For making sake, as with other fermented beverages, cleanliness and sanitation are extremely important. The reason for this is that a goodly part of the flavors come from the bugs in the ferment. When the bugs are the ones we want we get the flavors we desire but when others invade the party they produce off flavors that lower the quality or even ruin the beverage altogether.
In sake using the sokujo-moto method there is one player (bug) that we want to encourage while restraining all others. The player we want is the yeast we introduce ourselves. When using the yamahai-moto method there are two main players; lactobacilli and yeast.
Given this, how do we go about restraining all the other bugs? Well, restraining these other bugs is a key part of sake brewing. It begins before we even start to prepare the ingredients; it starts with the cleaning of the equipment. Once clean, we sanitize the equipment as needed throughout the process. We control the pH and temperature to provide an environment discomforting for most bugs and finally, when not making namazake or unpasteurized sake, we pasteurize the sake at least once, usually twice.
Here I want to cover the basics of sanitation needed for making sake. To sanitize something, it must first be clean. If not, bacteria (bugs) have places to hide preventing us from satisfactorily sanitizing. What does it mean to be clean? It means that all the foreign matter has been removed and none remains. However, this does not include bacteria and other micro-organisms that may be present. Once clean an object can be sanitized. Sanatization kills off many of these bugs so that they remain only in negligible levels. Removing, killing and simply destroying 100% of these critters is called sterilization.
For most elements of making sake we only need to worry about cleaning and sanitizing. Sterilization is important for yeast management but once we have the needed yeast in hand we are good to go; no more sterilization required.
OK, so what do we need to know to clean our equipment? Well, cleaning is all about applying the effort needed to remove all the foreign matter, the places where bugs hide. To lower the effort required to do this we can use chemicals; detergent, bleach or something called percarbonates are the most commonly used.
It is important to avoid cleaning detergents / agents with perfumes. These can be absorbed into plastic and later your brew. It is also important to rinse thoroughly to remove the lingering film common to detergents. Any remaining film can negatively affect the taste of your sake.
Bleach can be mixed with cold water to produce a caustic agent (high pH) that will dissolve organic deposits; 1 tablespoon per gallon works well. However, you must be careful when using with metals because its corrosive powers will pit metals if left in contact for too long. Brass and copper are the extreme cases here and should not be cleaned using bleach.
Percarbonates make up a group of cleaners that are specialized for the food industry and commonly found in use by brewers. The one that comes to my mind is, PBW, Powder Brewery Wash. This product is very effective while rinsing away easily. Use 1 tablespoon per gallon.
Use any of these cleaners or none of them but be sure your equipment is clean. Once you have done this, and you are just about ready to use your equipment it is time to sanitize it. Both chemicals and heat can be used to sanitize. Bleach, Iodophor and a product called Star San are all good chemical choices.
Bleach mixed with water at a ratio of 1 tablespoon bleach to 1 gallon of water provides the needed killing power to sanitize an object left to soak for 20 minutes. Technically speaking, you don’t need to rinse the object after draining but many will rinse with boiled water.
Iodophor mixed with water provides a very nice sanitizer. No more than 1 tablespoon per 5 gallons of water is required and it is no more effective at higher concentrations. Whereas you need to soak objects in bleach for a considerable time, only 2 minutes are needed to soak them in iodophor. Neither, do you need to rinse after soaking in iodophor. There is one drawback however, after prolonged exposure, iodophor will stain plastics. The “damage” is only cosmetic and does not affect the suitability of your equipment.
Star San, an even faster acting sanitizer, is made specifically for brewing by the same people who make PBW. This product will sanitize your item in 30 seconds and like those above, does not need to be rinsed away.
While plastic items are not as amenable to heat sanitation, glass and metal items are. For example using your dishwasher is a good way to sanitize bottles en mass. As discussed, all items must already be clean. While doing this it is best not to use any detergents, just let the dishwasher go through its cycle and the heat and steam will do the sanitization.
While there can be a lot more said about heat for sanitization and even sterilization the only other use most may do is a from of “flaming” an item. This is a quick way to sterilize it before use. I use this for quickly sanitizing my stirring spoon.
This basic information is everything you need to know for your sake brewing. While all your equipment should be clean, only those items that come in contact with the sake as it progresses through the brewing process need to be sanitized.