Importance of Factory Hygiene in Orthodox Tea Manufacture

Factory hygiene is not just a housekeeping matter in orthodox tea manufacture – it is a direct determinant of tea quality and safety. From the moment green leaf arrives at the factory to the point the finished tea is packed, every surface, machine, and floor it touches is a potential source of contamination. Bacteria, moulds, and physical foreign matter can silently undermine the flavour, aroma, and safety of tea if hygiene is not rigorously maintained at every stage of production.

Why hygiene is so critical in tea manufacture 🔗

Orthodox tea manufacture involves a series of time-sensitive biological processes – withering, rolling, fermentation, and drying – each creating conditions that can either preserve quality or allow contamination to take hold. According to Clean India Journal, the long interval between plucking and processing, followed by an oxidation period of around 2.5 hours for orthodox manufacture, creates the possibility of considerable bacterial build-up. This window is long enough for microbial populations to grow substantially if the production environment is not kept clean.

The possible sources of contamination in a tea factory include the oxidised leaf, the factory floor, and the surrounding air. What makes this particularly challenging is that contamination risks change character as tea moves through the factory – from wet-process zones like the rolling and fermentation rooms, where washing is feasible, to the drying and sorting areas, where moisture must be carefully controlled.

Contamination risks at each stage of manufacture 🔗

Rolling room: the first major hygiene hotspot 🔗

The rolling stage, while essential for initiating fermentation by breaking open leaf cells, also creates significant hygiene risks. During rolling, leaf juice is expressed and drips down to the floor along with leaf fragments, which can become a source of bacterial growth. This juice can also adhere to roller caps, roller doors, and ball breakers. If these surfaces are not cleaned at the end of each day’s manufacture, the bacterial infection is carried over to the next batch, compromising its quality before processing even begins.

The floor of the rolling room is a particularly dangerous source of infection. The expressed juice should be washed away immediately, and the floor should ideally have a steep slope from the rear to the front of the rollers to direct juice towards a side drain. The use of all-metal leaf trolleys is preferred because they are easier to clean thoroughly and reduce the surfaces on which bacteria can proliferate.

Green leaf sifters are another common contamination point. They can infect leaf with bacteria very easily, and a high-pressure hose is the recommended tool for cleaning them. Even with daily cleaning protocols, infections can develop on sifters mid-manufacture, which means vigilance throughout the day is necessary – not just at the end of it.

Fermentation tables and dhool: managing the oxidation environment 🔗

The fermentation stage, where rolled leaf (dhool) is spread out on tables or trays to undergo oxidation, requires especially careful hygiene management. Ideal fermentation conditions include a dhool temperature below 30°C, moisture around 55%, a pH of 4.5 to 5.0, and relative humidity above 90%. These warm, moist conditions are also ideal for microbial growth, which makes the cleanliness of fermentation surfaces critical.

Fermentation tables must be cleaned with hot water after every day’s manufacture. The wet processing area, including rollers and the fermenting area, must be cleaned well after every day’s manufacture – ideally with hot water to kill bacteria. Residual leaf particles left on tables provide a food substrate for bacteria, which can then contaminate the next batch of dhool placed on those same surfaces.

Drying and sorting rooms: a different hygiene challenge 🔗

Once tea enters the drying stage, the hygiene management approach must shift. Wet washing is no longer suitable because moisture in these areas can itself trigger new microbial problems. The factory floor up to the stage of fermentation can be kept clean by washing, but the same approach cannot be followed in the drying room and beyond. If the drying and sorting rooms are not managed properly, or if the atmosphere is warm and dusty, a different group of moulds starts to grow. These moulds adversely affect tea quality and are harder to eliminate once established.

Dry cleaning of the drying room, heater room, and packing room using brooms and vacuum cleaners is the recommended approach for these areas. This prevents the introduction of moisture into zones where it can cause more harm than good. Dust accumulation, in particular, must be actively controlled – fluff and fine tea particles settling on surfaces or equipment can harbour moulds and provide nutrients for microbial growth.

The role of dust and fluff accumulation 🔗

One of the less immediately obvious hygiene concerns in a tea factory is the steady accumulation of fine dust, tea fluff, and fibre particles. These settle on machinery, walls, ceilings, and floors throughout the factory. Beyond being a physical contaminant, a warm and dusty atmosphere, combined with moisture and the organic substrate present in made tea, creates ideal conditions for mould growth. These moulds can make their way into the finished product, adversely affecting its quality, shelf life, and safety.

Preventing this requires a consistent routine. High-pressure cleaning systems are widely used in modern tea factories to address this. High-pressure water jets can reach the intricate parts of rolling machines, removing stuck particles and residues without damaging the equipment, and are effective in dislodging tea particles, dust, and leaf debris from machine surfaces. For areas that cannot tolerate water, regular dry vacuum cleaning is essential to remove the same accumulations without introducing moisture.

