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.
Suggested Response - Q3
** Your hop merchant has invited you to come and select a batch of hops of your preferred high α-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.
Response:
The brewer should assess the hops both physically and analytically. One of the key points is that it is a high α-acid variety (used for solely bittering) and hence aroma analysis is not relevant, with the exception of confirming the absence of ‘off-flavours’.
The physical examination should cover the following characteristics:
- Colour – this should be typical for variety, but generally green in colour; check for any colour discolouration.
- Lupulin – check that the lupulin glands are big, fat and yellow glands. Small, thin glands may be low alpha hops. A deep orange colour may suggest oxidation or too much heat in the kiln.
- Mould – there should be no mould. Any mould would suggest aphids or poor storage.
- Cone damage – the cones should be whole (in general), and not broken up.
- Moisture – the hops should be a bit ‘oily’ from the lupulin, and not excessively dry.
- Size – should be in line with expectation for that variety. Abnormal sizing may suggest disease.
- Pests/Disease – check for any signs of pest or disease damage:
- Red discolouration – may be due to spider mite.
- Black discolouration – mould due to aphids.
- Silver/brown spots – mildew.
- Seed and leaf-stem content – ensure these are kept to an absolute minimum.
- Aroma – ensure no ‘off flavours’, such as ‘cheesy’ or ‘musty’. Since this is not an aroma variety, the breakdown of the aromas is not important, but you do need to check for ‘off-flavours’.
Analytically, the key point is seeing the α-acid content. It would be good to mention that there are different methods, namely LCV, HPLC or spectrophotometry that can be used to measure the α-acid content; you would expect at least one of these methods to be used. You would ideally HPLC as it is the most accurate method. Discussing the essential oil content is not relevant to this question.