Please click on an FAQ link below to view information regarding that question.   Question: I started making my own wine, and I’m a little leery about using preservatives. Are they absolutely necessary in wine?   Answer: Preservatives (sulfites) are an important part of wine making. Don’t worry about adding them to your home-made wine. Not only do they keep wine from developing infections, they also keep the wine from oxidizing. If you are concerned about the use of sulfites in wine read on! The preservative we most often recommend is sulfite, since it occurs naturally in small amounts during fermentation. Sulfites are your friend. Not only do they keep wine from developing infections like film yeast, mold, and acetobacteria (vinegar bacteria), they also keep the wine from oxidizing. Without the use of sulfites you have to be terrifically careful to keep all of your equipment very sanitary and you still have to drink your wine up as quickly as possible before it spoils. Many people worry that they may be allergic to sulfites. True sulfite allergies are very rare. It’s more likely that they have been exposed to a high level of sulfites in the past. In the 1970’s restaurants would douse their salad bars with 2000 PPM (part per million) sulfite solutions in order to keep the produce fresh. Mixing this with acidic foods, such as salad dressings or vinegar, would cause the salad to release clouds of sulfite gas, provoking unpleasant reactions. What most people describe as a sulfite headache is a reaction to bio-amines. These are compounds formed in wines for various reasons, one of the most common being malolactic fermentation in the presence of sugar. Some commercial wineries start malolactic inoculation before the end of alcohol fermentation, guaranteeing the formation of bio-amines. Since most wine kits don’t go through malolactic fermentation, they do not form bio-amines, and consequently don’t provoke allergic reactions. Potassium Metabisulphite is also a stable source of sulfite in winemaking. The use of sulfur compounds is not a recent innovation. The Dutch shipping companies popularized the use of sulfur in the 16th century by refusing to ship any wines not treated. They insisted on the use of sulfites because the treated wines were the only ones that survived a long sea voyage without spoiling. Sulfites work by releasing free sulfur dioxide, which inhibits yeast, mold and bacteria. It does this in two ways: one, it kills some of the organisms outright, and two, it blocks the surviving organisms’ ability to reproduce. If your winemaking equipment is physically clean and you’ve rinsed it with a sulfite solution, nothing will grow on it.   Question: What’s the difference between cleaning and sanitization? Why are they so important to winemaking?   Answer: 90% of all winemaking failures can be traced to a lapse in cleaning or sanitization and yes, they are two different things. Cleaning chemicals removing visible dirt and residue from your equipment. Some good cleaners are B-Brite, One Step, and Easy Clean. Sanitizing is treating your equipment with sanitizing chemicals that will eliminate, or prevent the growth of, spoilage organisms. You cannot sanitize anything unless it is clean. Some good IO Star and Star San. Everything that comes in contact with your wine must be clean, and properly sanitized, from the thermometer to the carboy, from the siphon hose to the bung and airlock. One single lapse could cause an entire batch to turn out poorly.   Question: I just racked my wine and it stinks like rotten eggs! Can I fix it? HELP!   Answer: Hydrogen sulfide (H2S) is the rotten egg odor you smell, and it usually forms at the end of fermentation. Most home winemakers won’t notice a smelly problem until the first racking. If you do smell rotten eggs, the quicker you can act, the better your chances of saving the wine. If it is too long a time before you treat the wine, hydrogen sulfide will react with other carbon compounds in the wine to create mercaptans, and later into disulfides. These are extremely difficult to remove from your wine once they are present, so the faster you can detect and treat your wine for hydrogen sulfide, the better. Many sources suggest that you add copper sulfate to your wine, but Midwest advises against this. While a very, very, VERY small amount of copper sulfate will take care of your H2S problem, it is poisonous. Big wineries use copper sulfate, but Midwest suggests a kinder, gentler approach, using chemicals that most winemakers already have on hand. First, measure the level of sulfites in your wine using the SO2 Test Kit (#8262). If the wine is deficient, treat the wine to 50 p.p.m. sulfites. Next, rack the wine two or three times, making sure to splash it around a lot as the wine is transferred between vessels. This aeration introduces oxygen to the wine, and will help counteract the hydrogen sulfide. Replace the airlock, and let it sit overnight. This should take care of the problem in most cases, but if it still stinks, perform these extra steps: Buy a piece of copper flashing from from a home supply store. Hold the piece of copper in the neck of the carboy while the wine is being racked, so that the wine runs over the copper surface and into the carboy. Fine and/or filter the wine. By now, that stinkiness should be greatly reduced. If you STILL detect a smell, try gelatin finings (#8330) in the amount stated on the package. After fining, we suggest running the wine through a filter. The Vinebrite Filter (#7145) is fairly inexpensive, and works pretty well. If you’ve done all this to no avail, you could try using copper sulfate. But BE CAREFUL! Add NO MORE than 0.5 ml per gallon. Afterward, be sure to fine the wine with bentonite (#8310) or Sparkolloid (#8363) according to package instructions. Either of these will remove the copper sulfate. Then filter to remove the fining agent.   Question: What is the purpose of using Campden tablets?   Answer: Initially, Campden tablets are used to kill off any potentially harmful bacteria that may may be present in the base ingredients used in winemaking, and to discourage any wild yeast from gaining a foothold. Campden will not kill yeast, but it creates an environment inhospitable to them. As sulfur dioxide (SO2) is released into the must and the atmosphere above the must dissipates, the environment inside the fermenter slowly changes and the yeast can grow, but by then our cultured wine yeasts, which are more tolerant of SO2, have gotten a good start and “crowd out” the wild yeasts, use up all the dissolved oxygen, and consume all the fermentable sugar and nutrients. In the end, there is nothing left for the wild yeasts and they die without propagating. When we rack, we add oxygen to the wine and expose it to airborne microorgamisms we’d rather keep out of the wine. This causes the wine to oxidize if antioxidants are not present to prevent it from happening. SO2 is a powerful antioxidant but it dissipates over time, so we add more Campden to the wine when we rack to prevent oxidation. The same antioxidant protects the wine from airborne bacteria and molds. We also add Campden at the time of the 1st racking, the 3rd racking, the 5th racking, and so on. We skip the 2nd, 4th, 6th, etc. rackings unless one of them is the last racking before bottling. We always add Campden (or metabisulfite salt) at the last racking because the wine is particularly vulnerable to infection (from the air, inside the bottle or on the cork) when we bottle it.   Question: What is the proper procedure for using Campden tablets?   Answer: Initially, crush the Campden tablet with a glass mortar and pestle and stir the powder directly into the must. Before racking, crush the tablet and pour the powder into 1/3 cup of HOT water. Use a sanitized bamboo whip or a stainless steel fork to beat the powder into the water. It may take a few minutes, but it will all dissolve if you work at it. This cools down the water quite a bit. When dissolved, use a wine thief (or siphon tube) to draw off a cup or so of wine and mix this with the sulfited water. This sometimes causes small lumps to form, so whip the mixture a little more and then pour it into the receiving jug or carboy. Then rack the wine into that secondary.   Question: Why are there different types of Campden Tablets - potassium metabisulfite and sodium metabisulfite? Which one should I use and when?   Answer: The main difference between the sodium and potassium metabisulfites is the carrier element. Their effects are virtually the same, with potassium metabisulfite being slightly more potent when it comes to contributing SO2 gas. Most home winemakers will use sodium metabisulfite as an equipment sanitizer as it is cheaper. In the American diet, there is rarely a shortage of sodium, so commonly, winemakers use potassium metabisulfite to sulfite their wines to keep extra sodium out of their diet.