Learning more about coffee and tea

iced coffeeLike most of you, coffee and tea are part of our daily routines, and we pay just as much attention to these drinks as we do to the food on our plate. Lucky for us, we’re living in an age of easily accessible, high-quality coffee and tea. But we’re not just looking at the best flavor. We’re also looking at the farming, drying, roasting, and brewing processes to ensure tasty toxin-free beverages. Thanks to our friend Dave Asprey, the brains behind Bulletproof, we’ve learned so much about sourcing the cleanest coffee possible.

Our coffee comes to us from Intelligentsia Coffee in Chicago. Yes, we know there are many local roasters in the Bay Area, but we have chosen Intelligentsia for a few very specific reasons: First, they take the utmost care to ensure that their coffee beans never grow dangerous molds by collaborating with their coffee farmers through a Direct Trade relationship. Second, they procure beans seasonally, and this step keeps us as engaged with the coffee growing process as we are with our produce. Third, we love the idea of bringing a new roaster to the area and being their home in the Bay!

We’re partnering with Samovar in San Francisco to supply tea to our cafe. We love the exacting and passionate ways that Samovar procures and brews their teas in their cafe, and we are honored to be able to serve them at Mission: Heirloom. Samovar sources unique, organic teas from all over the world, which gives us an opportunity to taste the skilled art of this ancient drink. Like Intelligentsia, they are committed to sustainable and safe growing practices.


Purchase the highest quality you can afford: There are many high-quality coffee roasters and tea suppliers online and and in major cities these days. Purchasing high-quality coffee is especially important for ensuring a safe, mold-free product. Find a roastery you like and then ask them about their quality control process. Listen for key words like “wet-hulled,” “wet processed,” “raised drying beds,” and “single estate,” — purchase those beans. Organic whole leaf tea is likewise your best best for quality and flavor.

Optimize your water: The water that comes out of your tap might not be the optimal brewing choice. The proportion of minerals in your water will alter the taste of the final drink. If you find your coffee and tea tasting flat or tart, your water likely needs a boost in minerals. If your drink simply doesn’t have full flavor, you may have so many minerals in your water that they are preventing full flavor extraction.

Monitor the brew: Both coffee and tea can change in flavor dramatically depending on how they are brewed. Pay attention to the directions on the tea package for optimal steeping times and proper water temperature. Coffee beans should be ground right before brewing to ensure freshness. Choose brewing methods that fully remove the finished coffee from the spent grounds to produce the best tasting drink.

Practice, taste, and practice again: Brewing great coffee and tea takes practice and familiarity with the product. You’ll find that you also develop preference for different flavors and aromas. Hone in on that taste and tweak your brews to suit your own personal palate.



Whether its a hot cup of coffee first thing in the morning or a refreshing glass of iced tea at lunch, most of us drink caffeinated beverages at least once a day. In fact, caffeine is the most widely consumed behavior-modifying chemical in the world. When consumed in moderation, it is likely not terribly harmful — caffeine stimulates the central nervous system, relieves drowsiness and fatigue, quickens reaction times, increases our muscles’ energy production, and can improve mood and mental performance. Of course, too much caffeine has its own share of problems, namely increased heart rate, nervousness, and insomnia.

Coffee and tea are the most common vehicles for caffeine (well, those and chocolate). Coffee beans are around 1 to 2 percent caffeine and tea is 2 to 3 percent caffeine; however, brewed coffee typically contains a greater amount of extracted coffee beans and therefore caffeine. Both coffee and tea are excellent sources for antioxidants and other beneficial phenolic compounds like catechins (in tea) and quinines (in coffee). Of course, they’re both pleasurable to drink — we can’t imagine mornings without our regular cup of coffee or tea.

The History and Production of Tea

The first teas were prepared around 2000 years ago in Southwest China, but the leaves were likely chewed as a stimulant for long before that date. Around the third century, tea leaves were first boiled and then dried for later use. The introduction of dry heat into the process began around the 8th century, producing the first recognizable “green” teas. Tea became a staple of the Chinese diet around the year 1000, and over the next couple of centuries the beverage was introduced to Japan. Buddhist monasteries perfected the art of the tea ceremony shortly thereafter.

Tea was introduced to the West in the 17th century as China begun trading with both Europe and Russia. At this point, strongly flavored teas like oolongs were also being developed, and it was this newer style of tea that captured the interest of Western traders. Over the next two centuries, tea’s popularity exploded in England: tea consumption rose from 20,000 pounds a year in 1700 to 20 million pounds a year in 1800. Perhaps because of the English love for strong tea, tea farmers and producers began to develop even stronger brews especially for export. In the late 19th century, England began planting its own tea plantations in its Indian colony, which lead to the development of their own variety — Assam tea. Assam has even more phenolic compounds and caffeine than the Chinese variety, and it produces a stronger and darker brew. Today, three-quarters of the tea produced in the world is strong and black; however, China and Japan produce far greater amounts of green tea.


