Lesson 7 - Hop Products SAQ
This lesson enables you to test yourself on the material covered in Lesson 6 on Hop Products and determine to what level you have attained the outcomes.
Suggested Response - Q1
*Arrange the following in order of utilisation efficiency, from highest to lowest, giving reasons why:
a) T90 hop pellet.
b) Isomerised hop extract (Post Fermentation Bittering).
c) CO2 hop extract.
d) Isomerised kettle extract.
e) T45 hop pellet.
f) Isomerised hop pellet.
Response:
From highest to lowest: Isomerised hop extract > isomerised kettle extract > Isomerised hop pellet > CO2 hop extract > T45 Pellets > T90 Pellets. Reasoning is as follows:
I. Isomerised hop extract (PFB): these are added post fermentation and thus incur fewer losses as they are not lost in trub, yeast cells or fobbing. PFB’s achieve over 90% utilisation.
II. Isomerised kettle extract: some losses will occur as bittering compounds adhere to trub. There will also be losses from yeast cells and fobbing as well as filtration. Utilisation is around 70%.
III. Isomerised hop pellet: similar to Isomerised kettle extract, but losses will be higher due to solid material being more likely to be lost with trub, and pellets are less soluble than extract. Utilisation is around 65%.
IV. CO2 hop extract: although losses will occur due to isomerisation loss during the boil, and process losses as described in the examples above, this extract is more soluble than pellets and thus will be utilised slightly better. Utilisation is around 40%.
V. T45 Pellets: also not isomerised, so not as effective as isomerised products. The hop material is more concentrated than the T90 pellet and so will be more efficient. Losses will occur due to less solubility than extract and the usual process losses. Utilisation is around 35%.
VI. T90 pellets: difficult to solubilise the α-acid content and to then isomerise, plus there will be the various process losses already described. Utilisation is around 30%.