Grading, Storage, and Packing in CTC Tea: Ensuring Consistent Quality

After CTC tea leaves pass through the drying stage, the work is far from over. What comes next – grading, storage, and packing – determines whether a batch of tea reaches buyers in peak condition or loses its value before it ever reaches a cup. These three post-manufacturing steps are where consistency is built, quality is locked in, and market value is secured. Understanding how each step works reveals a great deal about what makes a reliably good cup of tea possible at scale.

Why grading matters in CTC tea production 🔗

Once CTC tea exits the dryer, it exists as a mixed bulk – a combination of particles of different sizes, forms, and densities. Before tea reaches the teabag or caddy, it must be sorted into grades to ensure an even brew, since particles of different sizes infuse at different rates. Grading separates this bulk into distinct, uniform categories based on particle size and form, making the product commercially usable, traceable, and tradeable.

Grading serves several practical functions. It enables market segmentation – different buyers and regions have specific preferences for grade types. It supports consistent blending, since tea blenders need uniform raw material to replicate flavors reliably. And it directly affects pricing: well-graded, clean primary grades attract higher auction values than mixed or poorly sorted lots.

For many large CTC tea producers, 80-90% of factory output consists of small, broken primary grades suitable for tea bag blends, while the remaining 10-20% are secondary grades that trade at a discount. This makes accurate grading not just a quality step, but a commercial necessity.

CTC tea grades: what they are and how they differ 🔗

Because the CTC process breaks the leaf, there is no whole-leaf CTC tea – it is divided into broken-leaf, fannings, and dust grades. Each grade has distinct brewing characteristics and commercial applications.

Broken grades 🔗

These are the coarser particles produced during CTC processing. The primary broken grades include Broken Pekoe 1 (BP1) and Broken Pekoe 2 (BP2), as well as Broken Orange Pekoe (BOP). Broken Pekoe refers to medium-sized broken leaf, while BOP is slightly finer. These grades produce a full-bodied liquor with good strength and are widely used in loose-leaf blends.

Fannings 🔗

Fannings are smaller, grainy particles separated from the broken grades. In CTC manufacture, the main fannings grades are Pekoe Fannings 1 (PF1) and Pekoe Fannings 2 (PF2). PF grades are especially suited for tea bags, offering strong liquoring characteristics with bright infusions and a full-bodied cup that creams down well. Fannings brew quickly and are in high demand for the tea bag industry worldwide.

Dust grades 🔗

Dust is the finest grade in CTC production and includes Pekoe Dust (PD), Dust (D), and Churamani Dust (CD). Dust is the smallest grade, producing a quick-brewing, strong cup, generally used in catering-grade blends. While dust grades rank lowest in the size hierarchy, they remain commercially valuable for their rapid infusion and strong, thick liquor – qualities that remain popular in tea stalls across South Asia and Africa.

The grading process: equipment and stages 🔗

Sorting bulk CTC tea into clean, uniform grades is a mechanical process that requires specialized equipment and careful sequencing. Sorting of bulk tea must be done in three stages: cleaning of fibre, grading, and winnowing.

Stage 1 – Fibre extraction 🔗

The first step removes fibrous stalk material and flaky tea that would otherwise contaminate the final grade. PVC rollers are widely used for fibre removal; they are electrostatically charged through contact with a felt-like material, and this charge preferentially attracts fibre and flaky teas – which differ in moisture content and density from the rest of the bulk – allowing them to be pulled away cleanly.

A well-designed fibre extractor operates at slow roller speeds to ensure the tea itself remains untouched, preserving the natural bloom of the made tea without greying it. Bloom – the surface sheen of dried tea – is an important indicator of liquor character and can be lost if sorting is too aggressive or if the tea picks up moisture during the process.

Stage 2 – Grading by particle size 🔗

After fibre removal, the tea is fed through vibrating sifters fitted with graduated mesh screens. In CTC processing, after removal of stalks and fibre, the tea is fed to the Myddleton machine and then passed through Arnotts for final grading. The sorting machine has 8 to 10 trays through which the tea is sieved and segregated into different particle sizes. As tea passes through screens of progressively finer mesh, each grade drops into its own collection tray. This mechanical separation is precise and repeatable, essential for maintaining consistent grade specifications across batches.

Stage 3 – Winnowing 🔗

The final stage uses air to remove light, low-density material – including remaining dust and fine particles – from coarser grades. This step refines each grade further and improves the overall cleanliness and appearance of the sorted tea. The result is a set of clearly defined grades, each uniform in particle size and free of contaminating material.

Proper storage of made CTC tea 🔗

Graded tea must be stored carefully before it is packed or dispatched. Tea is highly hygroscopic – it readily absorbs moisture from the surrounding air – and even short periods of improper storage can degrade flavor, aroma, and shelf life.

