To Dome Or Not To Dome

As I was re-reading The World Atlas of Coffee I stumbled upon the instructions for the vacuum pot, otherwise known as the siphon. I realized that the instructions in the book were different than how I was taught to make them at work. Curious as to why we have different steps I explored online and found that this is actually a heavily debated subject. So naturally I had to try it out!

Both methods of brewing begin with bringing water to a boil in the bottom chamber, inserting the filter in the upper chamber, and sealing the upper chamber to allow for the water to rise. Where the two methods differ is the actual brewing of the coffee.

For the first method, the method from the Atlas, you initially stir your coffee in at the beginning to ensure that all of the grounds are saturated. After thirty seconds of brewing you gently stir the contents to keep all the grounds saturated. After sixty seconds, you remove the coffee from its heating source, and stir once clockwise and once more counter clockwise. The goal is to keep the grounds from sticking to the walls as the coffee draws.

The second method requires four stirs at the start, halfway through, and at the end. Each time you stir you try to fold the grounds in to ensure that they are completely saturated. The entire brewing process takes 90 seconds. With each stir you are creating a vortex. After 90 seconds is up, you remove the coffee from its heating source, preform the final 4 stirs and watch for the dome to form as the coffee draws.

In a taste test comparing the two methods, myself and a few other baristas found that both the aroma and flavor of the coffee were more present with the coffee produced with a dome. I suspect this has to do with the extraction time. More is extracted over the 90 seconds than over 60 seconds. It is important to note that a longer brewing time does not automatically mean better flavor. In fact, if we brewed the first method for the same amount of brewing time as the second it would result in an over extracted and burnt flavor. Both of the resulting coffees tasted wonderful and overall it was an exciting experiment. I might have to try it again!