STEELPORT Coffee Patina for Protection and Presentation

STEELPORT Coffee Patina for Protection and Presentation


STEELPORT 6" Carbon Steel Chef Knife example

“There are no secrets in the etched blade, all is revealed.”

– Ed Fowler, ABS Mastersmith

A new STEELPORT knife is immediately recognizable by its dark two-toned patina with visible grain patterns and temper line. Significant time, energy, experimentation and… believe it or not, coffee, went into developing that unique finish to meet our uncompromising standards of iconic design, functional detail and handcrafted locally.

Our goal is to provide every customer the best advantages of a well patinated blade from their very first use, while also only using natural products to achieve that effect.

Making a STEELPORT knife is both science and art. Unlike mass-produced stamped blades, every STEELPORT blade is handcrafted using traditional materials and methods, with some modern innovation, giving each knife a unique character. One of the final steps when making our blades is forcing a patina through a custom etching process we developed, which serves multiple functional and aesthetic purposes.

And thanks in part to our unique patina, every blade we produce has visible reminders that it was carefully crafted by expert artisans, one blade at a time.

STEELPORT coffee patina bath

What is Patina?

Patina is what gives material like steel, cast iron, bronze and copper their beautiful, complex aged look.

Patina is a controlled layer of oxidation. It can protect against the damaging (red) rust that forms when water and liquids are left on the surface of metals like steel and cast iron.

Patina occurs on many materials naturally with time and use. It can also be intentionally added or ‘forced’ through various different etching processes.
STEELPORT carbon steek knife patina grain

Why We Force Patina

A forced patina has long been part of a bladesmiths’ toolset, showing the finer details of the steel. This was well put by the legendary bladesmith Ed Fowler: “There are no secrets in the etched blade, all is revealed”.
In addition to the rust protection an initial patina can provide, our patina also acts as a quality control point. STEELPORT knives are forged 52100 carbon steel that we put through a proprietary 8-step cryogenic heat treatment process by hand, one-at-a-time, to achieve our prized differential heat treatment. When we force a patina at the end of our knifemaking process for each knife individually, it brings out the finer details of the blade so our team can carefully inspect exactly how the steel grain flows, where the temper line is (showing where the steel hardened to 65HRC on the blade edge and softer at 30HRC on the spine), and any imperfections that wouldn’t meet our highest standards.

The dark two-tone effect created by the combination of our differential heat treatment and unique natural patina process results in a beautiful modern heirloom to proudly display in your kitchen from day-one.

Coffee patina

STEELPORT’s Unique Method

Patina occurs fastest by exposing the blade to acidity. This is why cutting very acidic foods (e.g. citrus fruits) changes the color of your carbon steel blade more drastically than cutting less acidic foods (e.g. vegetables).

The most common products used in the cutlery industry to etch a forced patina onto a carbon steel knife are etching chemicals, like Ferric Chloride (FeCl3).

But our team was committed to finding the best natural product to achieve the effect we wanted. We experimented with different natural ingredients like vinegar, mustard, lemon juice, wine, and other acidic food products in various combinations and concentrations to compare with the chemical etchants.

Ultimately, we found that simply submerging our blades in strongly brewed (to a level similar to espresso) hot coffee achieves our ideal results!

We heat up coffee, keeping it at a consistent temperature, and steep each blade for less than 1 hour. Then we carefully rinse and dry the blade, and it’s ready for final handle assembly and sharpening.

Coffee provides great uniform protection and a beautiful color on the blade – and it’s a product found in abundance here in Portland, Oregon.

bag of coava coffee

Using Locally Roasted Coffee

Portland is a town internationally celebrated for its artisan coffee scene. Once we knew we were using coffee for our patina process, it was a no-brainer that we should team up with one of our favorite local roasters – Coava Coffee.

Coava is both the coffee the STEELPORT team drinks every day in our factory shop and the coffee we use to patina our blades.

Coava’s founder Matt Higgins is a veteran barista and roaster who started the company out of his garage and bootstrapped it by repairing motorcycles. Having spent years in specialty coffee, Matt dreamed of starting his own company where he could roast and prepare coffees that would be exciting for professional baristas and inviting to everyday drinkers. Matt knew that in order to accomplish this goal, sourcing exceptional “coava” (i.e. unroasted, or “green” coffee) would have to be the bedrock upon which his entire company was built. So he studied agriculture, farm practices, and sustainable business. He sought farmers who were committed to producing quality crops, and focused his attention on under-sourced regions. His hard work and willingness to go above and beyond eventually earned him a reputation among coffee producers as a respectful, diligent, and honest person. Coava is now one of the premier coffee roasters in the United States and roasts some of the highest scoring coffees in the world.

It’s a story our team strongly relates to. Our two companies’ shared commitment to the best quality, sourcing, and craftsmanship makes Coava a perfect partner for STEELPORT.

Roasting Coava coffee beans

A Full-Circle Process

We believe in recycling as much as possible at every step of our process, which is part of why a coffee patina works so well for us.

Our patina liquid is made from excess coffee grounds that would otherwise go to waste. Then, when our coffee patina mixture needs to be replaced, we use the leftover liquid to fertilize the plants outside of our factory shop and improve the green spaces around our building.

Patina Changes Over Time

A STEELPORT is an heirloom quality knife that will last for a lifetime of meals and memories.

Every knife starts this culinary journey with the naturally-produced coffee patina layer we’ve provided, but with time, use and proper care, it will develop its own unique patina layers. A regular care routine of rinsing the knife after each use, ensuring it’s dry at all time, and oiling for longer storage will ensure that the best patina develops over the years of use.

Based on your cooking habits and the different foods you cut, every STEELPORT will develop different colors on the blade over time, like black, blue and purple. No two knives will end up looking exactly the same, and we love to see how different customers’ patinas develop.

The unique color and pattern of the patina your knife gains over the years will tell the story of all the loving meals it helped prepare.

STEELPORT patina example gif