Plant cell structure under a microscope.

Scientific Studies of Tea

As a tea drinker, we rarely to stop to think about who is studying our favorite beverage and what are they learning. The complexities of the tea leaf itself and what drives those complexities are head spinning. So, it is truly exciting to find a translation in English of a qualitative review of who has been conducting scientific studies of tea and what they are learning about the plant and beverage.

White tea drying in China.

Published in the Frontiers of Plant Science, a group of scientists from the Hunan Agricultural University in Changsha China, did a review of the past decade of scientific studies of fresh tea leaves[1]. So, what did they find?

Who is Studying Tea?

It should not surprise anyone that most of studies of tea are coming out of China. They are largest and oldest manufacturer of tea, with the Chinese tea industry having an estimated total revenue of $99.8 billion in 2022. This accounts for approximately 1/3 of the total tea industry worldwide. The Chinese national government and local governments have designated the tea industry as a critical economic driver, making available government money for scientists to research tea. Interestingly over the past decade, while China logged over 600 studies, the United States actually managed to do 17 studies and worked in collaboration with the Chinese on enough of their studies to actually get mentioned by the authors. So, if you want to study tea in the US, head to the University of Florida, Rutgers University, Montana State University and the University of Georgia.

What is being Studied about Tea?

Both 2007 and 2017 seem to be watershed moments in the scientific study of tea. In 2007, the Human Metabolite Database was created. This freely available electronic database gives scientists detailed information about small molecule metabolites found in the human body. With access to this database, the study and identification of metabolites in tea as well as the effects of those metabolites on humans became the largest types of studies over the past decade. In 2017, the first full genome assembly of the tea plant was published which caused the expansion of studies into gene expression under stress caused by climate, soil and other changes. This category is expected to expand in the coming years as the publishing of studies, not surprisingly, decreased during the Covid pandemic.

Tea fields in Fuding China.

The authors project based on current trends in topics in scientific literature that we will see the publication of more studies in the future around the metabolic effect on the tea plant of cultivation treatments (watering schedules, fertilization, pesticide, and fungicide applications).  Other studies will include resilience of plant gene expression in the face of climate change, as these studies were starting to pick up in 2019 and again decreased dramatically because of the Covid pandemic.

As an avid tea drinker, these findings and projections bring me great joy and hope in the future for my favorite beverage.

[1] YiQuin Chin, YunFei Li, ChengWen Shen, and LiZheng Xiao, “Topics and trends in fresh tea (Camellia Sinensis) leaf research; A comprehensive bibliometric study”, Frontier of Plant Science, Volume 14, April 6, 2023.

Panamanian tea field with flag

Visiting a Panama Tea Plantation in Boquete

Panamanian tea is not a phrase you hear in the tea industry as I write this blog. However, if one entrepreneur has his way that may change in the future. During our travels, regardless of country, David and I are always looking for tea. We were shocked to find a tea tour offered in Western Panama. It’s available in a larger portfolio of tours alongside zip lining, coffee tours and general outdoor eco-adventures in Boquete. Even with the $30/person price tag, David and I had to find out if they really had true tea.

Panamanian Tea Tour – Boquete, Panama

Panama is better known worldwide for its Geisha or Gesha Coffee. As a side note to my tea drinkers, find this coffee – it tastes like tea! In fact, it was this association with tea that led to the tea plantation experiment. It’s also hardly a surprise that Gesha Coffee got rebranded as “Geisha” to improve marketing in Asia, especially Japan.

So, finding a steep mountainside of Camelia Sinensis Assamica in Boquete, growing at about 5,700 ft above sea level, was truly a delight.

Planting Tea in Panama

Boquete is a rural town about 9 hours by car outside of Panama City. The closest airport is about 45 minutes away in the town of David. It is high elevation, wet and sunny with plenty of fog, especially during the rainy season. This climate is similar to Sri Lanka or the Nilgiri region of India. It is home to large number of coffee farms, most of them owned and run by Americans and Europeans, and a few by Panamanians. Kotowa Tours (aka Boquete Tree Trek) is a Panamanian company, with a Panamanian owner, that has been around for over 100 years. While their properties are for outdoor recreation, like zip lines and hiking, they are growing coffee, chocolate and tea there as well.

Octavian and Hillary in the tea fields looking at a young tea plant.

Our tea tour began with a walk through the tea fields with Kotowa’s tea master in training, Octavian. Currently, plants cover less than 1 acre, but there is plenty of room to grow. The first of the tea plants went in 7 years ago and Octavian and his team of four other grounds keepers have been diligently collecting seeds and replanting every year progressing higher up the mountain. The plants are in beautiful shape, with just a few grasshoppers leaving an occasional bite mark on some of the leaves. The biggest “pests” are armadillos. They periodically burrow in to the ground near the roots killing a tea plant here and there. It was fitting to be climbing through the fields, only to be hit with incoming morning mountain fog and rain. The plants are truly in their perfect environment and their huge dark green leaves let you know it.

