How flow can help you extract fresh or old coffees

Adjusting the water flow means controlling exactly how many grams of water per second will pass through the coffee puck, so that the barista can target the ideal recipe for any roasting type and coffee selection or create different coffee profiles with the same beans.

This is why Dalla Corte has chosen to develop a patented technology to regulate water flow, the Digital Flow Regulator, available on commercial espresso machines Zero and Mina. Let’s see a couple of recipes that can help us with our coffee!

Recipe nr.1 - How can I fix old coffee using flow profiling?

We can consider coffee to be old when the roasting date is between 16 to 30 days before extraction. If we were to use a traditional flow of 10 g/s - 10 grams of water per second - for the entire extraction, the resulting cup would taste flat, with low sweetness and a weak body.

We can improve old coffee by activating the first step at 7 g/s for 3 seconds and ramping up the second step to a flow of 9 g/s for 7 seconds – this way we’ll extract more body and more texture. Next, change the flow to 5 g/s till the end of the extraction to reduce the risk of bringing oxidized flavours into the cup and showcase the bean’s sweetness.

With Mina this can be done through the Mina app, while on Zero you can move the group’s lever between the four preset flow rates.

Recipe nr.2 – What if my coffee has just been roasted?

When coffee is roasted, there are gases (mostly carbon dioxide) that form inside the bean. If your coffee was roasted in the last 5 days, a bulk of the carbon dioxide is still leaving the beans, which would negatively affect the flavor of your coffee and create an uneven extraction. If we were to use a traditional flow of 10 g/s on fresh coffee, we would extract bitter flavours, effervescent texture, sharp acidity and underdeveloped sweetness.

To improve fresh coffee we can start the extraction with a very gentle flow of 5g/s and hold it for about 10 seconds. This will result in a slow and soft pre-infusion that will bring clarity to the cup and develop sweetness without bringing carbonic flavours into the cup. After that we still work with a low flow profile of 7 g / s till the end of the extraction letting the acidity shine.

We’ll share more guidelines to help you create your own flow profiling recipes! We’re going to talk about light roasts and dark roasts, keep following us at @dallacorte_espresso #makeitbetter