unit 4 lesson 6

Question 1

What is the typical mass range of hop bales?

Answer 1

60-80 kg

Question 2

What bulk density can cause rupture of the lupulin glands?

Answer 2

More than 150 kg/m3

Question 3

Why are hop bales stored in cold rooms?

Answer 3

To reduce the rate of loss of soft resins and essential oil components.

Question 4

What is a major disadvantage of whole hops in brewing?

Answer 4

They go stale more rapidly than other hop products.

Question 5

What is the typical hop utilisation rate for whole hops?

Answer 5

As low as 10%

Question 6

What are the two sub-categories of whole cone hops?

Answer 6

• Dried whole hops
• Fresh/green whole hops

Question 7

What is the primary use of dried whole hops?

Answer 7

For either bittering or aroma.

Question 8

What is the average moisture content of whole dried hops?

Answer 8

10%

Question 9

What is an advantage of using whole hops?

Answer 9

Most natural and unprocessed.

Question 10

What is a disadvantage of using dried whole hops?

Answer 10

They are bulky and expensive to store.

Question 11

What are T100 hop pellets?

Answer 11

Compressed plugs of whole cone hops, used for easier and consistent addition of hops.

Question 12

What characterizes fresh/green whole hops?

Answer 12

They are harvested fresh and can only be used once per year.

Question 13

What is the main application of T90 hop pellets?

Answer 13

For either bittering or aroma.

Question 14

What does T90 stand for?

Answer 14

Type-90, meaning about 90% of the original bale mass ends up in the pellet.

Question 15

What is the average moisture content of T90 hops?

Answer 15

6%

Question 16

What is a significant advantage of T90 hop pellets over whole hops?

Answer 16

Better hop utilisation (27-32%).

Question 17

What are T45 hop pellets known for?

Answer 17

Higher resin and essential oil content, nearly double that of T90 pellets.

Question 18

What is a disadvantage of T45 hop pellets?

Answer 18

They can contain fertilisers and pesticides.

Question 19

What is the purpose of the BBC Pure Hop Pellet™?

Answer 19

Designed to be more suitable for dry hopping than T90s.

Question 20

What are Cryhops® and CGX™?

Answer 20

New versions of hop pellets made using liquid nitrogen.

Question 21

What are the two main solvents used for hop extraction?

Answer 21

• Ethanol
• Carbon dioxide (CO2)

Question 22

What is ethanol’s main characteristic as a solvent?

Answer 22

Soluble in water and polar.

Question 23

What does carbon dioxide extraction excel at?

Answer 23

More selective extraction of specific hop compounds.

Question 24

What does ethanol hop extract primarily contribute to?

Answer 24

Bittering, although essential oils can contribute to aroma.

Question 25

What is the primary use of ethanol hop extract?

Answer 25

Used primarily for bittering ## Footnote Essential oils can also contribute to aroma.

Question 26

What are the two types of CO2 solvents used to make hop extracts?

Answer 26

* Liquid CO2 * Supercritical CO2

Question 27

What is a significant advantage of CO2 hop extract over ethanol hop extract?

Answer 27

CO2 extraction is more selective, removing less water soluble compounds.

Question 28

What is the average total resins percentage in liquid CO2 hop extract?

Answer 28

70-95%

Question 29

What is isomerised hop pellets' utilisation rate?

Answer 29

Around 65%

Question 30

What catalyst is used to isomerise hop pellets?

Answer 30

Magnesium oxide

Question 31

What is the key difference between isomerised hop extract (IKE) and potassium isomerised kettle extract (PIKE)?

Answer 31

IKE uses magnesium salts, while PIKE uses potassium salts.

Question 32

What is the typical concentration of iso-α-acids in iso-extract?

Answer 32

Around 30%

Question 33

What is the main disadvantage of iso-extract?

Answer 33

It only adds bitterness, not aroma.

Question 34

What compound causes the lightstruck flavor in beer?

Answer 34

3-methyl-2-butene-1-thiol (3-MBT)

Question 35

What is the threshold for detecting 3-MBT in beer?

Answer 35

4-7 ng/L

Question 36

What type of hop extract is produced using sodium borohydride as a hydrogenation agent?

Answer 36

Rho-hydro iso-extract

Question 37

How many hydrogen atoms are added during the production of tetra-hydro iso-extract?

Answer 37

Four

Question 38

What is a key advantage of reduced hop extracts?

Answer 38

They provide light stability.

Question 39

What is the typical concentration of rho iso-extract?

Answer 39

30%

Question 40

What is the main purpose of hop aroma products?

Answer 40

To add hop aroma to beer

Question 41

What are the typical addition points for hop aroma products?

Answer 41

* End of boil/whirlpool * Fermentation/maturation

Question 42

What is the composition of ethanol hop extract compared to whole hops regarding essential oil?

Answer 42

0-5%

Question 43

True or False: Ethanol hop extract contains more polyphenols than whole hops.

Answer 43

False

Question 44

What are the two main timing points for adding hops to beer for aroma?

Answer 44

End of boil/whirlpool for late hop aroma and fermentation/maturation for dry hop aroma. ## Footnote Dosing at the start of the boil is less common due to aroma loss.

Question 45

What are hop oil products typically produced from?

Answer 45

Ethanol or CO2 extracts by steam and vacuum distillation, thin film evaporation, CO2 fractionation, or chromatography. ## Footnote They can also be made by steam distillation of uncompressed dried hop cones.

Question 46

How does the distillation process separate components of hops?

Answer 46

By their volatilities, using heat to evaporate specific components at their boiling points. ## Footnote Lower pressure in a vacuum still reduces the boiling point temperature.

Question 47

What is the purpose of adjusting conditions during CO2 fractionation?

Answer 47

To change the polarity of CO2 and affect the nature of the molecules dissolved in it. ## Footnote This allows separation of polar and non-polar molecules.

Question 48

What are the benefits of using hop oil products?

Answer 48

They provide different aroma and taste compared to hop pellets and whole hops. ## Footnote Combining pellets or whole hops with oil products achieves the dry hop character.

Question 49

What is Barth Haas SPECTRUM made from?

Answer 49

CO2 extract formulated for direct addition after dispersal in deoxygenated water. ## Footnote It uses a secret component of hop extract as emulsifier.

Question 50

What are antimicrobial hop products derived from?

Answer 50

β-acids, effective against Gram-positive bacteria like Lactobacillus and Pediococcus. ## Footnote They are dissolved in alkaline solutions due to poor solubility.

Question 51

What is the function of antifoam products in brewing?

Answer 51

To act as an antifoam agent in both the kettle and fermentation vessel. ## Footnote They are derived from lipids and waxes extracted from hops.

Question 52

What does tannin extract contain and what is its use?

Answer 52

Polyphenols that can be added back if required. ## Footnote It is derived from the water-soluble fraction of the ethanol extraction process.

Question 53

What are some recommended hop merchant websites to find new products?

Answer 53

* Hopsteiner * Barth-Haas * Totally Natural Solutions * Crosby Hops * Yakima Chief Hops * Kalsec ## Footnote These suppliers regularly update their product offerings.

Question 54

Fill in the blank: The most common point for dosing hops is after _______.

Answer 54

fermentation.

Question 55

True or False: The β-acids help prevent foam formation in the kettle.

Answer 55

True.

Question 56

What should you be able to identify after this lesson regarding hop products?

Answer 56

The appropriate hop product for a specific beer. ## Footnote This includes understanding their effects and manufacturing processes.