Friday, June 5, 2009
Why Pasteurize? Once the bottle is closed pasteurization will kill the microogranisms (including yeast) in the beer, cider, or wine. Microorganisms and yeast all have a "kill point" which is a product of temperature and time. Once those organisms stop "feeding" on the carbohydrates the product is "Stable" and thus its flavor is stable. Does the pasteurization process itself change the flavor? Experts say "Yes, but not dramatically". Seems natural if any process affects the product it affects the flavor.
This is what is called "vat pasteurization" or "immersion pasteurization". Turn your hot water heater to high for this, and find a sink, cooler, or tub that will hold the product desired. Pasteurization requires that an elevated temperature be held for a duration of time. So in this excercise, hot water must continually run into the "tank" at the same rate it is allowed to "leak". A home hotwater source is generally about 165F.
Put the product in the tub, sink, or cooler. Fill it with hot water (assumed to be 150F-160F). Once full, create a slight draining effect and continue to fill with hot water. For 12 oz bottles, keep the bottle in this state for approximately 45 minutes for 750 ml bottles keep the bottles in this state for approximately 60 minutes. A floating thermometer is always a good idea and confirming that the vessel is above 145F is a good idea.
Once the time has elapsed, remove the product from water and move directly into refrigeration for rapid cooling (i.e. remove all heat from the product).
Home pasteurizing in this way does not kill every flavor changing microorganism but kills most. At this point most products should maintain their flavor for roughly 8-12 months in an unrefrigerated environment. The "comeback rate" is a function of the temperature the product is stored at (i.e. growback rate at room temperature is higher than refrigerated). This process will consume roughly an hour to execute and will provide up to 12 months of flavor stability.