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Thread: Chaptalisation

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    Oct 2005
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    Default Chaptalisation

    Courtesy of Pat Cuthbert (many thanks for the use Pat)

    Chaptalization 101

    What is Chaptalization ?

    Chaptalization is the process of adding “sugar” to a fermentation to increase the level of alcohol in the finished product.

    There are several reasons why Chaptalization is done.
    1: The fruit may not have enough natural sugar.
    2: The wine maker may wish to increase the alcohol potential of the fermentation.
    3: The wine maker may wish to halt a fermentation leaving residual sugars.

    Let us look at each of these situations in turn.

    1: Fruit may be picked “early” because of environmental concerns. Weather or insects are the most common of these concerns.
    If the weather changes abruptly, the fruit may not finish ripening properly. An early frost can halt the ripening process leaving the fruit with less than ideal sugars. The acids found in the fruit that has not ripened may also need adjustment to create your ideal wine. Fruit wines are generally fermented to be less than 9% ABV, but many fruits will only have enough natural sugars to ferment to the 5 to 7% range. In this case, sugar is added at the beginning of the fermentation to bring the specific gravity or brix of the must to the desired level.

    2: Sometimes, the wine maker wishes to create a product that has an ABV that is significantly higher than commonly found. This may be in preparation for distillation or to produce a high ABV beverage.
    For the home winemaker, the intention is generally to increase the alcohol level. An increase in the alcohol level can contribute to a longer “shelf life” for their wine, but can reduce the drinkability of the wine early on, leaving a “rocket fuel” taste. More frequently, though, home wine makers use Chaptalization to create a “port style” wine. These are typified by higher alcohol and residual sweetness. Preparation for this process is quite detailed, and requires careful measurement of the many factors that go into making a good wine. Planning and record keeping are of the utmost importance. A good calculator such as “WineCalc” will aid in the planning stages. A spreadsheet based record, such as the one found here: http://www.winepress.us/forums/index..._1#entry310480 , will help to keep track of this process. Selection of the proper yeast is also important. Depending on the final alcohol level desired, there are a number of great yeasts available. Most commonly used is champagne type yeast such as Lalvin EC1118 or red Star Premier Cuvee. These yeasts will easily ferment to 18% ABV and may be coaxed higher under ideal conditions. They are neutral and influence the wine minimally. To begin a fermentation where Chaptalization is intended, one needs to adjust the acid levels a bit higher. This is especially true where the wine is intended to be sweeter as the sugars and acids should be balanced. Most acid adjustments should be done prior to the beginning of fermentation. I suggest the use of Malic acid for this adjustment. MaloLactic fermentation is not frequently used for “port style” wines, and tartaric acid will tend to dissipate over time. You will have determined the desired ABV of the finished wine before you start so you will know what the total needed sugar is to reach that level. This is important so that you can plan your sugar additions to bring the wine to that level. I like to start a fermentation intended for Chaptalization at about 23 brix (SG 1.095 to 1.100). This will give the fermentation a good start and allow a strong yeast colony to build. Once fermentation has commenced, keep track with the same hydrometer you used at the start. This will maintain the calibration to assist in record keeping. For the purposes of this demonstration, we will use an intended finished alcohol by volume of 18%. We will use a volume of 23 liters (approximately 6 USG). We will use the initial starting gravity of 1.100 which will yield a wine with 13.5% ABV. So, we see that we will have to increase the ABV by 4.5% to reach the target. By entering the information we have, Opening gravity 1.100, Volume 23 liters, and our target alcohol 18% into WineCalc, we see that we will have to add 2050 grams of sugar during the fermentation. This number is actually a bit low as we will be dissolving the sugar in water before the addition, increasing the total volume slightly. 2050 grams of sugar will completely dissolve in 1 liter of water, so the total volume will be 24 liters. It becomes a bit tricky here finding the true amount of sugar to add, but you will be safe planning for another 250 grams of sugar, bringing the total to 2300 grams (5.2 pounds). We have now calculated the sugar required to give us 18% ABV. We know our starting gravity of 1.100. We have selected our yeast. We have adjusted our acid. We are ready to begin the fermentation! Rehydrate the yeast or sprinkle the yeast on top of the must as is your practice, and allow the fermentation to begin. Monitor the SG, and allow the must to drop to 1.010. This gives the yeast a chance to condition to the higher alcohol level in the must while still being strong enough to accept the new sugars available. Once the must reaches 1.010, mix of the sugar into water until dissolved. 2 parts sugar to one part water will dissolve completely resulting in a clear syrup which will be added to the must. This will bring the SG of the must to about 1.030. Allow the fermentation to continue again until the SG reaches 1.010. Prepare and add the remaining sugar syrup as described above. Again, the SG will be about 1.030. Allow the fermentation to proceed to dry. You will now have a wine with an ABV of 18% and an SG of about 0.995 . Further fermentation is possible at this point with the addition of more sugar, but it must be done extremely slowly, so we will look at reason 3 above.

    3: The wine maker wishes to halt the fermentation leaving residual sweetness.
    We now have a wine that has an SG of 0.995 and is dry. We wish to turn this into a sweeter wine to match the acid adjusted at the beginning of the fermentation. We can do this with bench trials to find the “right” sugar level, or we can use an assumption of the final gravity. The choice is yours, depending on the amount of time and effort you wish to put into the process. From past experience, I find that a finishing gravity of 1.010 is just about perfect for me. This is a level where I can taste the fruit forwardness of the sweetened wine. Bench trials are difficult at this point because the increased alcohol can be difficult to taste through. (HINT: take a SG on a port style wine that you like and go with that) Going to WineCalc, we have a small problem. The program will not accept an input below 1.000. To overcome this, increase the SG of the wine you have by 0.010, and the desired finishing gravity by 0.010. In this case, we increase the finished gravity of the wine from 0.995 to 1.005, and the target gravity from 1.010 to 1.020. This gives us an increase of 650 grams of sugar to bring the wine to the desired sweetness. Since the yeast are now stressed from the high level of alcohol, this sugar addition will generally cause the yeast to go dormant. An addition of potassium sorbate will ensure that the yeast will not become active again. You may also desire a higher level of alcohol in this wine. I prefer to use an alcohol addition for this increase. Again, the use of WineCalc will help in the calculation of the amount of alcohol to add to reach the desired end result.
    Last edited by lockwood1956; 06-10-2011 at 06:10 PM.
    N.G.W.B.J.
    Member of 5 Towns Wine and Beer Makers Society (Yorkshire's newest)
    Wine, mead and beer maker

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