All true teas begin from a single plant species: Camellia sinesis. Minute differences in tea processing changes the flavor profile and characteristics of the final tea. Fresh tea leaves are high in defensive compounds and are therefore extremely bitter and astringent. In order to unlock the beneficial phenolics, the leaves need to be pressed, rolled, and (in some cases) cooked and fermented. Green teas retain many of the characteristics of fresh tea leaves, while darker teas like oolongs and black teas harness the tea’s own enzymes to transform these defensive compounds into mellow, pleasant flavors.

The first step in most tea manufacturing is the “withering” step: the harvested leaves are left to sit and wilt for a few minutes or up to a few hours. This resting period sets off a change in the metabolism of the tea that makes the leaves more fragile. The longer the withering period, the deeper flavor and darker color of the resulting tea. A few particularly delicate forms of teas completely skip this step.

Next, the leaves are rolled or pressed to break down the structural cells and release the cell fluids. In these cell fluids are the important enzymes that transform the characteristics of the tea. This enzymatic process is often confused with microbial fermentation, but it is an entirely different process. Enzymatic “fermentation” is relatively short (anywhere from a few minutes to 4 hours) process and is entirely dictated by enzymatic activity. Aromatic compounds are released when the enzymes break down sugar-aroma molecules. The tea enzymes also bind small, astringent phenolic molecules together to create milder, larger compounds. These larger compounds give body to the brewed tea. The longer the tea leaves are pressed, the longer the enzymatic process, and the less bitter and astringent the tea will be.

In order to end the enzymatic process, the tea leaves are heated. If steamed over low heat, the tea will remain fairly subtle. If heated over high heat, tea will develop darker, cooked, and/or smoky flavor. Heating also begins the drying process, which is an important preservation step. In certain teas, like Chinese green tea, the heating step is performed before rolling, producing a very subtle tea.

After the tea is dried, the leaves are sorted and graded by the size of the leaf. In general, the smaller the tea leaf, the faster the extraction time and the lower quality the tea. The very best teas are made from young tea shoots and unopened leaf buds because these leaves are the most vulnerable and contain the highest concentrations of phenolics and related enzymes. These teas must be harvested by hand. Because most commercial tea today is harvested by machine, it will include older and less flavorful leaves and demands a much lower price.


Common Tea Varieties

Green Tea: The original variety of manufactured tea, green tea preserves many of the qualities of fresh tea leaves while heightening desired flavors and rounding out some bitterness and astringency. It is made by cooking fresh or briefly withered leaves to immediately inactivate the tea’s enzymes. The tea is then pressed to release moisture and dried in hot air (for grassy flavor notes) or a hot pan (for roasted aroma).

Oolong Tea: Oolong falls midway in the tea strength spectrum between green and black teas. The leaves are withered until significantly wilted and weakened, and then they are lightly agitated to bruise the leaves. Oolong manufacturers allow a modest amount of enzymatic transformation to occur during this process, waiting until the leaf edges turn red before pan-firing the tea at a high temperature. The leaves are then rolled and gently dried. The final tea has a light amber color and a fruity aroma.

Black Tea: The manufacturing process of this strong Western favorite allows for profound enzymatic transformation by extensive rolling and bruising of wilted tea leaves. The leaves are then left to rest for a few hours and dried in hot air after the leaves have turned coppery brown.

There are many nuanced varieties in between the above three types. White teas are dried before rolling the leaves. Pu-erh teas go through an additional microbial fermentation process. Lapsang souchongs are smoked. Jasmine teas are scented with jasmine flowers. Gyokura and kabesucha are wilted in boxes made of maboo. Hoji-cha is a variety of green tea that is roasted at very high temperatures.

Tea at Home

All teas should be stored in dark, airtight containers to limit exposure to oxygen, sunlight, and moisture. After several months, the aroma and briskness will begin to deteriorate. While neither of those problems are particularly harmful, they certainly don’t contribute to a great cup of tea. However, tea can also grow molds if exposed to moisture, and you absolutely don’t want molds in your tea! See below to learn more about molds.

