By: Tom Payette, Winemaking Consultant
In the last issue of The Grapevine Magazine this section addressed how to clean a wine tank. In reality a clean wine tank is of little benefit if the means of getting the juice or wine to that tank is a contamination source in itself. Just as much diligence needs to be applied to the wine transfer hoses to insure a wine arrives at it’s destination in as microbial free state as it left the previous storage container.
The chemistry of cleaning the winery hoses is very similar to cleaning the wine tanks or most anything else in the winery for that matter. One must have physical cleanliness first. In this case this means all of the solid particles are removed from a surface prior to or in conjunction with a high pH cleaner. Once dirt is removed from a surface the chemical may react on that surface to clean and kill certain microbes that will not survive in the harsh environment of a higher pH. After physical cleanliness is achieved and the high pH cleaner has cleaned the surface, a low pH cleaner such as citric acid may be used to neutralize the high pH cleaner and to kill certain microbes that will not live in those lower pH environments. Make sure all cleaners used are suitable for the wine industry and are safe for the winery.
All safety material to include but not be limited to:
• Safety goggles
• Rubber gloves
• Rubber boots
• Hat and/or chemical resistant rain gear
• High pH cleaner (such as Soda Ash)
• Low pH rinser (such as Citric acid)
• Material Safety Data Sheets (MSDS or equivalent) for all chemicals used.
• Eyewash station or portable eyewash
A light citric and water solution (2 tbsp per 2 gallons of water)
Other items needed will include:
• Pump that will handle warm water and the chemicals desired.
• Wine transfer hoses that will stand up to warm water and all chemicals used.
• pH meter (optional but the winery really should have one anyway)
• Sponge balls at diameter(s) needed for hose inside diameter. (See photo)
• Tub for water circulation
• Water Source
Apply all safety gear and prepare a light citric and water solution in a bucket to set aside. This is a light “lemonade strength” water that may come in useful should some of the high pH cleaner come in contact with your skin. [Roughly two tbsp. of citric in two gallons of water depending on the tap water pH] Select a good positive displacement pump from the cellar that will help power a sponge ball through the wine hoses to be cleaned. Collect all of the wine hoses you want to clean. The author prefers to do this on the crush pad just after harvest, in the spring and just prior to harvest at a minimum.
1. Apply all safety gear necessary to be safe while doing the tasks described. This is an internal winery decision that the winery will need to address.
2. Move all equipment outside that needs to be used to clean the hoses.
3. Have the “lemonade strength” bucket of water mixture mentioned above placed close by and in a spot that can be easily located.
4. On the suction side of the pump assemble a short section of hose. This hose should be long enough to span from the tub of cleaning water to the pump.
5. Assemble the other remaining sections of hose on the pressure side of the pump from the largest internal diameter size to the smaller internal diameter size. An example may be having all the 2” sections connected, then a reducer to the 1.5 inch sections down to 1 inch and three quarters and so on.
6. Once all the connections are made, start to fill the tub with clean fresh water. Warm, not hot, may be the best water for this process. A good target temperature should be in the 90 degrees F. temperature range.
7. While the tub is filling, one may start and stop the pump to fill the lines with water. Memorize the direction of the flow since we will always run the pump in that direction for this exercise. [This is important so we do not suck the sponge balls we will using back into the head of the pump.]
8. Once the lines are full be sure to pump about 10 gallons of water out on the floor to eliminate any obvious solids that may have collected in the hoses during storage. (This is especially true if wine hose is stored curled up on the floor – not a recommended way to store winery hose).
9. Once the winery lines are completely full with water one may stop the pump.
10. Gently disconnect the discharge side of the pump from the pump head fittings and insert the proper size sponge ball to clean the smallest size internal diameter of hose assembled in this set up.
11. Reconnect the discharge side of the hose back to the pump.
12. Turn the pump on in the direction to push the sponge ball through to the lines to be cleaned. Leave the discharge end of the hose in the tub for the time being to conserve water.
13. Follow the sponge ball visually, if possible, through the maze of hose making sure the suction line has a continuous source of water supplied.
14. Once the sponge ball reaches the specified diameter of hose it is designed/sized to clean, keep an eye on the hoses since one may see a slight pressurization and accordion type movement in the hoses at this time. Be aware fittings could be blown off under pressure.
15. As the sponge ball makes its way through the lines and the ball has about 7 feet more to go, remove the discharge line from tub of water and allow the water to exit onto the floor or crush pad. You will notice a “tea like” to “coffee like” colored water will start to exit the discharge line just before the sponge ball exits. This is true for even any well kept hoses that have not been cleaned in this fashion for over one year. It is inevitable beyond anyone’s sanitation programs.
