Dry Hopping Flashcards
What is dry hopping?
The addition of hops, or hop products, after wort cooling.
What factor affects the effectiveness of dry hopping related to particle size?
Smaller particles that are well dispersed give up their aroma compounds easier than larger particles.
How does the condition of lupulin glands affect dry hopping?
Chopping hop cones into tiny particles disrupts the lupulin gland, making essential oils dissolve less readily.
What effect does temperature have on dry hopping extraction?
Higher temperatures increase energy, driving dissolution and diffusion, leading to faster extraction.
At what temperature does hop plant material not swell, significantly reducing extraction rates?
0°C
How does the concentration gradient influence extraction rates during dry hopping?
A high concentration of the compound in beer leads to low extraction rates, while a lower concentration allows for faster extraction.
What is the relationship between contact time and dry hop flavor extraction?
There is an optimum contact time for extraction, as different oils are extracted and decline in concentration at different rates.
How does alcohol concentration generally affect extraction rates in dry hopping?
Higher alcohol concentration typically increases extraction rates.
What happens to the extraction efficiency of aroma compounds at high hop addition rates?
The extraction efficiency declines with higher hop addition rates.
What are process losses in dry hopping?
Loss of essential oil components that are sparingly soluble, which can stick to hop plant material, yeast cells, or filters.
What role does yeast play during dry hopping?
Yeast can remove flavor compounds by sticking to them and also biotransform them.
What enzyme products can be added to release aroma compounds during dry hopping?
Bacterial β-glucosidase and β-lyase.
What is the importance of flushing vessels and lines with CO2 before dry hopping?
It reduces the level of oxygen in the hops and equipment, thereby reducing beer oxidation.
What are the two main categories of dry hopping methods?
Static and dynamic methods.
What distinguishes dynamic dry hopping methods?
They use agitation or recirculation to help extract flavor compounds.
What is in-tank dry hopping?
Adding hops to the fermentation or maturation vessel before or after filling.
What is the advantage of using pellets in in-tank dry hopping?
Pellets disperse throughout the beer, providing better extraction.
What is the method of dry hopping in a separate vessel?
Hops are added to an extraction vessel before beer is pumped through it and back into the process vessel.
What is cask conditioning?
Secondary fermentation in the package, where unfiltered beer contains a set concentration of yeast.
How do large breweries typically add hop oil products?
Using a hop dosing vessel, a flow meter, and a pump, dosing in-line upstream of a static mixer.
What is the risk of adding iso-extract and reduced hop extract after filtration?
Haze may form since some products are not completely soluble.
