Clarification Flashcards
(24 cards)
What is the primary focus of wine clarification through physical filtration?
Removing solid particles and microorganisms.
How are filtration methods categorised?
Based on their mechanism and the equipment used.
What are the two main mechanisms of filtration?
- Surface screening
- Depth capture
What factors influence the choice of filtration method?
- Characteristics of the liquid (e.g., turbidity, particle size distribution)
- Filter media selection
- Operating parameters
List the hierarchy of filtration methods from coarser to finer.
- Lees
- Clarification
- Polishing
- Sterile
What is the role of size in particle removal during filtration?
Different filtration methods with varying pore sizes are required to remove specific components.
What is Diatomaceous Earth (DE) used for in filtration?
Forms a matrix of spaces to trap solids.
What is a key characteristic of Perlite as a filter media?
It is expanded volcanic glass with low density.
What is the purpose of Rotary Drum Vacuum (RDV) filters?
Recovering wine from high solids mixtures.
How does the RDV filter mechanism work?
A screened drum with a vacuum draws filter media onto the screen.
Describe the main feature of Lees Filters.
Old technology for lees recovery using a coarse cloth based filter.
What are Earth Filters primarily used for?
Utilising pressure to force wine through a cake of filter media.
What is a significant disadvantage of Earth Filters?
Spent filter media is messy and generates large volumes.
What types of filtration are used for fairly clarified wine/juice?
- Lenticular cartridges
- Pad filters
What are the three methods of solids capture in depth filtration?
- Surface screening/sieving
- Depth capture
- Electrostatic charge
What characterises Type 1 failure in depth filters?
Increasing back pressure and decreasing flow rate.
What is membrane filtration primarily used for?
Guaranteeing sterility.
What is a characteristic of cross flow filtration?
The flow of liquid is tangential to the filter membrane.
What are the two streams produced by reverse osmosis?
- Permeate
- Retentate
What are some applications of reverse osmosis in wine production?
- Increasing sugar levels
- Concentrating flavour and colour components
- Decreasing alcohol levels
- Reducing faults
What is an advantage of RDV filters?
Can provide high clarified liquid.
What is a disadvantage of Earth filters?
Can have negative organoleptic properties.
What is a key disadvantage of depth filter - pad?
Slow and not useful for high turbidity liquid.
What is a disadvantage of depth filter - lenticular cartridge?
More expensive than pads.
