Wine is an alcoholic beverage that is mainly produced from fermented grapes. Usually, yeast consumes the sugar in the grapes and converts it to ethanol, carbon dioxide, and heat. For wines not made from grapes, they undergo a fermentation of additional crops, including rice wine and other fruit wines like plum, cherry, pomegranate, currant, and elderberry.
Unlike the fermentation that happens in alcohol that doesn’t require stirring, during winemaking, you must stir your wine during the primary fermentation because the yeast in your wine needs a significant supply of oxygen during this ‘aerobic’ fermentation, meaning with air. It also keeps your grapefruit in solution if you ferment fruit, grapes, or any fruit. If you don’t, you will see a solid cap forming on the surface of your container. Yeast requires more oxygen during primary fermentation. It also helps to get rid of trapped carbon dioxide from the must. And this will help fermentation reaction to run faster.
You need to stir your wine thoroughly at least once a day if you want to enjoy a clear wine. You might need to stir it more than once a day, or maybe twice, primarily if a heavy cap is formed at the top of the must. When your wine is still undergoing primary fermentation, please place a cheesecloth or tea towel to cover the top so that bugs will not find their way in. Bugs naturally love the smell of fermentation.
But stirring your wine depends on the type of wine, especially white wine. White wine is usually fermented from only the juice after pressing, so as the fermentation rate drops, particles will begin to sink, and you are not supposed to stir it up. If you do, you might need to carry out extra filtration and fining to clear the wine.
But red wine is different because they are fermented with the skins on, and there is a need to stir your grapefruit at intervals to get the benefits of color and tannins; there is, in fact, a patented type of fermenter that does this automatically by trapping some of the carbon dioxides under the fruit and releasing it in a bubble to agitate it at a rate controlled by a valve, to the extent when the operator can stop the agitation completely.
Wine has existed for many years, and it is produced by different people from different cultures and countries, each with its distinct style and taste.
Wine is made by first selecting the grapes. It is not easy to do this because the taste of a grape changes based on when it is picked, with the acidity, sweetness, and flavor all being affected. Depending on the size of the vineyards, the grapes can be selected either by hand or by machine. Also, if picking of grapes falls during hotter days, night picking may be done instead to increase the efficiency. Then you go ahead to crush the grapes. Most winemakers use the de-stemmer machine because it removes the stems and bits you don’t want while crushing the grapes into liquid mush. For white wine, the skins and seeds are removed to get rid of any color that will affect the liquid, but the skin of the grapes is not removed for red wines.
When you are done crushing your grapes, the next thing for you to do is ferment them. Here, the sugar in the mixture gets converted into alcohol. This is when you will add yeast and allow it to ferment over time. For red wines, carbon dioxide is released and usually fermented in warmer temperatures, unlike white wines. The red wine process usually continues until all the sugar is converted into alcohol, thus producing a dry wine. White wines can also be fermented until dry, but the sweet wine varieties stop before all the sugar is converted, thereby providing a sweeter and less alcoholic drop.
When fermentation is complete, you age your wine. And aging varies depending on time, place, and process. Wines can be aged for some months or even years.
After aging your wine, you bottle it. But before you do that, your wine must go through a filtration process that eliminates the unwanted particles left in the liquid. After this is over, the wine is ready to be bottled. After the wine bottle is slowly filled to the top, the winemakers will pop in a bit of nitrogen or carbon dioxide to remove any oxygen that might be lingering on top of the fill line. It is corked and ready to be consumed or sold.
Turning grape juice into wine means to vinify. A wine press is used to extract the juice from grapes when they are pressed. The freshly squeezed grape juice that contains the skins, seeds, and stems of the fruit is called must; everything apart from the juice (skins, seeds, etc.) is called pomace or marc.
What are primary and secondary fermentation?
Primary fermentation is the initial fermentation, where yeast converts sugars in grape juice or must to alcohol (wine) and carbon dioxide. Secondary fermentation is either a continuation of the primary fermentation of sugar to alcohol that occurs after the wine is moved from one kind of container to another, like from stainless steel to oak, or a supplemental fermentation triggered after the primary fermentation is complete by the addition of sugars.
The moment you add your yeast to your must, that is when primary fermentation begins. At this stage, the population of yeast keeps growing significantly. So, you will see a lot of visible activity and plenty of foam on top of the must; your airlock will also be bubbling very well. It is the most active and productive phase of fermentation. This is when up to 70% of the total amount of alcohol is produced, and it only lasts for about three to five days. But during secondary fermentation, after a while, the activities in your must starts to slow down. The oxygen has been depleted, and the bulk of the sugar has been used up. As a result of this, the yeast population is no longer expanding.
Secondary fermentation lasts between a week to two weeks. So, it is a much slower stage in the process. While primary fermentation takes about three to five days to produce 70% of alcohol, secondary fermentation takes up to two weeks to get the remaining 30%. You will notice that the foam will disappear, and you will see tiny bubbles breaking at the surface of your wine. Your airlock will now be bubbling every 30 seconds or so.
