers choose to add hops at different times during brewing, particularly during the final part of boiling or even after boiling during dry-hopping.

By combining different techniques, brewers can achieve bitterness by forming iso-alpha acids during boiling, while retaining volatile hop aromas by adding them at times when the wort is no longer exposed to high temperatures. Below is a handy overview:

Bitter Hopping
This is the most common way to add hops during the brewing process. Bitter hopping usually occurs during the boiling of the wort. The aim is to increase the bitterness of the beer by adding hops during boiling. The hops are added to the boiling wort for an extended period (usually 60-90 minutes) to extract the desired bitterness.

Aroma and Flavour Hopping
This involves adding hops later in the boiling process, typically in the final 15 minutes of boiling or even after boiling, during wort cooling. This mainly preserves the aroma and flavour properties of the hops while extracting less bitterness. This contributes to the aroma and flavour profiles of the beer.

Dry Hopping
This is the addition of hops to the beer after fermentation is complete and the beer is cooled. The hops remain in contact with the beer for a certain period (usually several days to several weeks), adding aromas without producing additional bitterness. Dry hopping is especially popular in beers that aim for strong hop aromas, such as IPAs (India Pale Ales).

Hopbacking
This is a technique where wort is pumped through a vessel containing hops after it has been boiled and before it is cooled. This enriches the wort with hop aromas before it is cooled and fermented.

Hopstand
This is a technique where hops are added to the wort after boiling is complete and before it is cooled. The wort remains at a high temperature for a certain period (usually 20-30 minutes) while hops are added. This helps in extracting additional hop aromas and contributes to the complexity of the beer.

Whirlpool hopping
This is a technique where hops are added to the wort after boiling and before cooling. The wort is brought into a whirlpool where hops are added and allowed to rest for a certain period.

View our range of hops
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