Keep in mind you will need to add some form of sugar prior to the second fermentation process in order to fuel the yeast; if you would like to flavor your kombucha with veggies or keep the flavor profile basic, you can achieve carbonation by simply adding approx. 2/3 tsp. of sugar.
-Increase sugar in your secondary fermentation. You can do this by adding fruit, fruit juice or sugar. I'll add ¼-1 tsp sugar per 16 oz bottle if my flavoring doesn't have any natural sugars in it. -Fill your secondary fermentation bottles closer to the top leaving an inch of space between the kombucha and the top.
Sugar can be added to encourage the secondary fermentation, as well as in the "dosage" of bottle-fermented sparkling wines, when a mixture of sugar and wine is added to the bottle after the yeast sediment is removed.
Add sugars – If you find that your alcohol content is a little lower than you'd like, you can add additional sugars when putting your beer into secondary fermentation. It can be corn sugar, brown sugar, honey, or dried malt extract… any fermentable ingredient can be used to boost gravity.
Pure sucrose is the reference standard for all fermentable sugars because it contributes 100% of its weight as fermentable extract.
A little sugar (or syrup) makes the yeast ferment faster and more effectively than when no sugar is added. The carbon dioxide makes the dough raise and the bread porous.
Another reason both glucose and sucrose seem to be favored by yeast in fermentation could be related to oxygen. Yeast can use oxygen to release the energy from sugar in a process called “respiration.” Thus, the more sugar there is, the more active the yeast will be and the faster its growth.
Preparation for secondary fermentation in bottle:
7) Sugar addition ('liqueur de tirage'): Addition of beet sugar at 23 to 26 grams/litre, depending on the alcohol content and pressure required; the higher the alcohol and the greater the pressure required, the more sugar needs to be added.
Sometimes very ripe grapes result in wine that still has residual sugar when the alcohol level goes above what the yeast can survive. Port wine has alcohol added when the wine still has unfermented sugar. Adding more sugar in these cases won't restart fermentation.
Too much sugar can also lead to over-carbonation. In addition to alcohol, carbon dioxide is a byproduct of fermentation. This is why priming sugar can be used to carbonate beer. If there are residual sugars for the yeast to ferment, higher CO2 levels can be a result, which will be noticeable in the body of your beer.
While sugar and other sweeteners provide "food" for yeast, too much sugar can damage yeast, drawing liquid from the yeast and hampering its growth. Too much sugar also slows down gluten development. Add extra yeast to the recipe or find a similar recipe with less sugar. Sweet yeast doughs will take longer to rise.
Sugar Levels Determine Fermentation Dynamics during Yeast Pastry Making and Its Impact on Dough and Product Characteristics.
The best way to increase the ABV is to add more fermentable sugar for your yeast to snack on. Unfortunately, dumping a few extra cups of sugar into your wort, and praying for success won't get you the beer you want.
During the secondary fermentation stage, most of the sugars have been consumed and the alcohol by volume (ABV) increases. With the majority of the sugar consumed, the rate of fermentation decreases while the alcohol content continues to increase.
It is a good idea to check your gravity throughout fermentation, as it will continue to drop until it is completed. Once you notice that gravity has stopped dropping, you know secondary fermentation is complete and you can move to bottling.
A higher concentration of glucose will increase ethanol production because sugar molecules will be more readily available for the cell to use for fermentation.
Wines can be enhanced with added sugar.
Chaptalization is a process common for centuries, in which sugar or grape concentrate was added to fermenting grape must to boost the alcohol level in the finished wine. This used to be most prevalent in northern climes where it was difficult to ripen grapes consistently.
Alcoholic fermentation, also referred to as ethanol fermentation, is a biological process by which sugar is converted into alcohol and carbon dioxide. Yeasts are responsible for this process, and oxygen is not necessary, which means that alcoholic fermentation is an anaerobic process.
There is absolutely no reason to add more yeast to the wine. If you have racked the wine off the sediment this is still okay. There will still be plenty of wine yeast to get the fermentation up and running, again. Adding more yeast is not necessary.
The duration of a secondary fermentation or conditioning phase can vary from as little as a week to over 6 months. Actual time will vary and you should let your taste buds and nose determine when a beer is ready for bottling. During extended secondaries, you should make sure your airlock does not dry out.
Residual sugar refers to the sugar left over in a wine following fermentation. Wine is made by adding yeast to grape juice, which contains sugar. The yeast converts this sugar to alcohol (wine) and releases carbon dioxide.
Proportion: the optimum sugar to water ratio is 2 pounds to 1 gallon. Yeast and time: the usual proportion is 1 cup yeast to 5 gallons of water. At this ratio, in the right conditions, the yeast will produce enough ethyl alcohol to stop fermentation in 14 days.
Sugar is optional; a little bit makes yeast happy, but too much—generally, more than 1/4 cup per 3 cups of flour—slows yeast down.
Likewise, too much sugar can result in yeast that becomes stressed out and gets overwhelmed by ethanol production, potentially creating too much alcohol, which will kill off the yeast, also halting the fermentation process.
Once you get the yeast on the water, add about a teaspoon of granulated sugar. Yeast is fed by sugar and this will help it multiply and activate with a little snack in its belly. Basically it speeds up the process.