Granular potassium metabisulfite (or metabisuphite) makes it possible for the small-volume winemaker to make fresh (unoxidized) wines that will age well with only a small likelihood of spoiling.. Alternately, those making wine for their own consumption may wish to minimize (or even completely avoid) additives. There is no doubt that some people have a strong negative response to sulphites. These substances are common in many types of food and in the past were sometimes added in quite large amounts to wines that needed to survive the high temperatures they experience in shipping. People with specific allergies or certain medical problems (such as asthma) may need to avoid all such foods and most wines. If you suspect that you have such a problem then you need to do more than just avoid adding sulphites to the wines that you make as all wine contain some sulphite (see note immediately below). To be safe, you will also need to test (kits are available) the wines you make before drinking them !

All wines contain sulphites. Even if no sulphites are added during winemaking, wines naturally contain sulphites. This is one of the reasons why commercial wine producers carefully measure the amount of sulphite present during several steps of the winemaking process. They also avoid applying with sulphur sprays just before harvest. Sometimes there is even too much sulphite before anything is added by the winemaker ! Fortunately, you will find that this is not a very common problem. If you want to adopt some form of sulphite treatment, the tool will help you to add minimal amounts. The text provided in the tool details several reasons for adding sulfite (or not)..

Sulphite Tool

Summary: The best way to reduce the use of sulphites is to make wines that do not need very much in order to ferment and age without spoilage. To do this, make red wines with robust amounts of tannin, alcohol and acid. Use only very high quality (no more than just ripe enough) fruit with no rot or mold. Test for pH and keep it low. Avoid exposure to air. Add nutrients to the primary fermentation and make sure the (high quality) yeast gets an early start. Make dry wines. If you do this, adding sulphite at crush time is probably not required and only very small amounts need be added when racking and bottling. The risk of using zero or very low amounts of sulfite is that your wine may oxidize or spoil before you can drink it. Wine was made traditionally for probably thousands of years without added sulphite. This is one of the reasons that in classical times Roman soldiers received a regular vinegar ration. What else could they do with all that wine that turned to vinegar by January?

Sulphite Wash at Crush Time. There is another way to sulfite at crush. Grapes delivered by truck often arrive with quite a bit of grit etc. If you are fermenting fairly small amounts you are probably carefully hand selecting your grapes anyway. This is the method that I prefer, particularly if I want to "cold soak" the grapes for a day or two, before start of fermentation. Make up a strong potassium metabisulphite solution containing about 15 [ml] (3 teaspoons) of granular bisulfite per liter. If you mix this in a gallon jug (either kind) add about 12 to16 teaspoons. When washing the grapes add about two cups (1 cup equals 250 [ml]) of this solution to each pail of water you clean the grapes in. Wear vinyl gloves (NOT latex which will contaminate the must) or the sulphite will cause skin erosion. YOU MUST THEN DRAIN THE GRAPES BEFORE CRUSHING which gets rid of the large amounts of water and most of the sulphite introduced in the washing process. The advantage of this method is that the amount of sulphite that ends up in the wine is fairly small and the entire surface of every grape has been exposed to the sulphite rather than the sulfite being dispersed into a large volume of must after crushing. This way very little sulfite becomes permanently bound to the sugars etc that are found INSIDE the grapes. If you have never cleaned grapes before fermentation, you may be shocked by how quickly dirt accumulates in the wash pail ! Just add a couple cups of sulphite solution each time you change the water.