Coffee and Steel

[bigfootnampa]

So I’ve been roasting my own coffee for a while now.  I am no expert... but we’ve never had such terrific coffees!  I use a cast iron frying pan to roast my coffee.  I have noticed that this pan has developed a very dark and durable patina!  I clean the pan with hot water and scrub it with a piece of stainless steel chain mail after every use, as I clean my pans after cooking.  The patina persists and I wonder if it might be useful to treat smithy products with coffee?  Has anyone experimented with this?  I have not hitherto discovered a patina that seems as dark and durable as this one!  It certainly seems much more durable than any bluing that I am familiar with!

[Daswulf]

Care to let us in on the process? I'm curious. 

[Buzzkill]

I've used instant coffee to etch the pattern on a pattern welded blade.  I tested a piece after etching and the steel could be made bright again with high grit sandpaper in fairly short order - much like bluing.  The pattern was faint but still visible after the sanding back to bright steel.  You're probably getting a deeper etch effect, and with a different base material it might take the coffee finish better as well.

[bigfootnampa]

Daswulf; I just set my pan on an outdoor propane burner, pour in a heaping half cup of green beans and shake to level them.  Then I stir them until they are about the right colors.  I like my roasts a bit lighter than most... so when most of the beans are a nice tan color and about one third of them are dark coffee brown... I tip them into a stainless steel colander and shake them around a little.  I use a silicone spatula to stir with (this too has become permanently stained).  I usually roast around four such batches at a time.  The process creates a bit more smoke than you might want inside the house as a regular thing, hence the portable propane burner... outdoors.  The oils and smoke seem to create the patina.  I scrub pretty good with my chain mail scrubber... but the patina inside the pan is unblemished.  In this way I always have freshly roasted coffees at hand!  I usually grind enough for two to four days use at a time.  One advantage is that the green beans keep very well (up to a year at least).  I can order my beans off the Internet this way and still have fresh custom roasts.  I usually keep about three varieties in stock and change them up for different tastes.  The green beans usually sell for about $3 per pound less than the same beans roasted, but better flavor is my motivation.  I have been amazed to find that my own roasts are invariably superior to ANY that I have bought from any source!  I have considered buying a good roaster... but the terrific results I am getting make me reluctant to alter my process!  My roasts seem a bit more uneven in color than what I’ve bought pre-roasted.  I am not sure but what this may be part of my recipe for success!  BTW if you try this, keep a good BBQ glove handy to handle the pan with!

I wonder whether one might be able to devise a system combining the tempering of a blade with roasting beans to create a nice patina?  Perhaps a hook or similar item could be plunged into ground coffee while still at red heat?  At the moment this is just a hatchling of an idea.  I hope that some of my resourceful brethren of the forge, here, can help me develop it!

[Daswulf]

" Beans and Blades" Haha. Thanks for the explanation of the process. I have heard of people buying the beans unroasted since they last longer but never tried it myself. Sounds simple enough. I bought a smaller hand grinder and was grinding my own for a while. Then got lazy and started buying ground again. The thought of making my own dark roast sounds like a fun idea. And to patina a blade while doing it doubles the fun. 

Do you use a French press? I've found the flavor so much better using one. 

 

[BIGGUNDOCTOR]

Most say to grind just before using as they start to oxidize quickly.

How hot does the pan get?

Hmmm. make a container, place the blade in it, then pack ground coffee around it. Put in the oven and temper.

Do you have a picture of your pan?

I just started drinking coffee last year after a night at work when I could barely keep my eyes open. I am also looking to possibly open a small business and have picked up some commercial coffee makers for it; drip and a 2 group espresso. I used my French Press for cold brew which is supposed to release less acids than hot brewing. The little stove top espresso makers also are fun to play with.

[Frosty]

It's the oils and possibly the acids in coffee that's putting the finish on your steel. Cast iron is pretty porous and soaks up stuff like oil. The best cup of coffee I've ever had was at a little plantation  coffee stand on the Kona Coast. The owner said the fresher the roast the better the brew. He roasted out beans and ground them immediately then into the brewer still smoking. Oh BABY!!

The roaster he used was a small drum like a tumbler. It probably had a capacity of maybe 1/2 cup. It tilted directly into the grinder and the filter basket fit the grinder. Different filter baskets for different brews. The big roaster was in the next shed and was a pan maybe 6' around with a rotating wire that ran on the bottom like the old theater corn poppers. 

I had to carry a table and a three chairs out front so we could enjoy our coffee and the view. We'd caught him opening the stand, we hadn't gotten the idea of Hawaii time, 9:30 am is NOT normal opening time for a coffee shop, even at the hotel so we went looking. Anyway, we had our coffee and chatted with the old gentleman and when finished I asked for a couple to go cups and he said, "Stupid haoles,(yeah, I had to look that up) I'm not open go away!" That was that, he ran us off, wouldn't take money just wanted to get back to work.

Perhaps a drum roaster would work well for finishing blades though the tumbling might be a problem if the edge is too close to finished.

Frosty The Lucky. 

[bigfootnampa]

I have used French presses but I don’t like to.  I grind my coffees pretty coarse and brew with an old style percolator... a new model though.  

I recently bought some organic Kona coffee and it is terrific!  As good as Jamaican “Blue Mountain” at least!  This is better than any Kona coffee or blend that I’ve had before!  Absolutely NO bitterness at all!  

My pan... 10” diameter “Lodge” with 3” sides.  The higher sides help to keep the beans in when I get a little wild while stirring!

[lyuv]

This sounds like a very interesting finishing method to explore, and I intend to do so.

However, coffee roasting temperature is in the range of 190-250c (the oil smoke is at the higher end). Deep within the tempering zone. So it may be an issue with some steels and applications.

[billyO]

I realize I'm late to the game on this thread, but folks who do pattern welded blades have been using instant coffee to stain the carbon steel after etching for years, especially with kitchen knives.  It is NOT a durable finish, however and will rub off in time if care isn't taken.  The nice thing is that you can just soak the knife again when you want a greater contrast.  

It's my understanding, however that the cheaper the coffee the better.

On 5/26/2018 at 1:01 AM, bigfootnampa said:

I wonder whether one might be able to devise a system combining the tempering of a blade with roasting beans to create a nice patina?  

 I suppose this is possible, but the suggested tempering method for a 1080 steel for a kitchen knife is 400-450deg for two 2 hour tempering cycles.  And after putting all that work into forging, grinding and heat-treating a blade, why would you want to risk a faulty tempering?