One for the Chemists

[Fabnosh]

Morning

A week or so ago we were out in the lovely weather, dropped a youngster and decided to have a bit of a woodland sizzle up and make the most of the environment. I popped out a backstrap and into the pan just using a little of the animals own fat for cooking lube.

I've more knives than is probably healthy but on this occasion out came the Mora - great edge, very effective but nothing special. It's cleaned a lot of deer and the blade has been used and abused but always cleans well and stays sharp. After cooking the backstrap I sliced it and we sat down down to some truly fabnosh.

When I was clearing down the cooking stuff, I wiped over the knife and it had massively discoloured - it looks like it been colour hardened. The surface it totally smooth but whatever caused the discolouration is very hard indeed and has resisted every non-abrasive cleaner I have. It'll no doubt succumb to abrasive cleaning but I'm intrigued what could have caused it.

I'm guess the denaturing of something in the meat caused by the heat must be the cause but I've no idea quite what.

Thoughts anyone?

FN

 

[BRYAN]

Perhaps the previous owner of the meat had been eating something acidic, like blackberry's.

 

[biffo]

If you take a carbon steel knife and apply vinegar to the blade it will ‘parkerize’ it and turn the blade black. That’s a good way to avoid rusting. Maybe the process you have encountered has happened in a similar way??

 

[Fabnosh]

A possible but given that when uncooked there was no discolouration at all I'm assuming that it wasn't baseline chemistry and that the heat of cooking did something.

FN

 

[Scandially]

Blood can tarnish steel.

 

[sh1kar]

5 Essential Ways To Fight Rust Formation On Carbon Steel Kitchen Knives

Carbon steel kitchen knives are easier to sharpen, but maintenance can be a little tricky. We've listed 5 ways to prevent rust from forming on the blade.

www.knifeplanet.net

 

[sh1kar]

Home Page

 

[Steff]

Mora‘s come in carbon steel and stainless steel. Which one is yours?

The pictures suggest it is stainless.
Was the only heat it got that of the cooked meat or did you use the knife also to stir up the fire?

 

[Fabnosh]

It's the stainless version. It was only to slice a medium rare backstrap - no fire poking.

FN

 

[Sharpie]

It's the stainless version. It was only to slice a medium rare backstrap - no fire poking.

FN

Are you quite sure about that ?

Because that is exactly how I'd expect a carbon steel one to go. They start off super-shiney, just like stainless, but then patinate into a durable grey finish with blood, onion juice, vinegar etc, which is a good thing. How is the blade marked, i.e. show us a photo of the Mora markings on the blade showing the steel type. ?

 

[Fabnosh]

Ok, hands up, I got it wrong. Just looked and it is carbon steel (note to self, don't trust memory). As I've never got to the durable grey looking stage I had assumed (wrongly) it was the stainless version. If it is the blood, onion, vinegar etc then why wouldn't this have happened with the sheer volume of blood it's been covered with over that past few years?

FN

 

[sh1kar]

Guess after a gralloch you clean it very quickly but maybe just left it a bit after slicing the meat
S

 

[Fabnosh]

That's not a bad point. Experiment time methinks. I'll gently abrasively clean it to get back to bare metal and blood it and leave it and see what happen. Might be a few days but I'll report back. Every day is a school day.

FN

 

[sh1kar]

Check my post at no 7 re cleaning it

 

[Fabnosh]

Noted - thank you.

FN

 

[kripton]

I quite like the effect - looks as if you have found a quick and cheap way to "case harden" the blade - I would leave it or try to treat the rest of the blade similarly.

 

[bfltd0]

Definitely a Mora carbon steel blade. Exactly the same happened to mine after I chopped up some roe backstraps prior to putting them in the freezer.

Put the knife down for a while and got these pretty patterns!

On the stainless of course it would have washed straight off.

 

[Fabnosh]

Too late - already patented! I've re-colour hardened two purdey's and a Boss......and got to eat the backstraps as well lol. It'll need a sexy name in the hopes of grabbing the Creedmoor and Blaser gang so I've called it 'Blood Hardening' lol.

FN

 

[John_R]

I did a forced patina on one of my carbon Mora blades. After a through clean I just left the blade soking in white vinegar. I kept checking it to see how it looked, wiping with kitchen paper. Once it has got to a dark grey I washed it again, and it has remained easy to care for ever since,

 

[bfltd0]

Too late - already patented! I've re-colour hardened two purdey's and a Boss......and got to eat the backstraps as well lol. It'll need a sexy name in the hopes of grabbing the Creedmoor and Blaser gang so I've called it 'Blood Hardening' lol.

FN

You can have the patent.

I am going to advertise mine as "vintage" Mora with stunning and uniquely individual patina - starting bid £500...............