Cleaning, sanitation and sterilization are critically important to producing quality wine and are key sources of wastewater generation. Cleaning is one of the most repeated and important tasks in a winery. It is time consuming, tedious, costly and potentially dangerous.
Changes in sanitation practices impact water use, wastewater quantity and strength, staff time and potentially wine quality and quantity.
Rinsing, cleaning, sanitizing and sterilizing are all different processes that happen under the umbrella of sanitization.
· Rinsing – when equipment is flushed with clean water
· Cleaning – removing dirt, debris and stains
· Sanitizing – the reduction of the microbial population to a safe level. Log 3 reduction (99.9% of microorganisms)
· Sterilizing - complete elimination of microbial life. Log 5 reduction (99.999% of microorganisms)
For cleaning the primary tools or variables that can be adjusted are:
· Mechanical Action
· Chemical Action
In most wineries cleaning is predominantly achieved through the use of sodium hydroxide based cleaners. Sodium hydroxide is an effective cleaner, but increases the salinity of the water and this cannot be removed during treatment. In many wineries an emerging alternative to sodium cleaners is potassium based cleaners that often have an increased cost.
The most common sanitizing practices involve using a combination of acidic and base cleaners that create pH changes ranging from 2 to 12.
Opportunities in Sanitation
Opportunities in sanitation will be discussed in greater detail in a follow-up report. Some practices that have been pursued at other wineries include;
1. Use substitute cleaners that have less wastewater impact
2. Capture and reuse of chemical cleaners
3. Use new technology to reduce energy, water, chemical use, staff time or total time
4. Identify opportunities to reduce tank transfers
5. Implement lees separation techniques to prevent any lees from entering into wastewater streams