One note about the numbers: Use them as a guide. The actual caffeine content of the same coffee drink can vary from day to day — even at the same coffee shop — because of various factors, such as roasting and grinding as well as brewing time. The caffeine content of tea also is affected by how long it's brewed. Adapted from Journal of Food Science, 2010; Pediatrics, 2011; USDA National Nutrient Database for Standard Reference, Release 26; Journal of Analytical Toxicology, 2006; Starbucks, 2014; Food and Chemical Toxicology, 2014; Keurig, 2014.
https://www.drugs.com/mca/caffeine-content-for-coffee-tea-soda-and-more
Nick, London UK. 1  Tea leaves have more caffeine than coffee beans before they are brewed. 2  Unmade tea contains more caffeine than unmade coffee, however when you make the drink lots of caffeine is left in the tea leaves you throw away leaving less in the tea you drink than in coffee.
https://www.theguardian.com/notesandqueries/query/0,5753,-25502,00.html
Originally called theine, caffeine was first discovered in tea in 1827. It was later shown that the theine of tea was identical with the caffeine of coffee, and the term theine was then dropped. While the caffeine in tea and coffee are, technically, identical, the experience is different due to three key factors:
https://www.teaclass.com/lesson_0112.html
About caffeine. Caffeine is a naturally-occurring stimulant, found in several plants. Caffeine is water soluble, and is extracted into the brewed cup when preparing tea, coffee, or other caffeinated beverages. The most well-known plants containing caffeine are tea (Camellia sinensis), coffee, and yerba maté.
http://ratetea.com/topic/caffeine-content-of-tea/21/
Raw versus Brewed. Tea in raw form might have more caffeine than coffee, especially tea with lots of buds/tips. However, a cup of brewed tea will usually not contain more caffeine than coffee. Generally less than half, but it really depends on the type of coffee and the type of tea. Factors affecting tea caffeine.
https://www.quora.com/Is-it-true-that-tea-on-average-has-more-caffeine-than-coffee
It found that the average caffeine level in the cups of tea (black English style teas) was 40mg vs 105mg in the average cup of drip coffee. The amount of caffeine in coffee or tea depends on a number of factors, including the method and length of brewing or steeping. With tea, studies also show that leaf location on the tea plant affects content of caffeine in that tea.
https://www.teaclass.com/lesson_0112.html
Most tea has 15-70 mg caffeine / cup. Coffee tends to have 80-135 mg caffeine / cup. It is a myth that green or white teas are always lower in caffeine than black. Any color of tea (black, green, white, etc.) can be high or low in caffeine.
http://ratetea.com/topic/caffeine-content-of-tea/21/
Caffeine Content Of Popular Drinks. SOURCES: National Soft Drink Association, US Food and Drug Administration, Bunker and McWilliams, Pepsi, Slim-Fast.
https://www.math.utah.edu/~yplee/fun/caffeine.html
2 cups of tea = 1 cup of coffee. There are 20mg of caffeine in your average 100g of brewed tea compared to 40mg in the same amount of black filter coffee. But the type of tea, as well as the brewing time makes a difference. 2 colas = 1 tea. We were surprised too.
https://www.theguardian.com/news/2013/nov/27/caffeine-compared-coke-coffee-aspirin-chocolate-tea
Tea leaves have more caffeine than coffee beans before they are brewed. Prepared, however, tea is diluted quite a bit more than most coffees. Each will vary depending on how strong you like it, though. I understand also that the caffeine content in tea is extracted during the first ten seconds of brewing.
https://www.theguardian.com/notesandqueries/query/0,5753,-25502,00.html
what has the most caffeine coffee or tea
Tea has the most caffeine. Tea has the most caffeine than coffee. A tea has the most caffeine.