The Flavors of Metal Imparted During Boiling

I’ve lost some important notes, likely because I procrastinated too long to write this post. I did a salt tasting a few months back and had the intent to post my results. I guess the paper is lost to time, lesson learned. Here’s something else.

Tuesday, January 10th 2017

Using a stainless steel, pure copper, and pure iron kettle should produce different results in the flavor of water. What are those flavors? I will do my best to describe them using my stainless steel induction kettle as the standard since I believe it doesn’t impart flavor.

Variables:

• Boiling time (controllable)
• Surface contact with boiling vessel (somewhat uncontrollable)
• Types of water used (controllable, will be using ‘Q Still’ water)
• Strength of heat used (controllable, will be using max flame on gas burner)
• Drinking temperature (somewhat controllable, will be drinking when it’s at a reasonable heat)

To prepare my palate for the test I will drink a cup of hot water from the induction kettle every 10 minutes starting from 4pm until 11pm when this test will begin.

Induction Stainless:

As expected, the water is very neutral. It feels to be on the hard side (which is unusual because it’s filtered?) but has no flavor. The finish is clean/sterile and leaves the roof of my mouth feeling bare and vulnerable. It washes the saliva from my mouth causing it to feel quite dry. I noticed that as I got closer to the bottom of the kettle there were calcium flakes floating on the water (scale build-up?) which seemed to give the water a slight metallic flavor and more texture.

Iron:

The aroma of the water is dull and metallic. If I could be so bold as to say it smells like it is quite hard and has a lot of minerality (esp calcium) The aroma has a dusty basement/furnace room kind of thing going (of course it’s very subtle). The water feels very heavy, has no metallic flavors but remains dry, tasting like stainless. Texturally it feels quite soft. It is slightly sweet tasting.

Copper:

The water has a sour (rancid?) smell to it; not unlike a garbage dumpster. That’s a very subtle aroma, but it’s noticeable — like a very clean garbage room (LaCaille’s for example.) There is an up-front heaviness to the water, and a dull metallic coppery finish (like the copper wire used in those little hobby craft motors) the water tastes slightly sweet. The sweet metallic flavor lingers and is not unpleasant. My mouth doesn’t feel as dry as it did with stainless or iron.