15

Rate Tea tells us this is a myth: Many tea companies, and even some reputable entities such as the U.S. Department of Agriculture, have made misleading generalizations about the caffeine content of broad classes of tea. It is a widespread myth that black tea contains more caffeine than green tea, and another myth that white tea contains the least ...


13

I believe that the following study provides a definitive answer: Application of high performance liquid chromatography to the analysis of some non-volatile coffee components From the abstract: High performance liquid chromatography (HPLC) was applied to the analysis of caffeine, trigonelline, nicotinic acid and sucrose in Arabica and Robusta coffee. ...


13

I recently observed the effect of time of steeping on caffeine content in tea. We used High Pressure Liquid Chromatography to determine the levels of caffeine in Green Tea in samples that were steeped for 1, 2, 4, 10, 15, 30, 60, and 120 mins. The concentration of caffeine over time did not show any significant trends. Our results suggest that caffeine ...


12

Its interesting to see all of the responses. At Kohana Coffee we make cold brew coffee concentrate commercially. Our caffeine numbers come to about 80 mg of caffeine per oz of cold brew concentrate. Our mix ratio for use is 1 part concentrate to 2 parts milk or water. Typically, a 16oz cup of iced coffee would be 3 oz concentrate, 6 oz milk/water plus ice to ...


12

The most commonly used method is the Swiss Water Process: A batch of unroasted beans is soaked in hot water. Caffeine is water soluble, so it's extracted from the beans. However, some of the other substances that give coffee its flavour ("coffee solids") are also water-soluble and are also extracted. The first batch of beans is discarded and the caffeine ...


9

Caffeine is water soluble, but it takes a bit of time to be absorbed by water. What determines the caffeine content of a coffee process is how much time it spends with/in water. For example, a bodum French press will pick up more caffeine from the coffee since the grounds stay soaked for a while. Drip coffee will have more than a single espresso (common ...


8

There are two factors that matter: the duration of steeping, and to a lesser extent, which portions of the tea plant are used. In Japan, most people brew Japanese green tea for a matter of seconds, unless they are brewing a tea like gyokuro that has better results with a low-temperature steeping. Oolongs also tend to have a shorter infusion time than black ...


8

In case you're looking for a scientific approach, this paper has some plots showing the amount of caffeine extracted as a function of temperature and time. Look for the "CA" label in figures 2-5. They steep the bags for 30 seconds at a time and record the relative & cumulative amounts of caffeine (and other ingredients) extracted from the tea.


8

Caffeine is bitter, tea isn't too bitter because as you mentioned it's only got 40mg of caffeine. If you then triple the amount in there it's going to taste that way. Try adding 3 tea bags to your cup and I'm certain it'll taste just as bitter. Energy drinks have copious amounts of sweeteners added hence why they don't taste like caffeine. If you are hell ...


8

TL;DR: (1) they are estimates based on a single sample and (2) No. In order to pre-determine the exact amount of caffeine in a cup of tea, you would have to know many factors (as Choice Organic Teas says): The exact tea blend and batch you're steeping; The storage age (and conditions) of the leaves; The exact steeping method, including times, temperatures, ...


7

I work at Peter Larsen Kaffe in Denmark, where I make cold brew. I used 1 kg of coffee and 10 liter water, letting it stand for 17 hours. Then I sent it to Steiner Laboratory, where they measured the content of caffeine to be 920 mg per liter of the cold brew.


5

The pot will have more caffeine. You are right that the concentration of the final solution is determined not only by steeping time, temperature, etc., but also by the amount of water available to dilute the stuff coming out of the tea, including caffeine. It will reach balance earlier with less water. So more water will get more of the different compounds ...


5

There seems to be no well-understood correlation between the level of caffeine in tea and the type, processing, or brewing. Actual data seems hard to get hold of, because measuring the caffeine content of a cup of tea requires expensive laboratory equipment. Tea: history, terroirs, varieties by Gascoyne, Marchand, Desharnais and Americi (Firefly Books, ...


5

Obviously the flavor of loose-leaf tea is usually considered superior, but there are a few other issues to be considered. (1) As others have noted, most tea bags contain tea that is graded as "fannings" or "dust," which are official terms for smaller bits of tea leaves. (For more information, consult the details on tea grading here.) However, it should ...


4

I agree with Jefromi, except that the powdered forms of Japanese tea (Matcha) may have significantly more caffeine in the final brew than other teas. This is according to the analysis of 35 teas reported in the 2011 book Tea: history, terroirs, varieties. The table on page 254 reports matcha made with 1.5g of powder as having more than twice the caffeine ...