Microbial hazards: what is actually at risk 🔗

Understanding the specific microbial threats in a tea factory makes the case for hygiene even more concrete. Food safety analysis of tea processing identifies several bacteria of concern. Tea leaves are handled by multiple operators during withering, rolling, fermentation, sifting, and packing, which increases the risk of E. coli and Staphylococcus aureus contamination due to poor personal hygiene and improper cleaning of utensils and surfaces.

Fortunately, the drying stage acts as a natural kill step for most bacteria. There are no reported microbiological food safety hazards relating to made tea. However, risks of contamination exist at the processing stages due to environmental factors and personnel hygiene, and these are largely arrested at the drying process. This makes pre-drying hygiene all the more important – contamination introduced in the rolling or fermentation room has until the drier to do its damage, and in that window, it can significantly degrade the quality of the batch.

Moulds are an even more persistent concern. During firing, most bacteria are destroyed, but moulds have been known to persist even after drying. This means that mould contamination that enters through dusty, poorly maintained drying or sorting rooms may survive into the finished product.

Good manufacturing practices and hygiene standards 🔗

Maintaining effective hygiene in a tea factory requires more than reactive cleaning – it demands a systematic framework. The U.S. FDA’s HACCP guidelines specify that all procedures for cleaning and sanitation of equipment and the facility should be written and followed, and a master sanitation schedule should be in place. In the context of tea manufacture, this means documented daily cleaning routines for the rolling room, fermentation area, and all associated machinery, with clearly assigned responsibilities.

Food safety best practices for tea production confirm that every aspect of the production facility, from processing floors to equipment, must adhere to rigorous cleaning and sanitisation protocols, and that staff must be thoroughly trained in personal hygiene practices including regular handwashing, appropriate attire, and use of protective gear. Worker hygiene is thus inseparable from factory hygiene – dirty hands and improper clothing are contamination vectors just like an unclean rolling room floor.

In India, tea factories are also subject to regulatory oversight. Teas marketed in India must pass Food Safety and Standards Authority of India (FSSAI) specifications, which include black tea quality parameters along with limits on pesticide residues and heavy metals. Meeting these standards requires that hygiene be maintained consistently, not just during an inspection.

Practical hygiene protocols for tea factory managers 🔗

Translating hygiene principles into daily factory operations involves a set of practical, non-negotiable routines. Based on the technical guidance available for tea factories, the following measures are central to maintaining a hygienic production environment:

• Rolling room floors should be washed immediately after manufacture using high-pressure water jets, and floors should be sloped to allow juice and wash water to drain freely to side drains.
• Rolling machinery including roller caps, doors, and ball breakers should be cleaned daily with hot water to prevent juice and leaf fragment residue from building up and becoming a bacterial source the following day.
• Green leaf sifters should be cleaned with a high-pressure hose at the end of every day, as they are particularly prone to mid-shift bacterial buildup.
• Fermentation tables and trays should be washed with hot water after every batch, removing all residual dhool and organic matter that could feed bacterial growth in the next fermentation cycle.
• Drying, heater, and packing rooms should be dry-cleaned using brooms and vacuum cleaners to prevent dust, fluff, and fine leaf particle accumulation without introducing moisture into these sensitive environments.
• All-metal leaf trolleys are preferred over other materials as they are easier to clean thoroughly and support lower bacterial growth.

After cleaning, equipment and surfaces should be allowed to air dry or dried manually, particularly in fermentation or drying rooms where moisture levels must be controlled, and equipment should be inspected to ensure no residues remain before the next batch of tea production.

Hygiene as a quality investment 🔗

In orthodox tea manufacture, quality is built at every stage – from the way green leaf is plucked to how finished tea is packed. But quality can also be lost at every stage, and factory hygiene is one of the most consistent points of vulnerability. A clean rolling room floor, well-maintained fermentation tables, and dust-free drying rooms are not just regulatory requirements – they are direct contributors to the flavour clarity, aroma, and safety of the finished tea that reaches the consumer. Achieving international certifications like HACCP or ISO 22000 formalises this commitment, but the daily discipline of factory hygiene is what actually makes it real.

What do you think? Given that bacterial contamination can build up significantly during the rolling and fermentation stages, how should factory managers balance the pressure of continuous production with the need for thorough mid-shift cleaning? And with moulds capable of surviving even after the drying stage, what additional safeguards could tea factories adopt to protect the quality of their finished product?

References

1. https://cleanindiajournal.com/maintaining-quality-hygiene-in-tea-manufacturing/
2. https://riggerspumps.com/tea-factory-equipment-and-how-high-pressure-cleaning-is-accomplished/
3. http://iso22000resourcecenter.blogspot.com/2016/08/tea-safety-what-are-key-areas-of-food_21.html
4. https://www.fda.gov/food/hazard-analysis-critical-control-point-haccp/haccp-principles-application-guidelines
5. https://www.japanesegreenteain.com/blogs/green-tea-and-health/ensuring-food-safety-in-tea-production-best-practices