Clarification and Stabilization of Wine - Clarifying Wine - Fining


In winemaking, fining is the process where a substance (fining agent) is added to the wine to create an adsorbent, enzymatic or ionic bond with the suspended particles, producing larger molecules and larger particles that will precipitate out of the wine more readily and rapidly. Unlike filtration, which can only remove particulates (such as dead yeast cells and grape fragments), fining can remove soluble substances such as polymerized tannins, coloring phenols and proteins; some of these proteins can cause haziness in wines exposed to high temperatures after bottling. The reduction of tannin can reduce astringency in red wines intended for early drinking. Many substances have historically been used as fining agents, including dried blood powder, but today there are two general types of fining agents — organic compounds and solid/mineral materials.

Organic compounds used as fining agents are generally animal based, a possible cause of concern to vegans. The most common organic compounds used include egg whites, casein derived from milk, gelatin and isinglass obtained from the bladders of fish. Pulverized minerals and solid materials can also be used, with bentonite clay being one of the most common, thanks to its effectiveness in absorbing proteins and some bacteria. Activated carbon from charcoal is used to remove some phenols that contribute to browning as well as some particles that produce "off-odors" in the wine. In a process known as blue fining, potassium ferrocyanide is sometimes used to remove any copper and iron particles that have entered the wine from bentonite, metal winery and vineyard equipment, or vineyard sprays such as Bordeaux mixture. Because potassium ferrocyanide may form hydrogen cyanide its use is highly regulated and, in many wine producing countries, illegal. Silica and kaolin are also sometimes used.

Some countries, such as Australia and New Zealand, have wine labeling laws that require the use of fining agents that may be an allergenic substance to appear on the wine label. A study conducted by the University of California, Davis Department of Viticulture and Enology, however, found that no detectable amount of inorganic fining agents, and only trace quantities of proteinaceous agents, are left in the wine.

There is the risk of valuable aromatic molecules being precipitated out along with the less desirable matter. Some producers of premium wine avoid fining, or delay it in order to leach more flavor and aroma from the phenols before they are removed.

Read more about this topic:  Clarification And Stabilization Of Wine, Clarifying Wine

Other articles related to "fining":

Red Wine - Production - Fining and Stabilization
... Red wines sometimes undergo fining, which is designed to clarify the wine and sometimes to correct faults such as excess tannin ... Fining agents include egg white and gelatine ...
Finery Forge - History
... The fining process involved liquifying cast iron in a fining hearth and removing carbon from the molten cast iron through oxidation ... Wagner writes that in addition to the Han Dynasty hearths believed to be fining hearths, there is also pictoral evidence of the fining hearth from a Shandong tomb mural dated 1st to 2nd century AD ...
Funtley - Fontley Iron Mills
... Cort's innovation was a new process for "fining" iron ... for forging (though it could be cast ) fining removed the impurities ... The previous method of fining used a finery hearth fuelled with charcoal ...
Winemaking - Blending and Fining
... Fining agents are used during winemaking to remove tannins, reduce astringency and remove microscopic particles that could cloud the wines ... The winemakers decide on which fining agents are used and these may vary from product to product and even batch to batch (usually depending on the grapes of that particular year) ... for centuries and is recognized as a traditional method for wine fining, or clarifying ...