Some people do not like the metallic taste that "carbon" steels can impart to food items during cutting.
In the name of science, I have sacrificed my daughter as a test subject. She did not know the purpose of the test and was blinded to apple type and knives used:
Materials and Methods: Two apple types (Granny Smith and "Explorer", I think). Two carbon/non-stainless steel blades (CPM-M4 and SuperBlue) and a stainless blade as a control (M390)
All blades were cleaned of anticorrosive coating (Fluid film) using white spirit and then washed and dried.
Precautions were taken to avoid cross-contamination of blades and slices. Same sector of apples used to reduce variability of fruit skewing results. Slices were of similar size and thickness. Each test was repeated to assess intra-observer reliability. Order in which samples were tasted was changed to reduce "first-taste" bias.
Results:
The outcome was surprising. On each occasion, regardless of apple type, the subject reported a preference for the slices cut with the Superblue steel. There was no repeatable difference reported between CPM-M4 and M390 (Though a Type II error is possible due to small sample size; no β calculation was performed prior to the study.)
The subject did not report any "metallic taste" at any stage.
The test was repeated but leaving the slices in contract with the blade surface for much longer than would normally occur. The results were the same.
I also tasted slices (un-blinded) and could definitely taste the difference, with Superblue being most metallic, though only really intrusive when the side of the slice which had been in contact with the blade was placed onto the tongue. I struggled to distinguish a difference between M4 and M390
Conclusion:
Possible conclusions:
1. My daughter has a poor sense of taste, or likes the taste of SuperBlue on apple.
2. The metallic taste is only consciously appreciated when the subject is expecting it (unlikely.)
3. The study design is crap.
I suspect 3 is the most likely to be correct, but it kept me out of trouble for a short while.
In the name of science, I have sacrificed my daughter as a test subject. She did not know the purpose of the test and was blinded to apple type and knives used:
Materials and Methods: Two apple types (Granny Smith and "Explorer", I think). Two carbon/non-stainless steel blades (CPM-M4 and SuperBlue) and a stainless blade as a control (M390)
All blades were cleaned of anticorrosive coating (Fluid film) using white spirit and then washed and dried.
Precautions were taken to avoid cross-contamination of blades and slices. Same sector of apples used to reduce variability of fruit skewing results. Slices were of similar size and thickness. Each test was repeated to assess intra-observer reliability. Order in which samples were tasted was changed to reduce "first-taste" bias.
Results:
The outcome was surprising. On each occasion, regardless of apple type, the subject reported a preference for the slices cut with the Superblue steel. There was no repeatable difference reported between CPM-M4 and M390 (Though a Type II error is possible due to small sample size; no β calculation was performed prior to the study.)
The subject did not report any "metallic taste" at any stage.
The test was repeated but leaving the slices in contract with the blade surface for much longer than would normally occur. The results were the same.
I also tasted slices (un-blinded) and could definitely taste the difference, with Superblue being most metallic, though only really intrusive when the side of the slice which had been in contact with the blade was placed onto the tongue. I struggled to distinguish a difference between M4 and M390
Conclusion:
Possible conclusions:
1. My daughter has a poor sense of taste, or likes the taste of SuperBlue on apple.
2. The metallic taste is only consciously appreciated when the subject is expecting it (unlikely.)
3. The study design is crap.
I suspect 3 is the most likely to be correct, but it kept me out of trouble for a short while.
Love the pix, too. :thumbup:
