Finishing and Packaging Flashcards
Define clarification
all the processes, physical and chemical, that are used to make wine clear
What is precipitation
When suspended matter precipitates, it means that solid particles previously dispersed in a liquid (like water) are now coming out of the solution as a solid, forming a precipitate.
what is a precipitate
a solid formed by a change in a solution, often due to a chemical reaction or change in temperature that decreases solubility of a solid
Give three reasons as to why a substance precipitates.
Decreased Solubility: If the concentration of a substance in the solution increases beyond its solubility limit
Chemical Reaction: A chemical reaction between two dissolved substances
Changes in Conditions:
temperature, pH, or the presence of other substances
what is suspended matter
any particles that are not fully dissolved or are held in suspension within the liquid.
These particles can include dead yeast cells (lees), bacteria, tartrates, proteins, pectins (starch), tannins, and other compounds,
what is fining?
Fining is a procedure in which a fining agent is added to speed up the process of the precipitation of suspended material in the wine
what are unstable colloids
microscopic particles too small to be removed by filtering
difference between adsorption and absorption
Adsorption refers to the adhesion of molecules to the surface of a material, while absorption involves the penetration of molecules into the bulk of a materia
what are the two bases for bentonite?
calcium and sodium
What particles are contained in unstable colloids
particles that that include proteins, phenolics (tannins and anthocyanin), and polysaccharides (pectin/complex carbohydrate) PPP***
fining agents helps to;
- clarify and stabilize (against the future formation of hazes)
- removal of harsh tannins
- browning in white wines.
what is filtration
physical separation technique used to eliminate solids from a suspension by passing it through a filter medium consisting of porous layers that trap solid particles, thus making the liquid clear
What is a suspension
refers to small particles of solids that are not dissolved but are dispersed throughout the liquid,
Define depth filtration
method of filtration traps particles in the depth of the material that forms the filter
Define Surface filtration
surface filter stops particles that are bigger than the pore size of the filter from going through. They are often termed absolute filters
What is a lenticular filter and what are the benefits?
modern sheet filter
- filter elements are contained in a cylindrical stainless steel housing
- improves hygiene & regeneration of filter material
describe the benefit of cross flow filters
- compared to other methods;
- flow of liquid is perpendicular to the surface of the filter (solid particles collect on surface, gradually blocking)
- flow is parallel to surface so cross flow keeps membrane surface clea
