White wine is produced very differently than red wine, whether made from grapes or juice. Some significant variations include the duration of skin contact, optimum pH, fermentation temperature, maturing period, use of wood, and malolactic fermentation. White wine production appears to be a little easier than red wine production. On paper, there are undoubtedly a lot fewer steps required. However, in practice, this is only sometimes the case. Compared to red wines, white wines are far more delicate. Even the slightest imperfection or error can overpower the flavour and destroy an otherwise excellent wine. Here are the steps I follow to make white wine:
Press and Crush
The first stage in producing a white wine from grapes is crushing and destemming the fruit. With a hand crank-style crusher-de-stemmer, this may be completed quite rapidly at home. Wine may often adjust the spacing between the crushing wheels on crusher-destemmers. To prevent the excessive release of more abrasive seed tannin, change this near enough to burst the berries but not too close that it crushes any seeds.
If you intend to avoid creating red wine in the future, you may save money by purchasing a crusher or crushing the grapes the old-fashioned way. The requirement to remove the stems is slightly less crucial than when creating red wine from grapes since the grapes will be immediately pressed. When pressing grapes, branches can be helpful because they provide lovely, narrow channels through which the juice can flow more smoothly.
It is a good idea to treat the crushed berries with a modest 25–50ppm dosage of SO2 in the form of potassium metabisulfite unless you work with the cleanest, most flawless grapes. This will eliminate any wild yeast, mould, or bacteria, giving wine-friendly yeasts a significant competitive edge because they have a far better tolerance to SO2.
Immediately after crushing, pour into the wine press and start pressing. Some individuals may leave a white wine to be skinned for up to a few hours, but any longer is typically excessive. Next, press directly into transparent carboys using a funnel with a kitchen strainer. The following stages will benefit from being able to see the juice.
During the crushing and pressing processes, keep the grapes and juice as relaxed as is reasonably practicable. As long as there is not too much dew on the grapes, picking in the early morning hours just before sunrise is beneficial.
An important point: It is advisable to avoid this stage entirely and purchase white wine juice unless you are producing white grapes or can pick them locally. The grapes are crushed and pressed directly from the vineyard, which is perfect. However, red wine is an exception. Compared to a red wine that spends several days fermenting with the skins and seeds, flash-extracted red wines that are not fermented with them are frequently bland and lack flavour.
Cold Settling and Racking
After pressing the juice, let it settle for one to three days. To stop any microbial activity at this point, you should keep it cold (45°F). For this, an extra refrigerator is functional. Placing the carboys in big plastic containers and half-filling the containers with ice water is another easy way to keep the juice cold. You will need to add extra ice around twice daily for this procedure.
Rack the settled lees into your fermenter when the juice has settled. Any food- and fermentation-friendly container, such as a barrel, a 3/4-full carboy, a food-grade bucket, a food-grade trash can, and so on, can be used to ferment white wine. When your juice is clean and ready for fermentation, converting it into wine can start.
Start here if you’re producing a white wine from juice:
If necessary, adjust.
It’s time to take a few measures now that your juice has been squeezed and allowed to settle. Check the pH and specific gravity at the very least. You can check the TA at this point, but I will only sometimes make changes based on it.
Most white wines should begin fermenting at a pH between 3.0 and 3.25. You should use a little tartaric acid to correct your pH if it is significantly higher than 3.25. If your pH is below 2.9, you should add either calcium carbonate or potassium bicarbonate to raise it slightly. You may need help starting the fermentation process at these low pH levels. Investing in a reliable pH meter is worthwhile if you want to continue making wine.
Next, use your hydrometer to obtain a reading. Instead of using the specific gravity scale on the hydrometer for wine, we often use the °brix scale. This provides us with a reliable estimate of the percentage of sugar by weight, which gapes will utilize to determine the alcohol content of the final wine. For example, the following equation can be used to estimate the ultimate alcohol content, or ABV, of a wine produced dry: % Alcohol = 0.57 * °Brix. The original reading from before fermentation is used in this case for the °Brix. Although the amount of sugar converted to alcohol during each fermentation differs somewhat (vine will also transform some sugar to water and CO2), this will bring you quite close to creating wine at home.
Depending on the type of wine you plan to brew, your hydrometer value should be between 18 and 24°brix. By adding a little water, you can reduce the sugar level of the grapes if you discover that they are a touch overripe and have more sugar than you want. With white wine, this is considerably less of a huge concern. It would be an extremely unusual occurrence and a tough choice for me to add water to red wine. You can “chaptalize” or add sugar in the form of table sugar or simple syrup if you discover that the grapes do not have enough sugar. To calculate the correct amount of sugar to add, multiply your sugar levels by 1.5 oz of table sugar per gallon to get a 1° brix increase.
Fermentation can now start.
Bring the juice up to around 70°F to begin the fermentation. Avoid doing this too slowly since, in the 50–60°F range, some unfavourable yeasts that produce acetic acid can outcompete wine yeast.
Select a trustworthy yeast that can ferment well at lower temperatures and is not overly nitrogen-hungry. Many people use d47 to make white wine. However, if the circumstances aren’t precisely correct, it can release a lot of hydrogen sulphide (H2S). Renaissance Fresco is the white wine yeast I use the most. Although this yeast is officially designated as a cider yeast, it performs admirably when producing crisp white wine.
Make a yeast starter to ensure a robust and dependable start to the fermentation. Using Go-Ferm will assist your colony in becoming more potent before being added to the wine. Add a little of your juice to the starter after the hydrated yeast starts to show indications of activity. Pour carefully onto the juice’s surface after your good, vigorous starter is within 10°F of the liquid. There’s no need to mix it in.
