Syrah - Day 9 - Sanitation

One aspect of wine making that has been unremarked upon up until this point is sanitation. Making wine is surprisingly dirty business. The grapes come out of the vineyard covered in everything and anything that came into contact with the grapes on the vines. This includes leaves, stems, tendrils, dust, dirt, spiders, and mold. The crushing process attempts to remove as much of these as possible, but even the best crusher/destemmers leave a fair amount of detritus in the must.

The vintner is then stuck trying to make wine out of must that includes more than just grapes juice, grape skins and seeds. The simple way to do this to kill everything that entered the wine with a dose of sulfites. This (hopefully) eliminates all the rogue yeast, bacteria and fungus that are inevitably present on the grapes. From the addition of the sulfites onwards, a winemaker needs to treat the must carefully, only allowing it to contact tools and additions that have been carefully sanitized. There are innumerable means of sanitizing your tools and implements, heating them above 160 degrees F, using chemical agents or only using items that come from a sanitary packaging or environments.

Heating all your implements above the temperature that kills microorganisms is not usually practical for a vintner. Many of the tools are plastic and would risk melting if heated above 160 F. Further it is not very convenient to have boiling water or a autoclave near your fermenters. Heating is much more practical for home brewing, where the residual heat of the wort is used to sanitize several parts of the process before fermentation is implemented. Since heat would break down many of the flavors wine makers are trying to capture this is doubly trouble some.

Therefore the main method of sanitation for wine making is chemicals that will kill microorganisms. The two primary chemicals I use are citric acid and iodine based sanitizers. Both come in concentrate forms that are available from home brew supply shops. They are both food grade sanitizers that when used in the appropriate concentrations should not leave a taste and effectively kill of potential contaminants. Other chemical sanitizers are available, but should be used with caution in food applications. Bleach is exceptionally effective at killing microorganisms, but it is very persistent and can end up killing the yeast, the microorganism whose growth winemakers are trying to promote. It also has a harsh taste that does not wash out easily. It should only be used for situations when equipment needs a harsh was, such as after a carboy has been allowed to mold after a long period of disuse, even then care should be exercised.

The best way to work with concentrated chemical sanitizers is to mix up a batch that's large enough for your needs and keep it in a container that allows you to reuse it multiple times to save time and chemicals.

The other means of sanitation is keeping sanitary substances from coming into contact with non-sanitary substances. Things like yeast additives and tartaric acid are additives that should not be heated or subjected to chemical sanitizers. If you are purchasing these additives to the wine from a reputable source (what did your mother tell you about buying chemicals off strangers in the streets?), you need to work under the assumption that the chemicals are manufactured and packaged in a sanitary environment. To keep the additives sanitary you need to ensure all the tools and containers the additives come in contact with have been properly sanitized. So when you are measuring the additives, the spoon and the container the additives are weighed in all need to be kept sanitary. It might be a pain, but it's the only way to ensure you're not adding a bacteria or fungus alongside the desirable additives.