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Butter Knife Sharpness Tester

Butter Knife Sharpness Tester
April 1, 2020
Contact: Sharpening Supplies
8376 Murphy Dr.
Middleton, WI 53562

Introducing the Butter Knife Sharpness Tester

Butter Knife Sharpness Tester

The lowly butter knife is often used as the gold standard of knife dullness. But until recently, that dullness has never been measured. Everyone was just guessing the theoretical sharpness of a butter knife.

We tried many alternative techniques to measure the sharpness of a knife. Popular examples include shaving arm hair or cutting a piece of paper. We tried that with a butter knife, and we were unable to produce reliable results.

The lack of a reliable method to test the sharpness of a butter knife presented an opportunity for us. A butter knife sharpness tester needed to be developed.


The Butter Knife Sharpness Tester

Test Media

When coming up with a design for our Butter Knife Sharpness Tester (BKST), we decided the proper test medium would have to be utilized. It couldn’t be too hard, but it couldn’t be too soft.

Butter Knife Tester Sketch

The breakthrough came one morning when sharpening specialist, Dan, was having breakfast. After baking a loaf of his famous sourdough bread, he reached out to apply his favorite bread topping. It came to him in a flash, “We should use butter!” he exclaimed to his startled wife and daughter. He quickly left the house and drove to work to share the news with the rest of his colleagues, leaving the rest of his stunned family at the breakfast table.

Considerable testing ensued; it was confirmed that a stick of butter was indeed an ideal test medium to use. After investing considerable time experimenting with paper, wood, and rope as test media, we were happy to focus our attention on the more suitable butter. Whoever would have guessed?

With the test media determined, we needed a way to come up with a quantitative way to determine the results of the testing.

Butter Knife Scientist

Test Fixture

The next step was to design a fixture to hold the butter. The test fixture holds the test media in place so it can be cut. It needed to cradle the butter in a way that would mimic the natural process of cutting butter. From the initial sketch to the finished product, it took many versions to get it right. Some were too tall, some were too wide, but the final version was perfectly in the Goldilocks zone.

Data Accumulator

The Data Accumulator is where it got scientific. We needed help with the science stuff, so we needed someone with proven dedication and technical knowledge. I asked around the neighborhood and found 13-year-old Max from down the street. He was by consensus, best Minecraft player in the neighborhood, so we knew he had the dedication and technical background to help us with our task. In no time he came up with a way to accurately measure the resistance of the test media while it was being cut with a butter knife. He said he used some Arduino thing to handle the electron stuff, but that may also have been the brand name of sports drink he was consuming at the time. It didn’t matter, it worked!



Butter Knife Tester Action

Testing Butter Knife Sharpness

Using the BKST is rather simple if you follow these 17 easy steps:

  1. Remove BESSie Certified Test Media from the refrigerator.
  2. Let it sit out on the counter for 47 minutes.
  3. Test media should be at exactly 60.5 degrees Fahrenheit for an accurate reading.
  4. Measure temperature of test media using instant read thermometer (not included).
  5. If too warm, place in refrigerator for 4 minutes.
  6. If too cold, leave out for another 7 minutes.
  7. Retest temperature.
  8. Repeat steps 4 through 7 until your temperature is exact.
  9. Place 60.5 test media on Test Fixture.
  10. Twist thumb screws until a torque measurement of 17 inch/pounds has been reached. Use click type torque wrench (not included) to measure torque.
  11. Place Test Fixture on Data Accumulator.
  12. Measure temperature of butter. If it has changed, repeat steps 4 through 11.
  13. Tare the Data Accumulator to compensate for butter weight.
  14. Take butter knife and measure temperature. It must be between 70.7 and 72.3 degrees Fahrenheit. If too cold, warm it up with your hands, if too warm, place it in the refrigerator.
  15. Take first reading by plunging the knife through the test media very slowly.
  16. Record reading.
  17. If reading was faulty, repeat steps 1 through 16.


Bessie Logo

BESSie Certified Test Media

BESSie Certified (Bovine Evaluated Sharpness Standards International Edgemasters) means you have a global standard backed by a trusted organization certifying the accuracy of your results.

BESSie Test Media was the result of years of development and many delicious sandwiches. While almost any butter can be used to estimate sharpness, only the BESSie Certified Test Media is calibrated to ensure your tests can be reliably repeated. In fact, BESSie is the only universal and quantifiable butter knife sharpness test media in use today.

Carefully Crafted Farm to Table Test Media

Any dairy farmer knows, good butter comes from quality milk. We’ve selected the finest local Wisconsin dairy farms to produce milk for our Butter Test Media. Only the finest cows can meet our rigorous standards of quality. Once selected, our cows graze on carefully manicured grass, are fed the most carefully baled hay and even drink a daily Spotted Cow to encourage relaxation. Only under this strict diet can we reliably produce test media that cuts with precision and consistency.

Reusable Test Media

In today's environment, it is popular to reuse or recycle rather than throwing something in the trash. We’re proud of our environmental record with our 100% reusable test media. Once used to test your butter knife, there are many uses for the test media. Some of the most popular uses are on toast, banana bread, grilled cheese, and baked potatoes.


Competitive Test Media

Margarine Based Copycats

Our competitors have tried to copy us and get around our patents by using margarine. Not only does it taste like garbage, but the test media is never as reliable as our true BESSie Certified Test Media. Margarine doesn’t have the creamy smoothness of true Wisconsin butter required for a truly accurate test. As margarine warms up, the coefficient of melting is very unreliable, so temperature swings dramatically affect the data.

Limited Supply. Ships when the cows come home.


This April 1st joke was posted April 1, 2020. For serious sharpness testers please visit Edge-On-Up Testers page.

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