Moisture content: the critical number 🔗

The ideal moisture content for stored CTC tea is around 3%, with a maximum permissible level of 6%. Beyond this threshold, quality deteriorates rapidly. When moisture content exceeds 8%, oxidation reactions accelerate, and exceeding 12% easily promotes mould growth. Keeping moisture within the 3-6% range is therefore not merely a quality preference – it is a commercial and safety baseline.

Once made tea picks up moisture, its liquoring quality is reduced and this cannot be recovered simply by reheating and driving the moisture out – the damage is irreversible. This makes prevention far more important than correction. The approach used in well-managed tea factories involves maintaining controlled humidity in storage areas using desiccant dehumidifiers, which supply dry air to storage bins and prevent moisture regain without the need for reheating the tea.

Temperature, light, and odour control 🔗

The ideal storage temperature for black tea is a steady ambient room temperature; light and moisture should still be avoided, and properly stored black tea can last two to three years. Storage areas should be located away from kitchens or areas with strong odours, as tea readily absorbs surrounding smells, which can permanently alter its aroma profile. Warehouses used for CTC tea must be kept clean, dry, well-ventilated, and free from direct sunlight.

Packing CTC tea: materials, methods, and standards 🔗

Packing is the final step before tea enters the supply chain. The packaging must protect the tea from the moment it leaves the factory floor until it reaches the end consumer – often through long supply chains spanning multiple climates and transit conditions.

Packaging materials used in CTC tea 🔗

The choice of packaging material directly determines how well the tea is protected. Several materials are commonly used, each with specific properties:

Aluminum foil pouches are the most effective option for moisture, light, and oxygen protection. Aluminum foil offers superior defense against moisture, light, and oxygen, is heat-resistant for teas exposed to high temperatures during transit, and can be recycled without losing its barrier properties. It is widely used for both loose CTC tea and tea bags.

Multi-layer laminate packaging combines materials – typically plastic film, aluminum, and paper – to deliver comprehensive barrier protection. Impermeable packaging such as foil-lined pouches or airtight tins helps retain the tea’s aroma and quality, with proper sealing being crucial to prevent exposure to air and humidity.

Paperboard cartons are used for retail packaging as an outer layer. They provide structural protection and serve as the primary branding surface, but must be combined with inner foil lining to provide adequate moisture and light barriers.

Plastic pouches made from polyethylene (PE) or polyethylene terephthalate (PET) offer good moisture resistance and are cost-effective for large-volume packing. However, research published in Food Packaging and Shelf Life found that PE and PET packaging showed lower adsorption of tea volatile compounds compared to polypropylene (PP), making them preferable choices for preserving aroma during storage.

Packing techniques 🔗

Vacuum packing removes air from the package before sealing, significantly reducing the rate of oxidation. This is particularly important for CTC grades destined for export, where tea may be in transit for weeks. Modified atmosphere packaging (MAP), which flushes pouches with nitrogen or inert gases, minimises oxygen exposure and slows oxidation, preserving the delicate flavors of tea for extended periods.

Sack packing is used for bulk export grades – typically multi-wall paper sacks or jute bags with inner polyethylene liners. For primary grades headed to auctions or large buyers, tea is packed in standard 40-60 kg paper sacks. Smaller consumer-facing formats use sealed foil pouches or cartons ranging from 100 g to 1 kg.

Labelling and compliance 🔗

Tea packaging must carry the product name, ingredients, net weight, manufacturer details, and expiration date on the primary display panel to meet food safety regulations. Certifications such as Fairtrade, organic, or food safety standards like BRCGS must also be clearly indicated where applicable. Proper labelling is not just a regulatory requirement – it supports traceability through the supply chain and builds consumer confidence.

The link between grading, storage, and final cup quality 🔗

These three steps – grading, storage, and packing – are not independent of each other. A tea that is graded precisely but stored in a humid warehouse will lose its liquoring quality before it ever reaches a buyer. Tea packed in poor-quality materials will absorb off-odours or pick up moisture during transit, regardless of how well it was graded. The quality of each tea depends on how it is cultivated, processed, handled, and stored – grading alone provides information about leaf size and appearance, not the final tasting outcome.

This is why leading tea-producing regions and estates invest as seriously in their sorting rooms, storage infrastructure, and packaging specifications as they do in the growing and manufacturing stages. India, which produces over 80% of its total tea output through the CTC method, has a strong commercial stake in maintaining these standards – both for the domestic market and for export to CIS countries, the Middle East, and the UK, where CTC teas dominate demand.

What do you think? Given that moisture control is so critical to preserving tea quality after manufacturing, how do you think small-scale tea producers without access to industrial dehumidifiers manage this challenge – and does that impact the quality of tea you drink? Also, with research showing that packaging materials can affect the aroma of tea over time, how much attention do you pay to the type of packaging when buying tea?

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