Keep an eye out for fermenting hints. After 12 to 24 hours, you should notice a few little bubbles. Once the juice has begun to ferment quickly, reduce the temperature to assist retain the juice’s volatile and delicate fruity fragrances. This is essential for producing a crisp, bright white wine. Renaissance Fresco, a non-H2S yeast, allows for very low maintenance fermentation at temperatures as low as 55°F. Several times each day, put frozen 1L, 2L, or 1-gallon bottles into the fermentation or use the chilly water in the binning technique indicated above to lower the temperature.
After a day or two, feed the yeast with quality yeast nutrition like Fermaid K. If you feed before your selected yeast actively ferment, you risk encouraging an undesirable yeast or bacterium to escape. Most other bacteria cannot compete after a good wine yeast has begun to ferment.
Stir and watch
Twice a day throughout the fermentation, stir the wine. When stirring at the beginning, add a little air. This will make it easier for the yeast to grow and use aerobic respiration to regain energy.
Every time you swirl the wine, take a whiff. Keep an eye out for any H2S that smells like rotten eggs or sulphur. This is a sign of a stressed fermentation that is nitrogen- or air-starved or occurring outside the optimal temperature range to bring the fermentation back to a happy medium, feed and aerate it. The smallest amount of H2S smell today can cause mercaptan to become detectable later, giving the wine an unpleasant flavour of burned rubber or garlic. To eliminate the sulphur smell, you can use this product to treat if a bit of nutrition and air is insufficient.
Acetic acid, found in vinegar, and acetaldehyde in port wine or sherry are signs of underfed yeast or excessive oxygen exposure, respectively. Even while it happens less frequently when fermentation is active, it is something to be aware of, particularly when it slows down. The yeast is capable of converting these substances back to ethanol if discovered in time. In this situation, fermentation may be completed with a small amount of yeast nutrition and less air contact. If you notice any oxidative odours once fermentation is finished, it will be crucial to use sulphite.
Once fermentation is finished, do not add yeast nutrients if you detect the aromas of vinegar, acetaldehyde, or ethyl acetate (nail polish remover). A kind of acetic acid bacteria is the most likely culprit in this situation (AAB). At this point, any additional nutrients will feed the harmful bacteria. Instead, the recommended course of action is to reduce air exposure, use a sterile filter (if possible), and try to tie up at least some of the acetaldehyde using sulphite.
Consolidate and Wait
Usually, when fermentation is finished, you’ll add enough SO2 to stop malolactic fermentation. The wine will undergo malolactic fermentation, changing its flavour so that it becomes more buttery and savoury. I like to add a significant amount of SO2—75 ppm or more—all at once when the fermentation process is finished rather than continually regulating the SO2 to maintain protection.
The malolactic fermentation process benefits some white wines, such as Chardonnay. Forget what I just mentioned in this situation, and instead add a solid, dependable malolactic culture like CH35. In this instance, you will find sulphite when the malolactic fermentation is finished.
Should White Wine Be Oaked? Not typically. The delicate fruit notes of white wine can be swiftly masked by a bit of oak. Occasionally, you’ll come across a chardonnay that has been matured on wood or an oak-aged Riesling that is meant to be aged for a long time. Is my white wine oaked? … no. I haven’t produced any white wines that I believed might benefit from oak, at least not yet.
It is worthwhile to cold stabilize the wine before bottling now that it is microbially stable. Refrigerate the wine for a time to have a cold, regular wine. This can be completed in a week at 30°F or a few months at 40°–50°F, such as in your garage during the winter. A portion of the wine’s tartaric acid will react with potassium and precipitate out as potassium bitartrate (cream of tartar). To avoid finding any unattractive crystals in the bottles, cold stabilization encourages these tartrate crystals to fall out before the wine is put into a bottle.
All that’s left to do is wait for the wine to become crystal clear, which typically takes three to six months. When the wine is clear, you can either bottle it or back-sweeten it. Most white wines are ready to drink after six to twelve months. Remember that the wine will likely be served cold when sweetness is added. This makes chilled serving temperature the ideal temperature to taste different test degrees of sweetness rather than storage temperature.
Bottle and Degas
Degassing to get rid of the majority of the wine’s dissolved CO2 is usually worthwhile since white wines may be bottled at a young age. With the use of a degassing tool, such as this drill mount degassing tool, the wine may be bottled rather rapidly. You don’t need to go too fancy with white wine because the serving temperature is cool. Since CO2 is more soluble at lower temperatures, it is doubtful that you will see any bubbles while pouring wine unless it is exceptionally CO2-saturated. Instead, they will likely remain dissolved. In the case of red wine, however, this is not the case. If a wine is bottled with a small quantity of dissolved CO2 and then warmed to 65–70°F before serving, you will frequently see a few tiny bubbles around the rim of the glass and maybe taste and feel the CO2 itself.
a Cold Crash (Optional)
You can purposefully delay your fermentation and leave some excess sugar rather than back-sweetening. Even while it’s not very simple to perform, doing it correctly can result in a fruitier and more fragrant wine. Before the fermentation is finished, you should cool the wine to around 30-35°F to prevent cold crashing. A small amount of unfermented sugar will remain after this stops the fermentation. I removed the lowest shelves from a spare refrigerator to fit two carboys. This is effective for both cold crashing and stabilizing. Leave the wine refrigerated until it is crystal clear, which might take a few months, to hard crash efficiently. Once clear, rack off the lees and add potassium sorbate to stop re-fermentation and potassium metabisulfite to avoid malolactic fermentation or spoiling. You may now warm the wine back up to the standard cellar temperature.
The majority of juice-fermented wines will proceed in a manner akin to white wine. Apple wine and other fruit wines not fermented with whole fruits or skins fall under this category. Consider frozen juice pails or a premium white wine kit if you can’t get fresh juice in your region or want to ferment during the off-season.