There is no specific event that separates the primary stage from the secondary stage. The period it occurs depends mainly on the sugar content, grape varietal, yeast strain, fermentation temperature, and others. All you need to do is to watch your airlock or the level of activity at the surface.
Secondary fermentation is not the same thing as second fermentation. The second fermentation is where excess sugar not previously consumed by the yeast restarts alcoholic fermentation. It happens when a wine is back sweetened before all the yeast has died. Usually, a second fermentation occurs by accident except when making sparkling wines. Sparkling wines are bottled before the yeast is dead, and a little unfermented grape must is added to give the yeast something to eat. That way, the carbon dioxide produced is trapped in the bottle, and it bubbles.
Should you shake wine while it’s fermenting?
During primary fermentation, it is okay for you to shake wine, but during secondary fermentation, when the dead yeast and trub have settled out, you should avoid shaking your wine because if you do, it will give it some off-flavors.
Should I use an airlock during primary fermentation?
You need air during primary fermentation so that your wine yeast can quickly multiply to its fullest potentials. If you try to use a wine airlock during primary fermentation, it will prevent air from entering, suffocating the wine yeast and preventing its reproductive ability.
You can either cover the container where your wine is with a thin towel or cheesecloth or something similar instead of using a wine airlock. You can also protect it by tying it down with a string to ensure it doesn’t get knocked or blown off. If you do this, you will allow the wine yeast to get all the air it requires without allowing bugs and other little nasties to enter the mix.
After about 4 to 6 days of fermentation, the wine yeast will go into its slower, secondary fermentation. This is the right time for you to make use of a wine airlock. By this time, the air is no longer needed, and in fact, is a challenge to the must at this point.
There are certain things you should know about wine fermentation. Some of them are:
- You should practice cleaning and sanitizing your equipment. Clean your equipment before and after your homebrew. If you don’t keep your equipment clean and sanitized, you will provide a breeding ground for unwanted bacterias that can contaminate your wine. Yeast works perfectly when it is alone, and letting in any undesirable bacteria or chemical can give you a wine that has a horrible taste.
- Use the correct temperature for making your wine. If you use the wrong temperature, it can render your yeast inactive and hinder the fermentation process. A suitable recommendation for fermenting wine in temperature is to keep the temperature between 70 degrees Fahrenheit to 75 degrees Fahrenheit.
- Have an idea of how your yeast works. During the winemaking process, you can either decide to add yeast or use the natural yeast found in the fruits or berries you use. If you store your yeast correctly, it can give it a more extended expiration date. It is good you keep your wine yeast in the fridge.
- Use a hydrometer to monitor the process of your fermentation. With a hydrometer, you can track the alcohol content of your wine, thus giving you a rough estimation of how long the process is. If you don’t use a hydrometer, you can’t be very sure the fermentation process has been completed.
How do you know when primary fermentation is done in wine?
During the primary fermentation stage, you will notice a lot of visible activity. You will often see a lot of foam on top of the must, and your airlock will be bubbling very well. So, when you notice a reduction in the visible activities, that is when you will know that primary fermentation is over.
What happens if you drink wine before it’s done fermenting?
If you drink wine before it is done fermenting, the taste would be awful. Although it is not harmful, it won’t taste good.
Can you let wine ferment too long?
You cannot allow the wine to ferment for too long because wine does not ferment for too long. Even if you cannot get the right balance between sugar and yeast, you can still salvage it by carrying out some procedures on your wine. You should know that the fermentation process of wine and any other alcohol naturally stops in most cases. For instance, when making dry wine, you are supposed to leave the fermentation long after it is over, this doesn’t affect the wine batch, but it gives it a unique taste found in dry wines. But you can spoil your wine by exposing it to unwanted bacteria or other things for too long.
Usually, the fermentation of wine generally takes a minimum of two weeks and then two to three weeks of aging before it is ready for bottling.
You need about two months to make wine at home. But some winemakers advise that you don’t drink your wine immediately after two months because the longer you let your wine age, the better the taste.
What should wine taste like after primary fermentation?
After primary fermentation, if there is still sugar to be fermented (sg 1.010 or higher), then your wine should taste at least a little sweet. But if it has fermented down below 1.000, then it won’t taste sweet at all. At this stage, there will be a lot of carbon dioxide in the wine. So, it may have a sour taste. Your wine will mostly have an unpleasant taste after primary fermentation because it takes time for the alcohol to mellow and balances out in flavor. So, after primary fermentation, you need to keep an airlock on your wine and let it age before bottling it in a few months.
Conclusion
It is very pertinent for you to stir your wine during fermentation to enjoy a clear wine without sediments in it. You are also free to shake your wine while it is still fermenting. It is also not harmful to consume wine that has not been entirely fermented, but the wine will not have the pleasant taste it should have if it is completely fermented.