What are those packets anyway?
Wine kits are a very popular way to make wine. I love them. Why? Well, wine kits have everything you need to make six gallons of wine. All the ingredients, finings and stabilizers are included. Hey, they even include the instructions at no extra charge. Another reason I love making wines from kits is because I do all-grain brewing for my beer. I don’t need TWO hobbies that are time-consuming and require a lot of thought.
Wine kits come in all shapes and sizes but in the end virtually all of them make 6 gallons, or 23 liters, of wine and they all come with a set of common ingredients and I’m going to explain what they are and their role in the winemaking process.
So, let’s start with the most obvious, the grape juice. All wine kits include grape juice. Without it, we wouldn’t have wine. The amount of juice varies depending on the kit, ranging from 7 to 23 liters of juice. Wine juice is flash pasteurized to keep it from spoiling and varying levels of concentration also help protect the juice. The smaller the bag of juice, the more concentrated it is, requiring more water to reconstitute it to the desired 6 gallons of finished wine. The larger bags of juice tend to have more total dissolved solids adding more complexity and body to the wine. Regardless of which kit you are making, the juice is the most important factor in the final outcome of the wine. For help in deciding what kits are best for your needs, please read my blog entry, Are wine kits created equal?.
The next ingredient that is almost as important as the juice is the yeast. Without yeast, grape juice is just that, expensive but great tasting grape juice. The job of yeast is to metabolize the sugars in the juice into alcohol. I get lots of questions about the yeast that is included with the kit. The most common being, “Should I get a better yeast than the one that is included with the kit?” My answer is no. Use the one that comes with the kit. Think of wine kits manufacturers as a high tech winery. They put a lot of work and research into their wines and go to great care to pick a yeast that best suites the wine you are making. Why would they risk their product buy putting in a wine yeast that wasn’t the best one for the kit? After all, they want you to love the end product and buy more. So stick with the yeast they give you. It will work great.
In addition to the juice and yeast, wine kits also include finings and stabilizers. Let’s talk about what these do to the wine.
Bentonite is clay that is used as a fining agent to clear wine. It has a negative electrostatic charge. This attracting charge along with hydrogen bonding causes suspended particles in the wine to cling to it as it settles. Bentonite is a very effective fining agent that grabs onto yeast, tannins and protein particles drops them out of solution. It also helps to reduce off-flavors and aides in the prevention of oxidation. Bentonite is added in the first step of the winemaking process.
Potassium Sorbate is referred to as a “wine stabilizer”. It is added after fermentation is complete to create an environment that is inhospitable to wine, preventing it from re-fermenting. Potassium Sorbate is important for sweet wines. Yeast live on sugar. If you want to make a sweet wine, the easiest way to ensure that it will not continue to munch on the sugar is to add sorbate. If your wine kit is a dry wine, you can leave the sorbate out of the wine as long as you verify fermentation is complete before bottling. I never add sorbate to my dry wines but I ALWAYS add it to my sweet kits.
Potassium Metabisulfite is a granulated powder that releases sulfur dioxide when dissolved in liquids. It is a very important part of the winemaking process as it is a bacterial inhibitor that protects the wine from spoilage, particularly from the Acetobacter bacteria that turns wine into vinegar. Potassium Metabisulfite also protects against oxidation of your wine which can affect the flavor and color. If you are planning on aging your wine for an extended period of time, you should add additional sulfites to your wine. Refer to the wine kits instructions for suggested doses.
All wine kits include a liquid fining agent. Typically, the kit will include kieselsol/chitosan or isinglass.
Kieselsol/Chitosan is a combination of two fining agents. Chitosan is derived from the shells of shrimp and other crustaceans. It is a great flocculating agent in wines. It precipitates solids and is a very efficient clearing agent. Kieselsol is a byproduct of the glass industry. The primary use of kieselsol is for clarification and as a replacement for tannin during gelatin fining of white wines. Kieselsols are negatively charged and electrostatically bind to and adsorb positively charged proteins and initiate flocculation and settling. Used together they are fast and effective in clearing wine.
If your kit doesn’t include kieselsol/chitosan, it will probably have isinglass. Isinglass is obtained from the dried swim bladders of fish. It is a form of collagen used mainly for the clarification of wine and beer. It works much the same way as kieselsol/chitosan and is thought of as a polishing fining agent for wines that are already fairly clear.
So there you have it. The ingredients included in virtually all wine kits that are out there. In a future entry I will talk about other ingredients that can come in wine kits such as grape skins and oak chips.
Please feel free to comment with questions or feedback.
Cheers,
Desiree Knott
High Gravity Homebrewing & Winemaking Supplies
7164 S Memorial
Tulsa, OK 74133
(918) 461-2605
desiree@highgravitybrew.com
http://www.highgravitybrew.com
About The Author
Great article! I do, however, have a different opinion about using the yeast sachets that are provided with the kits. For the more experienced winemaker, the only ability you have to alter the outcome of the finished wine lies with the yeast. If you would like a sweeter wine, the use of a less attentive wine will result in a higher residual sugar percentage. This seems to be a greater benefit when working with fruit wines where you desire more fruit flavor. Many times, when I make a wine from a kit, I do not know how the wine was “designed”, So I will use an aggressive yeast to eat more available sugars, and then sweeten back to my desired sweetness level.