Wine Making: Filtering Your Wines

One way you can raise your wines to a higher level of perfection is by employing the use of filtration. There are many improvements that can be made to a wine through using wine filters. You can enhance its appearance, shorten its aging time, lighten its body and color if so desired, or make the wine more stable, reducing the chance of re-fermentation while in the bottle.

Adding "polish" to a wine's appearance is the number one reason home winemakers elect to filter their wines. Any wine can have its appearance remarkably improved with even the coarsest level of filtration.

Coarse filtration can make a wine that already looks clear, become even more radiant and brilliant than one would suspect. It can take a particular wine one step beyond what is already visually okay. It adds a glassy and pure look to the wine that is simply appealing.

Performing filtrations with finer filters can shorten the time required for the wine to become fully mature. It does so by reducing the excess levels of tannic acid and other proteins. These elements are one of major root causes of harshness in younger wines.

This finer filtration can also lighten the wine's color and body slightly. This type of filtration would be appropriate for all white wines, many roses, blushes and most red wines such a Beaujolais.

There are also filtrations that can be performed on wines that are so fine as to render them almost sterile. This type of wine filtration can take a significant portion of the residual yeast out of the wine, making an accidental re-fermentation much less likely to occur.

Limitations Of Filtration

It is also important to understand that there are some limitations to what filtration can achieve. Filtration will not make a cloudy wine become clear. That is not its purpose.

Filtering devices that are designed for winemaking, perform filtrations that are so fine that they would become clogged very quickly with a wine that was visibly cloudy. Even wines that are just slightly murky can pose quite a challenge for most wine filters.

For stubbornly cloudy wines it is recommended that these wines first be treated with a "fining" or clearing agent instead of filtration. The fining agents will collect and drag particles to the bottom of the vessel, getting the bulk of the cloudiness out of the way before a filtration is performed.

Once the wine has been successfully cleared with a fining agent, only then is it ready for filtration. The fining process should be done about 1 to 2 weeks before the wine is to be filtered.

Types Of Wine Filters

There are two major categories of home wine filters: "Gravity Feed" and "Pressurized" systems.

Gravity Feed Filtration

Just as the name implies, these types of filter systems are performed with gravity as the only pressure. A gravity feed filter system only requires the winemaker to start a siphon from the wine into the filtering unit.

These types of filter systems are very handy when filtering 1 or 2 gallons of wine at a time. They will perform a coarse filtration with the same quality and perfection as bigger more elaborate filtration systems--and they do so for less money.

The negatives are that gravity feed systems are slower than pressurized systems taking an average of 30 to 45 minutes to filter 1 gallon of wine. They are also unable to perform finer filtrations if need be. Only coarse filtrations can be accomplished with these types of systems.

Pressurized Filtering Systems

These types of systems filter a wine by forcing it through wine filter pads under pressure. Some apply pressure through motorized pumps. Others apply pressure manually through hand pumps. Almost all wineries will employ this type of system on their wines.

While pressurized wine filter systems are more expensive than the gravity feed, they are capable of performing much finer filtrations if necessary, and do so at a higher rate of speed.

All pressurized filtering systems perform filtrations equally well. Even the finest filtration is no problem for any of these units. The main difference between them is speed. Simply put, the more money you are willing to spend, the faster your filter system will be.

We offer three different styles of pressurized filtering systems, all the way from 1 gallon per 10 minutes to 1 gallon per minute. They are listed as follows:

Types of Filter Pads:

There are three different grades of filter pads that are available to the home winemaker: Coarse, Polish (medium) and Sterile (fine). They are rated by microns, a very fine unit of measurement based on the metric system.

To help put the micron into better perspective, here are a few comparisons: It takes 25,400 microns to equal 1 inch. That means 1/16 of an inch is still 1,587.5 microns. The dot of an "i" in your local newspaper is still about 200 microns across. And, the finest particle the human eye can see, with 20/20 vision, is about 10 microns.

A "Coarse" filter pad is normally rated at 6 microns. What this means is that for a particle to be able to go through this filter pad it must be 6 microns or less in size. The "Polish" filter is normally rated at 1 micron and the "Sterile" filter is normally rated at 0.5 microns.

Each of these filter pads have a different purpose as well as an appropriate time they should be used. To jump into filtration with the attitude that the finest pad is always the best would be incorrect.

Coarse Wine Filter Pads (6 microns):

This filter pad should be used if you want to add a polish to the wine without loosing any body or color. An example of this would be when you are filtering a heavy red such as Pinot Noir, where a heavy body is key to the wine's character.

Polish/Medium Wine Filter Pads (1 micron):

This is the grade of filter that most winemaker's use. It adds the best polish possible to a wine while taking out only an insignificant amount of color and body.

A pass through this filter pad should also be considered a requirement before attempting to run a wine through any Sterile or Fine filter pad.

Sterile/Fine Wine Filter Pads (0.5 microns):

This pad is capable of removing at least 80% of the left-over yeast that may still be lingering in a wine. It is also helpful in reducing the effects of oxidation that may have overcome a wine.

It is important to remember that a wine should first be passed through a Polish filter before using the Sterile or Fine pads--the issue being the wine may otherwise have more particles to take out than these extremely fine pads can handle.

Be sure to get everything you need to filter your homemade wines in our wine making supplies and wine making equipment!