Teas are brewed using different methods all over the world. The simplest method for brewing is to pour boiling water over loose leaf tea leaves in a teapot and then straining brewed tea out of the pot. However, the water temperature and steeping time can have a huge effect on the final drink. Green teas are typically steeped longer at lower temperatures and black tea is typically steeped for a shorter period of time at higher temperatures. The best way to learn how long and how hot to steep tea is to buy a few types and experiment. Taste as the tea brews and immediately remove the tea leaves once it tastes good to you. Over-steeped teas will taste harsh and astringent. (This problem can be remedied by adding milk and/or sweetener, but these additions also dampen the good flavors of the tea.) In addition, the quality of the water used for brewing can change the flavor of the final tea. Ideally, you should use chlorine-free water with a moderate mineral content.


Coffee History

Coffee is native to eastern Africa, but it has made its way around the world through oceanic trading routes: first it was brought to India, then Java, and finally to the French Caribbean and South America soon afterwards. Today Brazil, Vietnam, and Colombia are the largest exporters of coffee.

The original brewed coffee beverage is made from finely powdered coffee beans and sugar boiled in water. It is a concentrated brew that inevitably includes some coffee sediment and strong, bitter flavor (hence the sugar). It was conceived in eastern Africa and the Middle East, where it is still commonly consumed. Turkey and Greece also serve a version of the drink. This type of coffee made its way to Europe around 1600, and by 1700 it had been modified by the French. There, cooks isolated the coffee grounds in a cloth bag, producing a cleaner and less gritty drink. By 1750, the French had invented the drip pot, called a biggin. This method results in a shorter extraction with less bitterness and astringency than boiled coffee.

The 19th century saw a few more advances in coffee extraction. The percolator, the French press, and the espresso machine were all invented in rapid succession. Espresso, which debuted in 1855, was a particularly important invention. This Italian brewing method forces hot water through finely ground coffee very quickly at high pressure. As a result of the high-pressure extraction, the oil in the coffee beans is emulsified into the brewed coffee, giving the drink a velvety texture and lingering flavor.

Coffee Processing

Coffee beans are the seeds of a plant that is a tropical relative of the gardenia. There are two species: arabica and canephora, which produces robusta coffee beans. Arabica is native to Ethiopia and Sudan and it makes up two-thirds of the international coffee trade. These beans develop a more complex and balanced flavor than robusta, and are preferred by artisanal coffee companies. Robusta is native to humid West Africa, and it contains more caffeine and phenolics and less oil and sugar than arabica. This species of bean wasn’t commonly grown until the end of the 19th century, when it became known for having higher disease resistance than arabica. Today, it is typically found in many cheap grocery store blends and instant coffees.

Like tea, coffee can be harvested by hand or by machine; hand-harvested coffees are most often higher in quality than machine-harvested beans as they allow the harvester to be selective for only fully ripe coffee berries. Once the berries are picked, the seeds need to be separated from the fruit and cleaned. This step is referred to as coffee processing, and it is one of the most important steps for ensuring clean, safe, and mold-free coffee beans.

Coffee can be processed via dry processing, wet processing or a hybrid method called semi-dry. The choice in processing often depends on the environment and resources of the growing regions; dry processing needs hot, dry temperatures and wet processing requires access to abundant clean water.

Dry processing, or “natural” processing is the original coffee processing method. The picked coffee berries are first cleaned and sorted to separate out unripe, overripe, and damaged coffee cherries. The cleaned berries are spread out over a large concrete patio or raised mats to dry to an appropriate moisture content. Because the beans are still covered with the fruit of the coffee berry, they will ferment and transform in flavor. Once they have dried sufficiently, the cherries are transferred to a hulling machine that removes the dried fruit, leaving the bean behind. From there the green coffee beans are sorted, graded and bagged. Almost all robusta beans are processed using this method, as are arabicas produced in hot, dry areas with limited access to water.

Wet processing uses water to sort and clean the beans. First, the cherries are sorted by immersion in a large water tank. Bad or unripe fruit will float and ripe fruit will sink. The ripe fruit is then transferred to a second tank, where it is pushed through a screen to remove some of the fruit pulp. The remaining fruit is removed either through a wet fermentation process or through mechanical scrubbing. Fermented beans are watched carefully to make sure that they don’t acquire sour or “off” flavors. Mechanical scrubbing can help cut down on water use and it increases uniformity of the coffee, but it doesn’t allow for additional flavor to develop. Finally, the beans are washed to remove any excess fruit pulp and dried via machine or in the sun on raised mats or concrete patios. Wet-processed coffees are often considered to be of higher quality than dry-processed coffees, and they are much more consistent in quality.

Semi-dry processing combines the dry and wet methods. The outer fruit layer is removed as it is in the wet method, but then the beans are left out in the sun for about a day to ferment. After this waiting period, the remaining fruit is washed off and the coffee is dried.

