Finings – Ian Hickinbotham
Clear as crystal
By Ian Hickinbotham
Finings have been used to clarify wine for hundreds of years.
When first made, new wine can have the density of pea soup, depending mainly on how aggressive the pressing of the grape skins has been during vinification. Finings are agents used to remove the suspended organic compounds and thus to make the wine clear.
Different grapes contain varying amounts of natural proteins and other matter that are suspended in new-made wine. Further, the more natural acidity in such wine, the clearer it is, so generalising, Riesling wine is always comparatively clear, which is why it can be bottled when very young, thereby protecting against undesirable loss of the wine’s lovely aroma.
The formula – eight egg whites per barrique (225 litres) – has been a Bordeaux-based recipe for fining dry red wines for hundreds of years. An ancillary belief has been that the Bordelais eat an inordinate amount of custard-type dishes after vintage (to use the egg yolks); or perhaps they really did invent béarnaise sauce!
Another rather ancient fining has been isinglass, used for clarifying white wines including Champagne, and beer. It has been derived from the swim bladder of the sturgeon fish (which we mainly associate with caviar), though now it is sourced from other fish too. Similar to isinglass, gelatine is more generally used now, while for students who shuddered at the thought of isinglass, teachers used to pointedly tell us that gelatine was a waste product of animal hooves! Carageen from seaweed is also used.
For those concerned with possible fish residue in their wine, indeed, there may be infinitesimal amounts, but no measurable amount because winemakers filter wine after fining and before bottling. Further, its use is stated on labels nowadays, as is the use of dried albumen (egg white).
Of course, both isinglass and gelatine are purified in manufacture; they act in the same way by combining with some natural proteins in wines to form mucilaginous matter that slowly sinks to the bottom of the tank or barrel (or bottle in the case of Champagne).
Another fining in vogue now is bentonite, a refined clay sourced mainly from Wyoming. Unlike isinglass and gelatine that initiate a chemical reaction with natural proteins, bentonite’s action is rather mechanical.
In my apprencticeship days, I remember a tank of red wine that just would not clarify when fined, and then it took nine days to filter the 30,000 litres to obtain clarity.
With the advent of sophisticated centrifuges and filters, fining is no longer the critical process it was for past generations of winemakers. Hermetic centrifuges, as the name implies, spin particles from wine by centrifugal force, but modern machines do not oxidise the wine in the process.
Filtering is moving towards cross-flow filtering, that is really the way nature clarifies our blood internally, which reminds me that I once saw a tank of wine clarified by the addition of a bucket of blood. It was an old method and the wine was certainly clarified, but I didn’t drink any!
Ian Hickinbotham, one of the most innovative and influential oenologists in Australia over his 50 year career, is the author of Australian Plonky (see related review below).
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