Winemakers in the industry were consulted to point out the most common mistakes that can occur in and around cellars. Here are a few guidelines to avoid some of these problems.
Clear work instructions
There is no chance of being 100% certain of exact execution when giving work instructions orally. It is extremely important for those who issue the work instructions, as well as those receiving and carrying out the instructions, that the task brief must be clearly provided in writing. Note the following in particular:
- Use a pen instead of a pencil to write down instructions.
- It is a good practice to place written (or typed) work instructions in a plastic sleeve cover on a clipboard, as water/fluids are often worked with in a cellar. If the work instructions get wet, there is a possibility that it can be read incorrectly.
- If a mistake is made in the instructions, draw a neat line through the mistake and write the correct instruction next to it with your signature to authorise the change.
- Pay attention to the clarity of your handwriting. Numbers like 1, 7 and 9 in particular can be confused if not written clearly.
- Make 100% sure that the unit of the additives indicated is clear, e.g. ml versus litre and gram versus kg. If you write down 100 cc sulphur gas, ensure that the two c’s cannot be interpreted as zeros.
- Ensure orally that both parties (those who issue and those who receive) have the same understanding of the written instructions.
Harvest equipment
During the harvest season, especially in the area where grapes are received, equipment like pitchforks, shovels and long scrapers for emptying pressing bins are regularly used. These tools usually become very sticky, difficult to clean and a breeding ground for harmful micro-organisms. An easy way to address this potential problem is to keep a tub with a water-acid solution and a bit of meta in the pressing area. Ensure that these pieces of ‘outside equipment’ are regularly dipped in the tub, e.g. every time the cellar team goes on a break like lunch or tea time.
Tank accessories
Tanks are usually washed very well and regularly, but unfortunately the cleaning of ‘extras’ is sometimes neglected. These extras include items like tank rubbers, sample taps, sight glass valves, sight glasses, bottom valve, racking valve, racking arm, the top lid, its rubber seal and the turret. Last-mentioned can be a collection area for foam from the fermentation, which can harden making it difficult to wash off. A good practice is to make a list of all these items, which can then be ticked off once cleaned.
Leaking tank doors are probably one of the most irritating things that can happen in a cellar. Tank doors are mostly hugely specific in terms of which tank they fit.
What often happens is that tank doors are removed to be washed, and then not re-attached to the original tank. Marking the doors with the corresponding tank number is a simple and easy way to prevent tank doors from being switched around. Use an engraving machine to do this properly and only once.
The same applies to tank rubbers and their sizes. If tank rubbers are not 100% the correct size, the likelihood of a leakage increases. Therefore ensure that if tank rubbers are removed, they are returned to the original tank. Rather wash them one by one at the tank itself. Do not simply throw all the rubbers into one tub to wash together. Alternatively, the tank number can be written on the outside of the rubber with a permanent marker if possible.
Sample taps and sight glass valves are items prone to leaks. They also have to be marked with the corresponding tank number to ensure that they are not misplaced. It is important to replace the rubbers regularly and usually it is easy to visually observe when they start to crack or show signs of ageing. It is better to err on the side of caution and replace rubbers if in doubt, as the cost of wine lost to leakage far outweighs the cost of these items.
It is extremely important to regularly clean sight glasses. Specially designed small brushes with long handle cords can be used to gently clean the entire glass on the inside. Sight glasses also tend to become brittle over time and can then crack easily. The consequence of cracked or dirty sight glasses is possible wine losses, inaccurate stock control and pumping of the incorrect volume of wine from one tank to another.
Pump maintenance
Every litre of wine in a cellar moves through a pump at one stage or another. If pumps are damaged or leak, it can impact negatively on wine quality. Consider the following guidelines:
- Assign a unique number or name to each pump in the cellar. This way it is much easier to identify pumps and report them to the workshop if faulty. It is also a good means to determine if there are certain pumps which regularly cause problems.
- If a pump leaks, record a video of where exactly the leakage is located. Also take a photo of the electrical fault message, which will not necessarily be possible to duplicate or read later. Accurate information about the problem assists the workshop in solving it more quickly.
- Bleeding of the pump must take place to ensure that it does not start dry. Running dry causes damage to the moving parts, both impellers and stators. A burnt-out stator can impart a burnt odour and taste to the wine. Mechanical seals can also be damaged if pumps run dry and then cause leakages. It is equally important that pumps do not run dry at the end of the pumping action. Especially when wine is drawn from a side tap and workers possibly walk away because they do not know how long it will take for the level to drop to under the side tap. Rather switch pumps off if you have to leave the machinery urgently. Or ensure that another person is always present to supervise pumping. Do not take any chances for the pump to run dry. The air (oxygen) sucked in when pumps run dry, must also definitely be avoided.
- Ensure that the pump is primed with water before initiating the pumping action. First pumping water through a line before the wine is pumped, has the following advantages:
- to identify possible leakages on the pump and the rest of the line;
- to ensure that the line is clean and free of blockages; and
- to ensure that the correct fixed lines are used.
Drains and trenches
Drains and trenches often receive less attention when it comes to cleaning than cellar floors. Ensure that these areas are also on a checklist to be thoroughly cleaned at least once per month. They are a possible breeding ground for spoilage micro-organisms and as such should be properly maintained.
Barrel maintenance
Just as it is important to place a fermentation cap on barrels during fermentation, it is also imperative to put fermentation caps on wines undergoing malolactic fermentation (MLF). Once MLF is completed, a permanent plug can be inserted.
Sometimes the area around the permanent plug or bung is not cleaned regularly, especially during topping up or sulphur additions in barrels. It then becomes a breeding ground for spoilage micro-organisms. Ensure that these areas are properly cleaned and form part of the work instructions. Use a light sulphur solution and brush for this cleaning action.
A wine barrel requiring cleaning on the area around the bung.
It is paramount to burn a sulphur dioxide (SO2) stick in empty barrels at least once monthly. If a barrel is to remain empty for more than three months, it is a good practice to rinse it properly. This helps to prevent the barrel from drying out totally and the water can also be used to smell and evaluate if the barrel is still healthy.
By observing and regularly checking adherence to these simple guidelines, many unnecessary mistakes in the cellar can be avoided.
For more information, contact Pieter Badenhorst at pieterb@fortheloveofwine.co.za.
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