Water Quality Experiment
27th January, 2017
by Jamie Thomson, Business Development Manager Vic
The purpose of this session was to investigate how water with different mineral contents interacts with and contributes to the flavours in brewed coffee. This knowledge helps us understand how to extract the best flavours from our coffee and can be applied in a café or competition setting. It also helps us to best tailor our roast profile for the water available to our consumers.
Water is not a good solvent of flavours in coffee. You need minerals to extract flavour. Many people serve hot filter or cold brew using stand-alone apparatus such as a Moccamaster or brew by the cup options, so having a pre-determined water solution could assist in producing a better product.
Our R&D team dive into the world of water (figuratively speaking) in a bid to find out how water with different mineral contents affected the flavours in a freshly brewed cup of coffee.
Discovering what works best can help in barista competitions as well as assist wholesale customers in making the best coffee they can.
Water makes up 98-99% of your brewed coffee, so it makes sense that it contributes to the flavour of your coffee and that different mineral contents can enhance specific flavour profiles.
The team predicted that water with lower ppm would provide a lighter flavour and more acidity whilst heaver waters create richer cups with more juicy, sweet flavours.
We used three different Veneziano coffees in the experiment:
El Salvador Natural
Kenyan PB Washed
Colombia Caturra Washed
The following waters are used to test what water is best across the board:
Distilled – 0ppm
Urn – 25ppm
Voss – 49ppm
Spiked distilled (Epsom salts and bicarb soda) – 105ppm
Evian – 360ppm
Other equipment required:
5 Bonovita kettles
To determine the water we believe produced the best result, we tasted the different coffees with the different water solutions. This cupping method removes all other variables when brewing coffee so we can assess the results with clarity around the impact the water made.
We used five Bonovita kettles filled with each of the different waters and set three cupping tables with five bowls of each coffee. As a group, we each cupped and scored the coffees using simple scoresheets and our flavour perception.
What’s the verdict?
Voss was the number 1 rated water across the tables. Its mineral makeup is similar to the urn water, but the slightly higher ppm balanced the coffee better.
The urn water was near to or the highest scoring on average. As it is the water that we cup with daily, our roasts are calibrated to this water. If a roast does not cup well, it is re-roasted. It gave the cup a familiar and quality driven result.
The distilled water worked well with the Kenyan as it brought out its vibrant acidity, but as it cooled, it become rather hollow and didn’t extract enough flavour in the coffee to offer balance or sweetness.
The spiked water delivered a consistently richer cup but not always the preferred, however with some modifications it could be adapted to taste preferences.
Evian placed last because of its high reading of bicarbonate and calcium. The bicarbonate reacted in the cupping bowls to give an effervescent appearance, and the calcium content presented each coffee with a chalky taste and texture. Each cup had a heavier mouthfeel due to the higher mineral content, but the was no clarity of flavour present.
I have since used the spiked water at different ratios of minerals and produced great results in my Brewing Fundamentals class. This IP would be great to help wholesale accounts get the best out of their alternate brewing.
This experiment has proven that water makes a significant difference in how a cup of coffee tastes. However, personal preference will always differ from person to person. The quality of the minerals is just as important, if not more important, than the quantity of the minerals. The urn water scored high across the board, showing how well our roast team and production are calibrated given this is the water solution we cup with on a day-to-day basis.