What kind of coffee with the highest caffeine content is bitter and refreshing? is Manning black coffee bitter?

What kind of coffee has the highest caffeine content? Is the deeper the coffee is roasted, the higher the caffeine? In fact, the deeper the coffee is roasted, the more caffeine is lost, so the lightly roasted coffee beans are more refreshing. The reason why light baking has a higher caffeine content than deep baking.

The deeper the roasting, the lighter the weight of the coffee beans after roasting. In general, a coffee bean will be 11%, 13% lighter after shallow baking than that of raw beans, and 15%, 17% lighter than that of raw beans after deep baking. In addition to the water content of raw coffee beans, there are other soluble substances, including caffeine. According to a report by the Coffee Science and Information Association, the caffeine content of the same coffee beans grown in the same area is 1.37% after light roasting, while the caffeine content after deep roasting is 1.31%, which is only a tiny difference of 0.6%. If you are eating coffee beans directly, it can be said that there is no difference. But! Through different extraction methods, the content of caffeine in coffee solution can be very different!

The time of coffee extraction determines the content of caffeine. as one of the soluble substances in coffee, the content of caffeine in water will be higher with the change of extraction time. It is important to note that caffeine is very resistant to extraction and will not speed up the dissolution of caffeine in water because of the high extraction temperature. In other words, the caffeine content of the same variety of coffee beans grown in the same region will be higher than that of trickling / pressurized extraction. Take the same variety of coffee beans grown in the same region as an example: it often takes more than 8 hours to make cold-extracted coffee. 150g coffee liquid is extracted by 15g coffee powder, and the caffeine content is about 200mg. It takes 4 minutes to make coffee in a pressure pot, with 225g coffee liquid extracted by 15g coffee powder with a caffeine content of about 120mg, hand-brewed coffee for about 2 minutes and 30 seconds, and 15g coffee powder with 225g coffee liquid with caffeine content of about 60-90mg. Italian coffee machine extraction time is about 30 seconds, 15g coffee powder extract 30g coffee liquid, caffeine content is about 85mg