Here's how you do it:
- Brew two pots of coffee - one with spring water & one with regular tap water
- Give several family members or friends small cups off coffee from both coffee pots
- Asked them to prepare the coffee the same way they normally would and try them both
- Have them vote on which cup tastes best - be sure and not give any hint as to which ones which
- A way to do a double-blind test is to have someone else pour the coffee and you hand them out. Have the person that poors the coffee mark which one is which on the bottom of the cup. That way, neither you, nor your family or friends know which is which.
Which Water is Best for Your Coffee?
When I tried this with my family, without exception, everyone knew which cup was made with spring water and they liked that cup much better. I conducted a smaller version of this test using filtered water and regular tap water, and while filtered water won out it was harder to tell the difference.
The coffee brewed via the filtered water from our home water filter system was a little sweeter and acidic in taste while the tap water-produced coffee slightly more basic with a metallic aftertaste.