Partha Sarathy Chatterjee leads sourcing management and quality control at Newby Teas, overseeing the selection, preservation and evaluation of teas from some of the world’s most renowned tea-growing regions. With more than three decades of experience in tea planting, tasting and blending, he plays a key role in maintaining the exceptional standards and consistency behind every Newby blend.

Can you tell us about your journey into tea and how you became a sourcing expert?

My journey into tea began in Assam, India, a region renowned for its rich, malty teas. Growing up in Digboi, surrounded by tea estates, I was introduced to tea from an early age through visits to plantations with my uncle, who was a tea planter. After graduating, I joined Duncan Brothers as an Assistant Manager and tea planter, later working with Goodricke for ten years. During this time, I learnt every stage of tea production, from cultivation to manufacturing.

I later moved into full-time tea tasting and blending with Hindustan Unilever, where I refined my tasting skills by evaluating hundreds of cups each day. Since 2004, my work has focused on tea tasting, blending and quality control. The process of selecting exceptional teas and creating blends tailored to consumer preferences remains both challenging and rewarding.

What does a typical tea sourcing season look like? 

At Newby Teas, our sourcing focuses primarily on the second flush season, which is widely regarded as the finest harvest of the year. First flush teas, harvested in March and April after winter dormancy, are delicate, floral and lightly astringent, but they have a shorter shelf life.

Second flush teas, harvested between May and July, are fuller-bodied, richer and more complex, with deeper colour and a lingering aftertaste. For decades, second flush teas have been considered the benchmark for quality. Newby sources its annual requirement during this period and preserves the teas in climate-controlled, vacuum-sealed conditions in Kolkata to protect them from moisture, light and odours.

How do you identify an exceptional tea estate?

Experience plays a major role. Over more than two decades in sourcing and tasting, I have built strong knowledge of the estates that consistently produce exceptional teas. At Newby, we also rely on a historical database spanning more than 20 years.

Beyond flavour and quality, we consider manufacturing standards and certifications such as HACCP, ISO, Rainforest Alliance and Ethical Tea Partnership. Ethical sourcing and sustainable practices are just as important as the quality of the cup.

What factors influence the character of a tea?

Altitude, climate and soil all shape the final character of a tea. High-altitude teas such as Darjeeling are known for their floral and muscatel notes, while lower-altitude regions like Assam produce bold, malty teas.

Climate also has a strong influence. Moderate temperatures and balanced sunlight encourage better flavour development, while excessive rain or cold conditions can affect quality. Mineral-rich acidic soil contributes to complexity and structure in the cup.

At Newby, plucking standards are equally important. The top two leaves and a bud contain the lowest fluoride levels, so careful plucking is essential. We also test our teas through Eurofins to ensure compliance with EU pesticide standards.

How do you maintain relationships with tea producers?

We work closely with producers and organisations such as the Calcutta Tea Traders Association and the Ethical Tea Partnership. Because our sourcing focuses on a relatively small group of exceptional estates, we are able to maintain close and personal relationships with suppliers in Assam, Darjeeling and beyond. We also remain in regular contact with suppliers in Sri Lanka, China and Japan to stay updated on manufacturing practices and certifications.

How do you ensure consistency in tea flavour year after year?

Consistency is one of the greatest challenges in tea blending. At Newby, every blend has a preserved master sample used as a benchmark for future production. Every tea is carefully scored for body, aroma, briskness, appearance and overall character.

There are several stages of tasting: individual lots are evaluated before purchase, teas are re-tested after arrival at our preservation facility, hand blends are compared against master samples, and the finished production blend is tasted again before release. This layered approach ensures consistency from year to year.

What separates a good tea from a truly exceptional one?

A good tea satisfies you, while an exceptional tea leaves a lasting impression. Exceptional teas reveal multiple evolving layers of flavour, complexity and aroma, with a memorable finish.

The leaf appearance and infusion are also important. Exceptional teas stand out through their origin, craftsmanship and clarity in the cup. Ultimately, they create a genuine sense of discovery and a memorable experience.

What is it like working alongside Newby's Chairman Nirmal Sethia?

Mr Nirmal Sethia began his journey as a tea taster at just 14 years old and brings decades of experience to Newby. Even today, he tastes teas regularly and remains deeply involved in the creation of every blend.

Working with him is both inspiring and educational. For every new blend, our team prepares multiple options which are carefully evaluated and refined together. Small adjustments may be made repeatedly over several months until the desired character is achieved. After eight years at Newby, I still learn something new from every interaction with him.

Can you share a memorable tea blending experience?

One memorable project was creating a bespoke blend for a luxury date brands in the Middle East. The brief was for a black tea with warm, sweet spice notes that could be enjoyed without milk.

After several trials using clove, star anise, cinnamon and apple pieces, the blend still felt incomplete. Mr Sethia suggested adding a touch of natural vanilla flavour, which balanced the spices perfectly and brought harmony to the cup. The final blend matched the brief exactly and was very well received.

What are the key considerations when creating an English Breakfast tea blend?

An English Breakfast tea should be malty, balanced and full-bodied, with enough brightness to be enjoyed both with and without milk.

Achieving this requires carefully balancing teas from different origins. Assam provides body and maltiness, Ceylon adds spice and structure, while Kenyan teas contribute colour and brightness. The aim is to create a rich amber cup with depth, balance and versatility.

Why is timing so critical during tea harvest season?

First flush teas are delicate and floral but are best enjoyed fresh due to their shorter shelf life. Second flush teas are bolder, richer and more stable over time.

Because Newby focuses on sourcing during peak second flush, close attention must be paid to weather conditions throughout the season. Rainfall, temperature and humidity all affect when the tea bushes begin producing the finest leaves.

How do changing climate conditions affect tea sourcing?

Tea production is highly dependent on climate. Moderate temperatures, humidity and rainfall are essential for healthy bud growth, while extreme weather can damage quality.

At Newby, we closely monitor climate patterns from late winter onwards to predict the timing and quality of the second flush harvest. This allows us to source teas at their peak.

Do you have a personal favourite tea?

My personal favourite is Newby Earl Grey. A great Earl Grey should have a balanced citrus note, a smooth body and a clean, lingering finish.

Many Earl Grey teas can taste overly perfumed or artificial, but Newby Earl Grey stands out for its natural bergamot character and elegant aftertaste. Its balance and smoothness are what I appreciate most.

What advice would you give someone looking to better understand fine tea?

When tasting tea, focus first on the aroma. Smell the tea before sipping and pay attention to the top notes, body and finish.

A fine tea should have harmony between aroma and liquor, with complexity that develops throughout the tasting experience.

What still excites you about tea after all these years?

Tea continues to surprise me. At Newby, we work with more than 145 varieties, from black and green teas to oolongs and herbal blends.

Every year we discover rare and exceptional teas from China, Japan and Taiwan, and there is always something new to learn. That constant discovery and pursuit of excellence is what keeps tea endlessly exciting for me.