South Africa Wine Technical Yearbook 2025

Flotation machines • Gelatin tends to become rock-hard when left standing for too long. Ensure, therefore, that the whole dosing unit of the flotation machine is rinsed with warm water so no gelatin is left behind in the unit. • Open all taps and also make sure that the front filter is removed and cleaned well. Red wine fermentation tanks • As with the canvas tubes in white wine separators, the tubes coming in from the fixed lines must be removed and cleaned inside and out, after which these must be stored in a safe place. • The pump-over sprayers should also be detached and properly cleaned. • Ensure that all taps and doors are open and that no water remains in any part of the system. Mobile mash pumps and screw conveyors • Ensure that all the grape skins have passed through the conveyors and none remain in nooks and crannies. • Open the drainage valves or plugs, and in the case of plugs, store them in a safe place for the next season. • Store the mobile mash pumps in a place where they will stay clean and dry until the next season. Wine presses • After the last cycle of the season, the press must be rinsed out properly to ensure that all grape skins have been removed. • Remove the juice channels if possible and wash off the tartrate crystals with a caustic potash solution, followed by a diluted acid solution and clean water. • The press drum can also be rinsed with a low concentration of caustic potash and acid to remove tartrate crystals and colour, in the case of red wine. • Rinse thoroughly with water to ensure that no chemical residue remains on the membrane. • Leave all taps in an open position and store bladder presses with doors turned to the bottom. • Also ensure that the juice collection tray under the press is clean and dry, so too any pumps and fixed pipelines attached thereto. Last but not least – safety • With all actions in the cellar, remember to always put safety first. • Use and wear the correct PPE, especially when handling chemicals. • Ensure that the power source of moving machines is securely locked out/disabled before working on or in the machine, press or tank. 

• Next, neutralise the alkali with a 0.5% acid solution. Organic acids like citric acid work well, but can also serve as carbon sources for certain microbes. In this regard, inorganic acids like nitric or phosphoric acid would be preferable. Both have a good effect on stainless steel. • Rinse thoroughly with clean water and drain completely so that all the lines can be stored dry. Stagnant water is a breeding ground for disaster. • The same applies to the cooling water. Drain it completely from the system, otherwise it will stand still for nine months and become rotten. Mash pump • Make sure that the bottom drainage taps of the mash pump are open. • If there is a plug, the best practice is to attach the plug to a chain so it doesn’t get lost. Otherwise, ensure that the plug is stored in a safe place where it is easily accessible for the next season. • If possible, remove the stator of the pump and inspect it for wear and tear. Grape pipelines Many cellars have pipelines that can transport to various parts of the pressing cellar. Many of these lines are not necessarily used regularly. • At the end of the season, ensure that all lines and routes are rinsed to make sure that no grapes or juice remain behind in the system. The rinsing of grape pipelines usually requires large amounts of water, but it is essential to rinse thoroughly to prevent the growth of unwanted micro-organisms in the cellar. The used water could be repurposed for irrigation in the cellar’s gardens. • As with the mash pump and mash cooler, it is essential to ensure that the pipelines are fully drained and stored in a dry condition. White wine separators • Make sure that all taps and doors are fully open. The doors tend to occasionally swing shut. • Remove all grape skins from under the conveyors, especially in the far back corner. Any grapes left behind there can become a breeding ground for unwanted organisms. Use a bright light to inspect, as the separators tend to be quite dark on the inside. • If canvas tubes are used to connect the fixed grape line to the separators, it is a good practice to remove such tubes, clean them thoroughly inside and out, and store away safely for the next season. • If the separators are cooled, it is also a good practice to drain cooling water from the equipment thoroughly.

For more information, contact Pieter Badenhorst at pieterb@fortheloveofwine.co.za. Reference https://wineland.co.za/post-harvest-cleaning-of-equipment/

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TECHNICAL YEARBOOK 2025