Buying black or green tea in bulk is only half the job. Once the leaf goes into a bag, a second set of quality variables takes over — cut size, moisture, aroma loss, dust and how the tea was stored before packing. A retail chain, an online seller or a wholesaler building a private label range does not need to become a tea taster, but it helps to know which of these factors decide whether the finished bag still delivers a good cup a year later.
Leaf grade and cut: what actually fits in a bag
Tea grades sort leaf by size and wholeness rather than by taste. Whole and large broken leaves unfurl slowly and suit a pot or infuser; the smaller fannings and dust grades expose far more surface area and give a full-coloured cup in three minutes. That is why the bagged segment worldwide leans towards fannings, broken grades and CTC (crush-tear-curl) black teas.
For a buyer the practical consequence is that the cut must match the bag. A string-and-tag bag doses evenly with small, uniform particles, while large leaf bridges in the hopper, gives erratic fill weights and may sit half-wetted in a small bag. Ask what cut the co-packer's line runs well and specify the leaf accordingly.
Moisture: the number that decides shelf life
Finished tea is a dry product, and its stability rests on staying dry. Leaf that arrives too damp loses aroma quickly, sticks together in the feed system and, in a warm store, invites mould; leaf that has been over-dried is brittle, breaks into excessive fines and tastes flat. Reputable suppliers state a moisture value on the lot; buyers should ask for it and check that the packing site keeps bulk material sealed between goods-in and bagging.
Green tea sits at the more sensitive end of this scale. Because it is unoxidised, its bright, vegetal character depends on volatile compounds and on the leaf not picking up moisture or oxygen, so it usually loses freshness sooner than a black tea kept in the same warehouse.
Aroma retention from hopper to shelf
Every stage between the sack and the sealed carton costs a little aroma. Open trays, long dwell times in the hopper, warm rooms and strong neighbouring smells all take their share, and tea absorbs surrounding odours readily. Lines that keep the exposed run short and envelope each bag straight after filling preserve more of what the buyer paid for. An individually wrapped bag limits oxygen and humidity exchange for each serving, so the last bag in the box tastes like the first; for a premium black or a delicate green, the envelope is part of the quality specification, not a cosmetic extra.
Dust control on the line
Fine tea dust is inevitable when small-cut leaf is handled, but a well-run line manages it rather than lives with it. Excess fines pass through the bag paper, cloud the infusion, coat the weighing system and cause fill weights to drift. Green teas, being more brittle, generate more fines than a robust black CTC and need gentler feeding. Signs of a controlled process include:
- sieving or de-dusting of incoming leaf before it reaches the hopper;
- cleaning of the feed and weighing system between lots and between tea types;
- regular fill-weight checks against the target gram weight;
- separate black and green runs so one tea does not carry the character of the last.
Storage before bagging: the quiet risk
Much of the quality lost in a bagged tea is lost before the machine ever runs. Bulk sacks left open, on the floor, next to spices or cleaning products, or in a warm corner of the warehouse degrade quietly. Good practice is simple: keep tea sealed, off the floor, cool and away from odour sources, work opened material in rotation and reseal partial sacks at once. A buyer visiting a packing site learns a lot just from where the tea is standing.
Black versus green: a handling comparison
| Factor |
Black tea (CTC / broken) |
Green tea |
| Robustness to heat and air |
Relatively tolerant |
More sensitive; freshness fades sooner |
| Typical bag cut |
Fannings, CTC, broken grades |
Fine cut or broken grades, brittle |
| Dust generation |
Moderate |
Higher; needs gentler feeding |
| Priority controls |
Moisture, fill weight |
Short exposure, envelope, oxygen and light |
| Sensitivity to neighbouring odours |
High |
Very high |
Questions to put to a co-packer
Before committing a black or green tea to a contract bagging partner, a buyer should get clear answers on:
- Which bag format is available (string and tag, enveloped or not) and what gram range the line runs?
- What throughput the machine achieves and how that translates into scheduling?
- How the site checks moisture and controls fines on incoming leaf?
- What food safety and quality management system is in place, and whether herbal, fruit or customer-supplied blends can run alongside black and green?
- How minimum order quantity, lead time and private label design support are confirmed?
Labelling rules differ by market, so check the specifics with the competent authority or a regulatory adviser for the country where the tea will be sold.
At TeraVella in Antalya, Türkiye, our string-and-tag line bags roughly 1,000 enveloped bags per hour at an adjustable fill weight (for example 1.5–3 g), under ISO 9001 and ISO 22000 with HACCP principles applied, for black, green, herbal and fruit teas or a customer's own blend, with private label terms confirmed at quotation.