16. Recapture the sponge ball and run the ball through again. It will still clean a bit more on the second and third pass.
17. Once one feels this section of hose has “mechanical cleanliness” one may disconnect that size diameter line from the assembly.
18. Select the proper size sponge ball to clean the next diameter size section of hose near the end of the assembly and repeat the procedure gaining mechanical cleanliness on each diameter size hose working your way up to the largest size line.
19. Once all of the lines are cleaned be sure to swap out the suction side supply line with a cleaned section and run the proper sized sponge ball through that section.
20. Now that mechanical cleanliness is achieved, one may reassemble all of the hoses and start the pump for a circulation.
21. Once the circulation is started in the clean tub of water, one may add a high pH cleaner. Always dissolve any solid cleaners in water first before adding to a tub of water. (This will take some trial and error on the operators part to establish just how much may be needed) [Use a pH meter to determine this strength needed].
22. Allow this high pH solution cleaner to circulate for an adequate time. This may be near 15 minutes depending on the length of hose line, sizes, speed of pump and the amount of water in the circulation tub.
23. Once the operator feels the hoses interiors are well exposed to this higher pH water, the operator may then flush the hoses out with copious amounts of fresh water.
24. After a fresh water rinse one should continue to circulate water and add a low pH cleaner, such as citric acid, to the mixture to insure the high pH water has been neutralized.
25. After this neutralizing step, it is best, once again, to do a fresh water rinse.
26. The hoses should now be clean, but not considered sterile, to the satisfaction of most wineries’ sanitation programs.
27. One may disconnect all the winery hoses and store them properly to drain dry. Resist rolling hoses up on the floor and laying them flat because water, moisture and insects/rodents may have a better opportunity to become an issue for them.
When selecting hoses for use at any given time, it is best to make the assembly of the hoses and to flush the hoses or clean them in some fashion just prior to pumping juice or wine. This will clean out any items from the hoses or pump that should not have been in them.
Just prior to harvest consider performing this operation on the hoses but perhaps take the step a bit further. Once the hose lines are cleaned, remove the fittings from the ends of the hoses and either clean them vigorously or cut off the portion of the hose that was in contact with the fitting. Clean the stainless fittings until they are sparkling and then re-install the fittings and tighten the clamps properly. (Note: when putting hose clamps on have them pull and installed in opposing directions to get a better tightening grip. Also, apply the clamps as close to the end of the stainless fitting that is inside the hose line. If this is not done wine may seep between the fitting and the hose line, especially when ballooning under pressure, and forcing wine between them. Over time, spoilage will occur which will result in a cross-contamination source for every transfer or operation performed with that set of hoses in the future.
Set up your hose cleaning operation to be as easy as possible and make sure the cellar staff is keenly aware of your expectations. Hoses that are not cleaned properly should not be used and instructions to clean them again would be prudent. Remember, wine is a product that you and others will drink. Use hoses that are cleaned with the same amount of dignity that you would want your foods and other beverages prepared in.
Mono type pumps have been known to pass the mentioned sponge balls easily provided the pumps are not smaller than the actual ball diameter used.
Be sure to keep a watchful eye on the diameter of the sponge ball and the diameter of the wine line you are trying to clean.
Do not run the pump while dry or damage may occur.
Use a pH meter to determine the pH of your cleaning solutions.
Smell your hose before you use them for a wine transfer.
Look inside your hoses before using. What do you see?
Like tanks and other items, don’t let dirt, juice or wine dry on them. Clean immediately after use (inside and out).
Always store the hoses so they will drain and dry completely. Hoses should not be curled up on the floor with potential standing moisture inside them. Being on the floor also makes them easily available to any winery critters or insects.
If one has cleaned the winery hoses and removed the fittings, the author recommends a way to test their strength. Assemble all the hoses together with a valve at the very end of the discharge side. Circulate fresh water with no chemicals for cleaning. After about 5 minutes of circulation take the discharge side of the hose from the circulation bucket and start to slowly move the valve toward the closed position for a brief moment. Be aware at this moment pressure will be building inside the transfer lines and to be clear of any hoses that may pop off their fittings. Be very careful with this procedure and use common sense knowledge not to shut the valve all the way creating extreme pressure.
Have two people around at all times for safety.
• Always keep the winery hoses clean.
• Use a sponge ball to create mechanical
• Visually inspect and smell all hoses after cleaning and before using for wine transfers.
• Obtain and use all safety gear needed.
References: Verbal conversations with Jacques Boissenot, Jacques Recht, Joachim Hollerith and Chris Johnson.