Harvesting and Manufacturing Tea

The plants are so happy that Octavian and his team are harvesting roughly every 25 days, year round. Now, that is not unheard of in Sri Lanka, India and parts of Africa. So we posed the questions about which months produced the better tasting harvest. It was not surprising to hear the December-March produce a sweeter tea since those are the “dry” months in Panama.

The entire harvest and processing is done by 5 people. They are plucking, rolling and shaping the leaves by hand. With only an acre, their largest given harvest is only about 250 kg (roughly 550 lbs) at a time. That will become roughly 50 kg of finished product, which is only 110 pounds of tea. This is very manageable for a team of 5 people. From harvest to finished product, it is only 4 days, with most of the time spent waiting on the tea to dry.

The processing of the tea will likely change as the tea plants expand and there is more to harvest and produce. Plucking will remain by hand as the mountainside is too steep for machines. We had a good laugh about finding tea manufacturing machines with instructions in English\Spanish and available replacement parts in the Western Hemisphere – there aren’t any.

Cupping Panamanian Tea

Dried and twisted green tea leaves in a glass container

Kotowa is currently trying to make white, green, oolong and black tea. With the help of an experienced tea master from Taiwan, Octavian is playing with withering times, baking times, and steaming techniques. We had a great time talking about his lessons learned and where he thinks he will continue to play and fine tune flavor.

Given his tea master is Taiwanese, it was no shocker that the teas where lighter and smoother, mimicking Taiwanese tea. The green tea has a real chance of being a unique flavor profile, as they are steaming the green, which is causing it to taste and smell like the corn meal on the outside of a Panamanian tamale (this is a sweet vegetal taste because the tamales are steamed in banana leaf wrappers).

We expect Octavian will have success in making uniquely Panamanian tea and wish him the best of luck!

Mandarin Orange Stuffed with Puerh

Whether it is mandarin oranges or tangerines, citrus fruits have played a large role in Chinese medicine for centuries. So it is no surprise to find a practice of stuffing tea into these dried fruits.


Mandarin Oranges, CC 2.0 by frans16611

Starting back around the Song Dynasty (900-1269CE), citrus fruit was used to treat sore throats, nausea, and congestion. The fruit would be eaten, then the rind would be dried and steeped in boiling water or tea. There is currently no known documentation around when tea, and specifically puerh, began being stuffed into dried citrus fruit. However given that the Song Dynasty continued the rise of tea as an everyday beverage for all Chinese people, that began during the previous dynasty, it is not a far stretch to speculate that tea may have been stuffed into citrus during this period. Much of the citrus fruit in China is also grown in the same regions as the tea – Yunnan, Guangdong and Fujian.

How Mandarin Oranges are Stuffed with Puerh

As you can imagine it is a rather labor intensive to stuff tea into an empty citrus rind. To start, a small hole is carved into the top of the fruit and then needle nose plyers are used to reach into the fruit and pull out all the citrus meat and thin the rind. Then, while the rind is still soft, tea is dropped into the rind, the fruit is then shook and the tea gently pressed down until the rind is full. The cap is put back on and the fruit is put out to sun dry or into a dryer at less than 200°F to dry the rind. The tea has already been fully dried. So, the thing to note about this production process, the goal is to not crack the rind while pulling apart the fruit or stuffing in the tea. The amount of money a tea manufacturer can get for these creations is judged on how little damage there is to the rind.

Since this tea is thought of more as medicine in China, its flavor profile is rarely considered. However, those of us approaching it strictly for its flavor will find a similarity to Earl Grey. It is earthier, because of the aging of the puerh and citrus rind, but still has a citrus finish. One of our favorites is a 2007 Mandarin Orange stuffed with a shu puerh from Yunnan.

How to Brew a Mandarin Orange Stuffed with Puerh

Western Style Preparation: Break off roughly 3 grams (about a teaspoon) of puerh and orange rind and add to infuser. Steep 2-3 minutes with boiling water. Re-steep a second time for 3-4 minutes. Try additional infusions at 5 minutes each while you are still happy with the taste & strength of infusion. Store any unused mandarin orange puerh in an open zip-lock bag away from any strong aromas (a home office is a great location). This tea can continue to age for years to come if desired.

