Definition - What does Fining mean?
When fining is done correctly, the end results is a clear, crisp wine of superior quality; however, there are risks associated with fining, such as the removal of the aromatic or flavor profile of the natural grape variety, removing the natural nutritional elements. For this reason, some winemakers don’t use fining agents at all or they delay the fining process until the last second.
Fining is also known as clarification.
WineFrog explains Fining
There are four main ways for a fining agent to bind with the soluble substance:
Electrostatic - the most common way for a fining agent to bond with the substance, electrostatic bonding is when the fining agent has an opposite charge than the substance. Opposite charges attract, and the two particles bind together as a stable compound that separated from the wine as a floating or settled mass. These types of fining agents are used to remove proteins, tannins and coloring particles.
Ionic - similar to electrostatic bonding, ionic bonds occur when opposite charges attract. However, the ionic bond require additional fining agents to remove them from the wine.
Adsorbent/Absorbent - the fining agents act as a magnet. The substance attaches to the surface of the agent (adsorbent) or is swallowed/absorbed by the agent (absorbent). Activated carbons and specialized fining yeasts are the only types of adsorbent fining agents.
Enzymatic - a biological bonding, fining agents and the negative substances bind together to create a new molecule. The two enzymatic fining agents are pectin and pectinase. They remove the soluble substances that cause the hazy appearance of wines and juices. They are also the few types of fining agents that can be added prior to fermentation.