Sediment has long been an inconvenient reality for the home winemaker – one that if not dealt with properly can lead to sediment at the bottom of your wine bottles. It’s enough to make a grown man cry. But if one takes the proper precautions they can guarantee that such a flaw does not happen to their precious wines. Here’s how to stop sediment in wine bottles.
Sediment is something that occurs during the fermentation, and it is something that can still accumulate even after the fermentation has completed. Most of the sediment is yeast cells that have given their life to the cause. A smaller percentage is fiber and other proteins from the fruit, whether the wine be made from grapes or grapefruit.
The savvy winemaker knows that the wine needs to be transferred off the sediment once the fermentation begins to slow down. Transferring the wine is a process called racking. The first racking is to get the majority of the sediment out of the way, but the winemaker also knows that more sediment will be on the way, and that additional rackings will be necessary. With each progressive racking the wine will slowly becomes clearer and clearer.
This is all well and good, but the big question here is, how does the winemaker know when the sediment formation is done? When will it be okay to bottle? Do they just wait until the wine looks clear enough?
For most, it is a simple matter of watching and observing. If the wine is racked off the sediment into a clean secondary fermenter, such as a carboy, and no new sediment is created at the bottom, then one can reasonably deduce that all the sediment that is going to occur has done so. The wine looks clear; no more sediment; time to bottle the wine!
Most of the time this approach will result in a spectacular wine – one that is brilliantly clear and one with no sediment at the bottom in the wine bottles. But from time to time there will be that particular batch that mysteriously comes up with even more sediment after the wine has been bottled.
The wine looks perfect, beautiful, worthy of being shared with family and friends. Then a month or two later you go to the wine rack to pull another bottle only to find that sediment has somehow formed.
What caused this? Can I get rid of it? Is my wine ruined? How do I stop sediment from occurring in my wine bottles? These are all valid questions and questions I will answer here:
Is My Wine Ruined?
First, your wine is not ruined. Having sediment at the bottom of your wine bottles is the result of something falling out of the wine. It has nothing to do with a spoilage. If it were a contamination issue you would typically see a growth at the top, near the air-pocket in the wine bottle. Molds, bacteria and other little nasties need oxygen to grow and tend to form near it.
What Caused The Sediment?
There are three main reasons for having sediment at the bottom of your wine bottles:
You bottled the wine too soon
This is by far the most common reason for sediment in wine bottles. It is possible for a homemade wine to look reasonably clear and still have some sediment to give. The last stuff to fall out from the fermentation is the finest of particles – as fine as flour. The heavier particles fall out sooner. Each one of these individual particle cannot be seen with the naked eye, but in numbers they can add a murkiness to the wine. Sometimes the murkiness is so slight as to go unnoticed. The best way to make sure that all the particles from the fermentation have settled is to use a wine clarifier or fining agent. A wine clarifier will collect and drag out the particles in a quicker, more efficient manner. Another thing you can do is be more patient. When you rack the wine into a fresh carboy, give it plenty of time to show the presence of sediment: two weeks, even a month. Sometimes more time is all that is needed.
Potassium bitartrate crystals are forming
Potassium bitartrate is essentially tartaric acid that is crystallizing and then falling out of the wine. This most commonly occurs with grape wines that are made from actual fresh grapes. And, it is more common in white wines than reds. Grapes are high in tartaric acid. It’s the most abundant acid found in a grape. Sometimes there is more tartaric acid in the wine than the wine can hold in solution. The result is the formation of bitartrate crystals, sometimes referred to as wine diamonds. These are very tiny crystals that resembles salt. They form out of thin air, so to speak. It is important to note that the cooler the wine is the less tartaric acid the wine can hold. So It is possible for a brilliantly clear wine to form these crystals months later as cooler weather comes about. To combat this from happening, many wineries will chill the newly made wine so as to cause the crystals to form before bottling, making the wine cold stable. As a home winemaker, if you are making wine from grapes it would not be a bad idea to chill the wine down for a week or two before bottling to allow the opportunity for any potassium bitartrate crystals to form that can. To help entice the process even further you can add Cream of Tartar to the wine. This is the stuff you can buy at the spice rack at the store. Only a tiny amount is need: 1/4 teaspoon to 5 gallons is plenty. This will potentially set off a chain reaction of crystal formation.
Protein is dropping out of the wine
Much like excessive tartaric acid can drop out of a wine as tiny crystals, excessive protein can drop out of a wine as a dust or powdery-looking substance. Most of the protein is in the form on tannins. These tannins can start to form deposits months after the wine has been cleared and bottled. It is when a bottle of wine becomes slightly warmer that you can sometimes see them start to form and settle. You can sometimes observe this even in commercially made wine. It shows up as a dark, dusty sediment deposit at the bottom of the wine bottle. This is the least common reason for having sediment at the bottom of your wine bottles. Most homemade wines will not have excessive protein, but it does happen. It is most common in red wines, whether it be from grape or fruit. It is often the result of the fruit being over processed or left in the fermentation too long. It can also be from storing the wine at too warm of a temperature. One way to help prevent this instability from arising is to treat the wine with bentonite. This is a clarifier that is very effective in removing significant amounts of protein from a wine. It is routinely used by wineries after the fermentation to drop out the yeast more quickly.
Can I Get Rid Of The Sediment?
There is no magical way to get rid of any sediment you may find a the the bottom of your wine bottles.
It is possible to re-bottle a wine. You can decant the bottles of wine back into a common vessel; allow the wine a few days to clear; and then re-bottle. But, this treatment has a downside by way of excessive air exposure. The wine can become oxidized if one is not extremely careful. It will be important to treat the wine with potassium metabisulfite upon decanting and again before re-bottling. This will help to drive out oxygen that has saturated into the wine during decanting. It will also help to keep the wine fresh and free of spoilage.
In reality, the best path for this type of wine fault is one of prevention. Do things things that will help stop sediment from occurring in the wine bottles: give the wine plenty of time to clear; use bentonite routinely; if you can, chill your grape wines; don’t over macerate your fruit; and don’t leave it in the fermentation too long – 3 to 6 days is plenty. If you do these simple things, having sediment in your wine bottles should never be an issue.
If you do discover that you do have sediment at the bottom of your wine bottles, you will be happy to know that it does not affect the wine’s flavor or character in any negative way. In fact, the wine will usually improve after such an occurrence. It is primarily an issue of esthetics. Who wants to share a wine with sediment at the bottom?
That being said, if you keep the wine to yourself, no harm, no foul. Carefully pour the wine into your glass. When you get to the bottom of the bottle, dump the little last down the drain. Problem solved!
Ed Kraus is a 3rd generation home brewer/winemaker and has been an owner of E. C. Kraus since 1999. He has been helping individuals make better wine and beer for over 25 years.