Using Potassium Sorbate When Making Wine

Using Potassium Sorbate When Making Wine

Potassium sorbate (or k-sorbate) is a common additive used in wine kits. It’s usually added in the form of a power after fermentation has completed. But what does it do? What precautions should winemakers be taking when using it? What does Potassium Sorbate do? Simply put potassium sorbate is used to prevent spoilage by yeasts and molds in a finished wine. It does this by rendering these micro-organisms unable to reproduce. It is added to wines that have completed fermentation to prevent spoilage but also to prevent further fermentation of sugars added after fermentation such as when you back sweeten a wine. In the case of wine kits you would add potassium sorbate prior to adding the “f-pack” (grape juice concentrate). Usually you wouldn’t add potassium sorbate to a dry red wine because the sugars have been completely exhausted and the additive is not needed. Potassium sorbate should always be used at the same time with potassium metabisulfite. Together they make for a rather inhospitable place for micro organisms. The sulfites from potassium metabisulfite removes the oxygen from your wine to prevent micro-organisms from getting established while sorbic acid from potassium sorbate renders yeasts and molds unable to reproduce. Limitations of Potassium Sorbate While this additive does stabilize wines it does have three distinct limitations. First, it is ineffective against bacteria. If stray bacteria or lactic acid bacteria were to get in your wine while using only potassium sorbate it would not prevent spoilage or malolactic fermentation (as caused by lactic acid bacteria). The combination of sulfites and sorbate help reduce your risks of this as mentioned before. The second limitation of potassium sorbate is the length of time it is effective. Once added to wine it stays in the desireable form of sorbic acid only for a short time. Over time it breaks down into ethyl sorbate which can add notes of pineapple or celery to your wine. The change into ethyl sorbate is not preventable. By using potassium sorbate winemakers are putting a definite shelf life on their wines before they pick up these off flavors. The third limitation is that it reacts poorly with lactic acid bacteria. According to my research it can produce strong geranium odors which most wine drinkers consider a flaw. Because of these limitations many wineries do not use potassium sorbate. They opt to stabilize with sulfites only an rely on their ability to properly sanitize everything to prevent spoilage. Interestingly, wines with potassium sorbate may not be classified as organic. Precautions When Using Potassium Sorbate (Please Read This!) Despite these limitations kit manufacturers include potassium sorbate in their wine making kits. This is to make sure the wine is as stable as possible even if there were some equipment sanitation lapses. Potassium sorbate should be stored in a dry area away from heat and light. Storage temperatures should not exceed 100 degrees (F). Like many additives potassium sorbate is an eye irritant. Should you get any in your eyes flush them with water for 15 minutes and get medical attention. Lastly, and most importantly, paper or cloths that have absorbed potassium...

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Stabilizing Wine

Closely related to the clarifying wine, is stabilizing it. Many of the same methods used for clarifying wine are also used to stabilize it, with a few additions. What is an unstable wine? By unstable we mean that the wine is susceptible to spoilage. The most common causes of spoilage are oxidation, unintentional second fermentations, and excess protein. Spoiled wine may taste old and weak in the case of oxidation. Otherwise spoiled wine may take on a rancid or rotting flavor profile. None of these are the least bit desireable. Except for oxidation spoilage mainly occurs due to uninvited micro-organisms. These organisms may have come in with the fruit or may have stuck around on a piece of equipment that didn’t get sanitized quite well enough. How to Stabilize Wine There are different stabilization methods for different types of spoilage. The simplest forms of stabilization being racking and filtering. Both serve to remove undesired yeasts and other micro-organisms. Additionally, there are any number of chemicals that can be used to kill off these organisms so that there’s not a party in your wine after you’ve bottled it. For example sulfur-dioxide is used to kill of yeast cells to prevent a second fermentation. Bentonite is used to remove excess protein (also known as hot stablization). Cold stabilization is when you reduce the temperature of your wine to nearly its freezing point to purposefully form tartrate crystals you can then remove through racking. These harmless crystals form when tartaric acid precipitates out of the wine. They have no effect on the flavor but they can put people off because they look like broken glass. Oxidized wine, however, is permanently ruined. There’s no reversing the effects of too much oxygen so be sure everything is tightly sealed during the aging process. What Methods Should I Use? The method of stabilization you use on your wine depends largely on what issues you’re facing. By in large the best preventative stabilization method is the addition of sulfur-dioxide(SO2). Whether introduced as a gas or in tablet form this chemical kills off yeast, malolactic bacteria, and many other micro-organisms. Adding SO2 should be part of your wine making process. Aging your wine prior to bottling will give many stability issues time to show their faces. You don’t want to find out you’ve got stability issues after you’ve bottled. Any treatments after bottling will take a lot of work and introduce far too much oxygen. If your wine is getting cloudy or tartrate crystals are forming its time to start clarifying and stabilizing. Start out by racking and, if you’re through all your fermentations, add SO2. In the case of tartrate crystals cool your wine to near its freezing point and rack it. After any clarification or stabilization treatments give it more time to see what happens. You may need to do more than one stabilization. Being able to see your wine is a key element here. Aging in oak barrels can make it hard to tell what’s going on. Careful inspection with a wine thief and your test kits is your best bet. Lastly, taste your wine before bottling. In...

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