Keeping Sane by Sanitizing

To make a great tasting wine without losing your mind, you need to control the winemaking environment and what goes into your wine. In this article, we're going to identify the four major categories of micro-organisms which can affect your wine; explain the importance of cleaning and sanitation in winemaking, discuss the differences between cleaning and sanitizing, identify the materials you should (and should not) use to clean and sanitize your equipment, explain the differences between sanitation and sterilization, and explain why sterilization isn't used in wine making. Micro-organisms: They're Everywhere! Wine is extremely sensitive to contamination. There are many different types of micro-organisms which live in the air and have a negative impact on your wine if they come in contact with it. Let's talk about the four major categories of micro-organisms which can affect your wine. First of all, there are yeasts which live in the air and on the surfaces in your home. These yeasts are similar in a lot of respects to the yeast that you add to the grape juice to start fermentation, but when you introduce a variety of yeasts to a winemaking operation, it is difficult to control the outcome, and therefore impossible to guarantee you will get the result you want. Wild yeasts are naturally occurring in nature and are not any threat to us as human beings in normal quantities, but as home winemakers we should think of them as undesirable participants in the winemaking process. The second category of organism which we don't want in our wine is bacteria. Bacteria are one of the major contributors to food spoilage, and once they start to reproduce and grow they are difficult to slow down or eliminate. Similar to wild yeasts, we look at most of the bacteria which exist naturally in our environment as the enemies of a positive winemaking experience. There IS a process called malolactic fermentation which calls for a specific bacteria to be introduced into the wine, but in all other cases we need to clean and sanitize our equipment thoroughly to keep bacteria out of the equation. The third category of micro-organism is fungus. In commercial winemaking, fungus can be introduced into the process from the grapes. Home winemakers who are using commercial kits are less likely to experience fungal contamination, because the kit manufacturers have treated the juice concentrate with anti-fungal agents. It is possible, however, for fungus to be present in your home, and therefore we need to make an effort to keep it out of our wine. The fourth type of organism we are trying to keep out of our wine is mold. Mold is a nasty bug which will ruin your wine in a heartbeat. Similar to fungus, it is less likely to be a factor in home winemaking than in the commercial sector, but it is still important to do what we can to prevent it from contaminating the process. Cleaning and sanitizing well is our best protection against both mold and fungus. Cleanliness in Winemaking So how do we know if something is clean? Any time we pick up a piece of equipment whether it be a bucket, a spoon, a measuring cup, or anything that is going to come in contact with the wine, we should always verify or be confident that it is first of all clean. A good rule of thumb is to use the same standards that you would use for food preparation in your kitchen. Wine is a food, and should be approached in a similar way. Let's consider the following scenario: you are having friends over to your house for dinner, and it is a fancy party. You want to serve the food on some special dishes you inherited from your grandmother. These dishes have been sitting in a cupboard or cabinet for several months. What is your first action? You would probably remove the dishes from the cupboard and wash them. You would either wash them in an automatic dishwasher, or by hand. You would likely use a common household dishwashing detergent, and would ensure that they were free of lint and dust. Now imagine if the dishes you wanted to use were on a shelf in your garage for several months before you wanted to use them. You would use the same approach to cleaning them, but you would put a little more attention on them by inspecting them for any dried dirt or other things remaining on the dish. For most of your equipment, hand washing with a standard unscented home dish detergent will be sufficient, provided you thoroughly scrub or wipe down all of the surfaces of each piece of equipment. Alternatively, you can put most of your equipment and a standard residential dishwasher and accomplish the same results. When cleaning your equipment, it is important not to use detergents which carry various smells or odors. You also need to make sure that you thoroughly rinse your equipment to remove any possibility of the detergent affecting the taste of your wine.

At its core, cleanliness is about what you can see, and smell. If you look at a piece of equipment and are confident that there is no dirt or other signs of contamination, then a quick rinse under the faucet is usually good enough. Cleanliness is a visual assessment of your equipment.

Sanitizing in Winemaking Once you are sure your equipment is clean, sanitizing is the next step. Any time you prepare a piece of equipment for use, you should always clean and sanitize it. When you sanitize equipment, you are exposing the surface of the equipment to a chemical which is hostile to all of the microorganisms we discussed earlier. Sanitizing is more important than cleanliness, because it addresses what you can't see. The best practice is to always assume that your equipment needs to be sanitized, even if you just finished cleaning it. The more disciplined you are about sanitizing, the less likely you are to experience problems with your wine that are caused by micro organisms. A clean bucket, for example, that is left open in your kitchen for 24 hours is suspect, because during that time it's been in contact with everything that's living in the air. What types of chemicals are used to sanitize wine making equipment? The most common sanitizers are potassium metabisulfite and sodium metabisulfite. These two compounds come in powder and tablet forms. The tablets are known as Campden tablets, and the powder versions are typically referred to by their chemical names. Potassium metabisulfite is sometimes referred to as K meta - K being the chemical symbol for potassium. Sodium metabisulfite and potassium metabisulfite are dissolved in water at a ratio of 2 ounces of powder per gallon to create a sanitizing solution. The next the next most popular sanitizers are solutions which are manufactured by a few different companies. StarSan is one of the most popular commercial sanitizers used by home winemakers. It is more expensive however than sulfites. There are other schools of thought which include using a diluted iodine solution, or strong liquors such as vodka to sanitize equipment. In my opinion, those solutions are good for spot sanitation but not for sanitizing products and equipment in bulk or in large amounts.

A word of caution: under no circumstances should you use chlorine bleach or isopropyl rubbing alcohol to clean or sanitize your equipment. Both products create significant health risks, and should be excluded from the winemaking operation.

Sterilize or Sanitize?

 The third term that you will hear people use sometimes in discussing how to prevent microorganisms from getting into your wine is sterilization. In the sterilization process, a piece of equipment is exposed to extremely high temperatures or very harsh chemical environments for the purpose of killing all of the micro organisms present on a piece of equipment. Everyone commonly associates sterilization with medical environments such as hospitals and lab laboratories. One of the principles behind sterilization is that once an object is sterilized it needs to be used immediately, and it needs to remain in a sterile environment to avoid contamination. 

In the winemaking world, the amount of effort required to sterilize something is not a good use of time, space, or money. Since we are making wine at home, the ability to keep something sterile is almost impossible, because our rooms in our house are not really clean rooms from the standpoint of sterilization. There is nothing stopping you from washing your equipment with boiling hot water to kill microorganisms on it. But you need to understand that after you finish washing it, it will immediately begin to get covered with microorganisms. Not because you have a dirty house, but because you do not have a sterile house. Sanitizing is are far as you need to go to protect your wine, and if you make it a habit, it will be enough to protect your wine sufficiently. To summarize, cleanliness refers to removing any dirt or other objects that you can see, proper sanitation takes care of the unwanted micro-organisms you cannot see, and sterilization is a an excessive and nearly impossible task for the home winemaker. What questions do you you have for me about cleaning and sanitizing during winemaking? Post your questions or observations in the comments below. In the next few posts, I'm going to answer some of the most common questions I am asked when people find out I'm a home winemaker. If you're not already on my mailing list, be sure to subscribe to receive notification when they are published!