The result of each of these processing steps is called green coffee beans. These are the beans that are sold to roasteries around the world. Coffee companies then roast the beans in large drums to transform the green beans to coffee beans ready to brew. Coffee beans can be roasted to temperatures anywhere between 350 and 425 degrees. As coffee increases in temperature, its flavor profile, color, and caffeine content change. In the early stages of roasting, the coffee’s sugars are broken down into various acidic compounds that give the beans a tart flavor. As roasting continues, these acids and their accompanying astringent compounds are destroyed. Bitterness will rise with darkening color. Very dark coffees can be overwhelmed by the “roasted” flavor; poor quality beans are often over-roasted to cover up the off flavors of the beans. Lightly roasted coffee is bright, tart, and high in caffeine. Medium roasts typically have more body and sweeter, richer flavor.

Like tea, coffee is brewed using many different methods. Drip pots, pour-over filters, French press, and espresso are all popular today. Coffee’s flavor is a combination of acidity, bitterness, astringency, and sweetness. More than 800 aroma compounds have been identified in coffee. They include everything from common descriptors like nutty, fruity, chocolatey, and caramelly to more adventurous flavors like flowery, winey, and gamy. Most coffees contain 60 to 180 mg of caffeine per serving.

Decaffeinated coffee is a unique product developed in Germany in 1908. It works by washing the green coffee beans using either a solvent, a saturated water solution, or supercritical carbon dioxide to leach out the caffeine from the beans while keeping the other flavors intact. We haven’t decided if we will serve decaf yet — let us know if you want it! If we do, we’ll only purchase decaf produced using the water method to avoid adding excess chemical solvents to the coffee beans.


Reducing Toxins by Wet-Processing

At Mission: Heirloom, we serve only wet-processed coffee. Why? When processed with care and attention, it doesn’t run the risk of growing harmful molds and aflatoxins. Like spices, coffee beans are particularly susceptible to mold growth in many different stages of production. While some molds aren’t particularly harmful to non-sensitive individuals, there are others that produce potent mycotoxins. Depending on the level of cleanliness and care taken during production, coffee can potentially be contaminated with a mold called Aspergillus ochraceus, which produces a mycotoxin called ochratoxin A (OTA). Roasting the green coffee beans destroys any mold present, but it is only effective against OTA at extremely high temperatures. These temperatures often render the coffee acrid, bitter, and unpleasant to drink. (OTA has been shown to remain in coffees roasted up to 350-480 degrees.) Studies on rodents have associated excessive levels of OTA with cancer, brain damage, and kidney disease in addition to immunosuppressive effects. Since these studies were performed only on animals in extreme conditions, we cannot be sure that OTA would cause these same problems in humans. More study is clearly needed. Until then, it is probably wise to choose higher-quality coffees that do not run the same risk.

Why is wet-processing a better choice? Wet processed coffee beans have less opportunity to grow toxic molds as they are completely submerged in water and are then dried quickly. Thorough, raised-mat drying also reduces the growth of molds. Choosing single-estate beans also runs less risk of mold cross-contamination.

Direct-Trade Sourcing

We purchase our coffees through Intelligentsia Coffee Roasters, who maintain a Direct Trade relationship with all of their coffee growers. Direct Trade is often confused with Fair Trade certification, but there are a few key differences. Like Fair Trade, Direct Trade emphasizes environmentally-friendly growing practices and fair prices for coffee. Unlike Fair Trade, Direct Trade sourcing is an uncertified program that is run directly between the roaster and the grower. It rewards high quality coffee production with higher prices paid per pound and doesn’t require that growers participate in (and pay a fee to) a coffee cooperative. Coffee roasters participating in Direct Trade have a strong influence on the ways in which coffee is grown and produced; it is generally preferred to Fair Trade amongst specialty roasters.

Intelligentsia’s Direct Trade standards are as follows:

  1. The coffee must be of exceptional quality.
  2. The growers must be committed to healthy environmental practices.
  3. The price to the grower or local co-op (not the exporter) must be at least 25% over the Fair Trade price.
  4. The grower must be committed to sustainable social practices.
  5. All of the trade participants must be open to transparent disclosure of financial deliveries back to the individual farmers.
  6. Intelligentsia representatives must visit the farm or cooperative village at least once per harvest season, understanding that Intelligentsia will most often visit three times per year: pre-harvest to craft strategy, during the harvest to monitor quality, and post-harvest to review and celebrate the success.

Since we’ll be serving seasonal Direct Trade beans in our cafe, you can expect to try different beans each time you visit and truly engage with the changing coffee seasons.


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