Lesson 9 - Brewing with Hops SAQ
This lesson allows you to test yourself on the material covered in the previous lesson, Brewing with Hops, and determine the level to which you have attained the outcomes.
Self-Assessment Questions
1. *Define what an IBU is and provide an overview of how it is measured.
2. *Write short answers to the following questions:
a) Name four hop points of addition and say what the primary impact on hop flavour in the finished beer will be.
b) What is a hopback, and what is its purpose?
c) List five factors that can influence the efficiency of extracting the essential oils during dry hopping.
d) What temperatures should hop extracts and pellets be kept at during automatic dosing?
e) What does LCV stand for? Provide a description of the method, including a diagram to show how the LCV value is read.
3. ** Your hop merchant has invited you to come and select a batch of hops of your preferred high a-acid variety. They are providing four different Lots (batches) for you to examine. Explain how you would select which Lot is the best for you and what you would be looking for.
4. ** Your recipe for a beer with an IBU of 19, states that 10 kg of aromatic hops (with 5% a-acid) are added 15 mins before the end of boil in a 1000 hL brew. The hop utilisation towards the end of the boil is 8%; at the start of the boil it was 30%.
a) Calculate the quantity of 15% a-acid hops that should be added at the start of the boil.
b) As an experiment, the beer was dry hopped. At the end, it was found to have 13 mg/L of humulinone and 10 mg/L of a-acid in addition to the iso-a-acid. What is the calculated bitterness of this beer?
5. **200 hL of Brand A is brewed at high gravity. There are two hop products used to make the beer, a CO2 hop extract with an a-acid content of 40% and T90 pellets with an a-acid content of 10%. Both hop products are added at the start of boil, with 2 kg of CO2 extract added and 10 kg of T90 pellets being added.
The wort kettle has an overall hop utilisation of 50%. The brewery encounters an overall bitterness loss throughout the brewing process of 30%.
The beer is diluted from 7% to 5% ABV before packaging.
Determine the in-package IBU.