Asian Style Preparation: Using a medium size Gaiwan infuse 2/3 to one whole mandarin orange ball with boiling water. Perform a quick wash by pouring boiling water over the mandarin orange puerh ball before immediately discarding. Then steep 20 seconds and pour off into a cup or small pitcher and enjoy. Steep a second time for about 15 seconds and enjoy. Steep 6-10 more times adding slightly to the infusion time subsequent infusion.

History of Mulling Spices

Across a multitude of years and cultures, the consumption of mulled wine is long synonymous with winter, evocative of cold nights, holiday gatherings, and good cheer. Brewed by steeping a variety of herbs and spices into (most often) a red wine base, this festive beverage has a long and storied history that is well worth looking into.

crockpot to make it in

The making of mulled wine dates back to antiquity, first entering written records in the 2nd century BCE. The ancient Romans were frequent consumers of various mulled concoctions, with mentions by such writers as Pliny the Elder and Apicius. In addition to being delicious, spiced wine was considered medicinally beneficial, as its purported “hot, dry” properties were seen as an effective remedy against imbalances of the humours. Over the centuries, the spread of the Roman empire and increase of global trade resulted in spiced wine’s popularity throughout much of mainland Europe and into Asia. One commonly-seen variant was known as hippocras, which in addition to either red or white wine, featured spices such as cloves, cinnamon, ginger, long pepper, and grains of paradise. It was known to have been served both hot and at room temperature – while overnight, room-temperature steeping of the spices was one of the more frequent methods to make it, heating the mixture ensured that added sweeteners dissolved into the liquid properly.

As time went on, hippocras and beverages of its kind continued to spread and shift according to regional taste and preference. Sugar or honey was often added, especially in hot preparations, to balance astringency. In the British Isles, hot mulled wine mixtures were a common way to stave off the winter’s bitter chill, eventually giving rise to such drinks as wassail and Smoking Bishop (one of several members of the “ecclesiastical” family of mulled wines, including the claret-based Smoking Archbishop and the burgundy-based Smoking Pope).

Meanwhile, in Germany and the Alsace, glühwein emerged as another popular winter beverage, and today remains a staple of many regional Christmas Markets. Nordic countries favor a similar preparation called glögg, gløgg, or glöggi, which, in addition to wine and spices, may also feature add-ins such as juice, syrup, or harder spirits. Across the ocean, Brazilians enjoy vinho quente during their winter months, especially mid-June. The list goes on! All over the world, mulled wine is enjoyed as a delicious and fortifying way to warm up from the cold. The variations in spices and additives are virtually endless. We here at Dominion Tea love a cinnamon and clove-forward blend, with ginger, allspice, and lemon peel for extra flavor. What’s your favorite mixture?

By: Jen Coate

History of the Hot Toddy

Autumn will be here soon, and we at Dominion Tea can’t help but feel excited! Crisp weather, colorful leaves – and, of course, the return of some of our favorite cozy flavors. And while so many of the seasonal beverages are tasty, we wanted to shine a special spotlight on one delicious remedy, the unsung hero of cold and flu season: the hot toddy

Hot Toddy in Cup with Jar of Honey, Cinnamon Stick, Shot Glass

If you haven’t tried a hot toddy when you’re under the weather, you’re missing out. This historic drink has a long reputation for soothing sore throats and stuffy heads. However, what exactly goes into a hot toddy is a matter of debate. Some start with black or herbal tea, while others just use hot water. Some call for sugar, some honey. Some may use whiskey, some brandy, some no alcohol at all… the list goes on. But all variations aside, the essence of the drink remains the same: a tea or water base flavored with sweetener, citrus, and warming spices, often (but not always) bolstered with a shot of alcohol. 

So when and where can we find the true origins of the fabled hot toddy? One popular theory holds that it may have begun its life in British-occupied India during the 18th century, when trade brought the traditional palm wine known as tadi (or toddy) to European attention. This drink was often mixed with sugar and warming spices, evolving over time into the hot toddy we know today. 

Other theories speculate that the hot toddy was first invented in Scotland. Named for Edinburgh’s Tod’s Well, the city’s primary water source, this toddy began as a bracing mixture of Scotch whisky with hot water and spices to fend off the cold of northern winters. Still others claim that the drink may be credited to 19th century Irish physician Robert Bentley Todd, who was said to have often prescribed his patients a hot drink mixture consisting of water, sugar, cinnamon, and brandy. 

Regardless of where it came from, the hot toddy still retains a respected place among our favorite seasonal drinks. Its endless variations are the perfect way to mix and match flavors just the way you like. We favor a cozy and soothing blend of caffeine-free honeybush, warming spices, and lemon peel in our toddy base blend – perfect with a dash of honey and whiskey for those blustery nights. What’s your favorite way to enjoy a hot toddy? 

By: Jen Coate