Non-Isomerised Hop Extract Flashcards
What is extraction in the context of hop material?
The removal of specific compounds from solid hop material using a solvent.
Which two solvents are currently used for hop extraction?
Ethanol and carbon dioxide (CO2).
Why are ethanol and CO2 favored for hop extraction?
Both are found in beer and are considered safe for human consumption.
What is the main characteristic of ethanol as a solvent?
Ethanol is soluble in water and polar.
How does CO2 differ from ethanol in terms of solubility?
CO2’s solubility changes with temperature and pressure and is less polar.
What type of solutes dissolve best in polar solvents?
Polar solutes like salts.
What does ethanol extraction tend to extract more of compared to CO2 extraction?
More of the original hop compounds like hard resins and polyphenols.
What compounds does ethanol hop extract contain?
Soft and hard resins, essential oils, and polyphenols.
What is the primary application of ethanol hop extract?
Used primarily for bittering.
What are the advantages of ethanol hop extract compared to whole hops?
[“High concentration of bitter substances”, “Natural solvent”, “Similar composition of bitter and aroma compounds”, “Reduced nitrate and pesticide levels”, “Less storage space required”, “Good shelf life”, “Improved utilisation (35-40%)”, “Minimal wort/beer losses”, “Contains hard resins like xanthohumol”, “Can be free of polyphenols”]
What is a disadvantage of using ethanol hop extract?
Small amount of solvent residue (ethanol).
What is a key feature of CO2 in the context of hop extraction?
CO2 can be compressed into a liquid to act as a solvent.
What are the two types of CO2 used for hop extraction?
Liquid CO2 and supercritical CO2.
At what pressure and temperature is liquid CO2 used?
50 bar and 10-15°C.
What are the extraction efficiencies of liquid CO2 compared to supercritical CO2?
Liquid CO2 has lower overall extraction efficiency than supercritical CO2.
What is the main advantage of supercritical CO2 extraction?
It is more selective, removing less water soluble compounds.
What is a benefit of CO2 as a solvent?
Oxidation does not occur during extraction.
What is the typical α-acid concentration when using CO2 extraction?
Usually around 30%.
What is a disadvantage of CO2 hop extracts?
Cost per unit of α-acid is higher than whole cone hops or pellets.
What are iso-α-acids in the context of hop usage?
Key compounds for bittering in beer.
What process traditionally produces iso-α-acids from α-acids?
Takes time and heat in the kettle.
What is the potential benefit of isomerised hop products?
They could significantly increase utilisation and reduce variation in beer bitterness.
