Lesson 4 - Hop Chemistry
Hop Chemistry Overview
The word chemistry can cause some discomfort to most of us. However, we need to understand some of the scientific terms to better understand how hop compounds can affect the brewing process and beer flavour.
As we learnt in Hop Lesson 2, the hop cone is made up of the following.
Table: Chemical composition of whole hops
|
Constituent |
Amount (% w/w) |
|
Lipids |
2-5 |
|
Total resins |
15-30 |
|
α-acids |
2-18 |
|
β-acids |
2-14 |
|
Essential oil |
0.5-3 |
|
Proteins |
15 |
|
Monosaccharides |
2 |
|
Polyphenols |
4 |
|
Pectins |
2 |
|
Amino acids |
0.1 |
|
Waxes and sterols |
Trace |
|
Ash |
8 |
|
Moisture |
10 |
|
Cellulose, etc. |
43 |
We also learnt that the key components of hops are the polyphenols, total resins and essential oils. We know that lupulin glands are found in the hop cone, and that lupulin contains the total (hard and soft) resins and essential oils. We also know that the polyphenols come from the bracts and bracteoles of the hop cone.
The figure below shows the components of hop cones. We refer to this and build on it as the lesson continues.
Figure: Hop components