By: Mackenzie Brisbois, Edited: Alex Sproll
Look through a glass of wine, and what do you see? Is it clear and transparent or is there perhaps a slight haze or cloudiness? It used to be that cloudy wine was called “unfinished”. Thankfully the wine world has moved on from that point of view. Similar to beer, teas or other beverages wine can be cloudy and be better for it!
Conventionally, most wines are clarified by A) Fining and B) Filtering. This is if one follows textbook winemaking techniques that would have been championed a generation ago. But that fact is, except for sweet wines, filtering (or fining) is just not necessary.
Filtration is only one part of the clarification of wine. To change wine from murky to clear there are many actions to remove suspended materials. These include things like protein stabilization and tartrate stabilization. There are some common practices utilized by wineries when putting a wine to bottle.
A wine will clarify if let to stand for a long time, but even if a wine looks clear it can still contain many particles that you might not be able to see, which can come out of suspension in bottle. Wines can be filtered in different ways, using a pad filter (often called plate and frame), a membrane filter, mechanical separators or cross-flow.
What is the Real Deal with Filtering Wine?
There is not one straight answer. There is general consensus that if you filter a wine too much you strip out a lot of flavour and aroma and texture. Wines that have residual sugar or have not completed malolactic fermentation a choice to not filter will result in an unstable product and this can result in real losses (as in bottles can explode).
There is not one straight answer. There is general consensus that if you filter a wine too much you strip out a lot of flavour and aroma and texture. Wines that have residual sugar or have not completed malolactic fermentation a choice to not filter will result in an unstable product and this can result in real losses (as in bottles can explode).
The biggest concerns in wine stability are yeast and bacteria. If a wine has residual sugar all the yeast need to be removed through filtration so that it doesn’t referment in bottle. If a wine has not gone through malolactic fermentation then all the bacteria need to be removed through filtration in order to prevent this process happening in bottle. The simple answer to this is that we do not make these types of wines anymore. All our wines still wines are dry and most natuarally go through malo, or they are sparkling and bottled in glass to match.
Of course nothing ever goes to plan, or it would be easy! Some wines just never seem to go through malo — or at least not in a timeframe where their flavours would not oxidize. Our 2018 skin ferments were such wines. These wines were fermented on their skins for fermentation, were pressed and were put to barrel. They were fermented naturally until dryness so they are considered dry,meaning there are no more sugars to ferment. Because there is no sugar for yeast to act on it is not necessary to remove the yeast, no need to filter out yeast.
The wines were then put to barrel to settle and they are left untouched until the spring. This gives the wines time to settle naturally – with sediment falling to the bottom. More time would mean more settling and more clarity. Still there is a chance of malolactic fermentation taking place. Sulphur was added to inhibit this process. It’s not fool-proof, but it reduces the chance of refermentation.
The other technique we employ is observation and patience. We simply wait for the wines to settle out and then rack them, removing the clear wine from the thicker lees (dead yeast and sediment) that have fallen to the bottom of the barrel over time).
And then we taste them and bottle them.
More Cool Stuff for Wine Nerds
Suspended particles in wine can be proteins, pectins, metalcolloids (iron and copper), polyphenolic polymers, tartrates. Suspended particles can be electrically charged and they can be small enough that they won’t fall out of suspension by gravity and will make the wine look cloudy. That’s where intervention comes in.
Suspended particles in wine can be proteins, pectins, metalcolloids (iron and copper), polyphenolic polymers, tartrates. Suspended particles can be electrically charged and they can be small enough that they won’t fall out of suspension by gravity and will make the wine look cloudy. That’s where intervention comes in.
Proteins in wine need to be stabilized using an opposite electrical charge, like bentonite. The bentonite is mixed into the wine, the negative charge pairs up with the positively charged protein and it falls to the bottom. The wine is racked off the bentonite.
Tartrate Stabilization is commonly done by chilling a wine to remove potassium bitartrate and calcium tartrate which forms crystals in cool conditions.
Some Things That Could be Used in Stabilization:
Activated Carbon – reduce colour and remove bad odours
Gelatin – used to reduce tannin
Egg Whites – soften red wine astringency
PVPP (poly-vinyl-poly-pyrrolidone) – used in white wine to reduce tannin, reduce oxidation
Don’t worry.
We don’t use ANY of these products!
Activated Carbon – reduce colour and remove bad odours
Gelatin – used to reduce tannin
Egg Whites – soften red wine astringency
PVPP (poly-vinyl-poly-pyrrolidone) – used in white wine to reduce tannin, reduce oxidation
Don’t worry.
We don’t use ANY of these products!