Caffeine and pH Levels
Here are some interesting facts about caffeine levels in high quality Arabica coffees. It does not matter what roast level the coffee is; light, medium or dark. In reality, dark roasts have no more caffeine than light roasts.
The caffeine levels are determined by the length of coffee extraction. The brew method determines how much caffeine is in your cup. In short, the longer the extraction (brew time), the more caffeine. So since a shot of espresso brews for between 20-30 sec, it has significantly less caffeine than a cup of French press which brews for approximately 4 mins. Here are some examples of caffeine content per brew time compared to other beverages:
1z Espresso 60mg; 12z brewed 150mg; 12z French press 250mg; 8z black tea 60mg; 8z
green tea 40mg; 12z Coke 35mg; 12z Pepsi 40mg; 12z Mountain Dew 50mg
Also, here are some interesting facts about pH levels in coffee (acid). If after drinking coffee, specifically black coffee you feel like you have had too much acid, it's likely not the coffee. We obviously do not give medical advice, however it is very common for people to have issues with caffeine over acid that feels like acid reflux. It is likely the caffeine that is affecting your stomach or the caffeine that relaxes the muscle in the esophagus causing the coffee to 'come up' on you; it's likely not the coffee's acid causing anything. We suggest consulting a doctor to determine the issues. However, here are some findings of ours when we tested our coffees pH levels:
Brazil Lite Roast pH 5.4, w/milk pH 6; Brazil Med Roast pH 5.9, w/milk pH 6.3; Sumatra Med Roast pH 6, w/milk pH 6.4; Milk (alone) pH 6.8; water (alone) pH 6.6