4

From what I've read, caffeine content can be variable even within varieties. There are possibly seasonal variations, variations in harvesting and processing technique, variations in the original plants... Psychological effects (e.g. what smells perky to you) might be just as strong, and steeping for 10 minutes instead of 5 might make as much difference as ...


4

There have been a number of scientific studies addressing the question of how much caffeine is extracted depending on brewing time. Perhaps the most cited is from 1996, but a 2008 study (carried out to debunk the myth that tea can be decaffeinated with a 30-second steep) also gives some useful data with a variety of teas. To address your question ...


4

Posted from: http://coffeefaq.com/site/node/15 by Daniel Owen: It really depends on how you measure the caffeine. When coffee is roasted the beans loose some water content (somewhere in the 20% range give or take a few percent). At the same time it is losing weight it is gaining size. This leads to a situation that makes answering this question a little ...


4

This study specifically addresses the question regarding multiple infusions: Results for all kinds of tea samples showed that the second tea infusion contained the highest contents of caffeine, catechins, and gallic acid when bag teas were steeped in 70°C water. It was different from that steeped at 85 and 100°C, the highest contents existed in the ...


4

This question is nearly unanswerable. Typical caffeine content data is given as a range based on the normal brewing factors of each method, there isn't data for abnormal methods i.e. french press with fine grind or espresso with coarse grind. Typical caffeine contents: 3oz Espresso double shot: 70-200mg 8oz drip: 60-100mg 6oz French Press: 80-100mg 6oz ...


4

"The addition of “phantom aromas,” such as vanilla, berry, citrus, bacon or even cheese, can distract the brain from acknowledging a bitter to taste." "Other additives can mask or “mitigate a bitter taste.” Lactisole, for example, made from carboxylic acid salt derived from Columbian coffee, can negate sweet taste. An allosteric modulator can change a food ...


4

If it really has to be pills, then I guess you need to mix in something that dissolves more easily than the caffeine powder. Powdered sugar seems like a good candidate. I found a couple references to people using it as a binding material for other pills, so presumably it'll work. Depending on how you're making your tea, you could also add the pill while you'...


4

There are two main traits of tea which deliver the punch you talk about: Caffeine: this is a stimulant, and there is wide variation on the amount of caffeine in black teas depending on a number of factors. Here is a good article which goes into some detail on caffeine in tea. A simple way to put it is that variety doesn't mean much, one assam may have much ...


4

Yes, 7-12mg is a perfectly reasonable, very conservative amount. 12mg of caffeine is about equal to the amount of caffeine in a liquid ounce of 'average' coffee. (Source USDA) Take care not to pack the scoop. Pure caffeine is a potentially dangerous ingredient. Microscoops vary even more than what is implied by your question, I've seen them as large as 50mg;...


3

Your question lumps "flavor/caffeine" together as if they're one item but in fact tea (or coffee) has a variety of chemical compounds that dissolve in water to varying amounts over time (also depending on temperature). Caffeine in particular is readily soluble in water and I would expect basically all of the caffeine to dissolve quickly, making the total ...


3

Coffee foam/bubbles is made up of a mixture of proteins, sugars, oil droplets, caffeine etc, and the lifetime of a bubble is highly dependent on the composition of its membrane. Given that decaf is coffee that's been solvent extracted, it wouldn't be at all surprising to see its different composition affecting bubble lifetime. However, no one seems to have ...


3

Caffeine is much more soluble in hot water, true. But 100mL of room temperature water will still dissolve 2000mg of caffeine, so carrying capacity of water isn't a limiting factor. The better determinant of caffeine content of brewed coffee isn't temperature at all! It's... the caffeine content of the roasted beans. Roasting decomposes caffeine, so lighter ...


3

There are so many conflicting opinions on this, but I have noticed that there are also many "recipes" for making the original coffee concentrate. One recipe calls for a coffee/water ratio of 1oz/12oz (1 part to 12 parts) and another recipe says to use 1/3 cup of coffee to 1 cup of water (1 part to 3 parts). The Toddy company tested their coffee, made with ...


3

You probably need to distinguish between coffee and caffeine. Caffeine is a chemical compound that is a central nervous system stimulant. It is basically just bitter. But coffee contains a load of other compounds that create the coffee taste. Those that affect the human stomach most are tannins, acids and bitters that stimulate the secretion of stomach ...


3

What you read online are all estimations. It's impossible to determine the exact caffeine content of a cup of tea because: Everyone applies a different leaf-to-water ratio when steeping tea. The higher the temperature applied the more caffeine is extracted. Leaves that consist of more buds, contain more caffeine. However, in practice those teas are often ...


Only top voted, non community-wiki answers of a minimum length are eligible