Spalters Inc. #11: Progress on the green elf cup's pigment

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Blog entry by Sodabowski posted 11-14-2014 12:09 AM 2789 reads 0 times favorited 6 comments Add to Favorites Watch
« Part 10: Predashun: I haz it Part 11 of Spalters Inc. series Part 12: Essential reading: upcoming book from the scientific authority! »

Hi Jocks,

Working on and off on that fungus still. There’s been considerable progress on the US side since the team led by Dr Spalting nailed down the conditions into which Chlorociboria produces xylindein. Not that I didn’t send a hint or two ;)

Since they did the huge work that was needed to understand how this fungus works and how to tame it, I’m the happy bunny who’s now tinkering with the pigment’s chemical part. Not that I’m a chemist, nananaw, but since I’m in a mixed Masters course now, I study both physics and chemistry (to become a college and high school teacher of both). Which gives me many possibilities to access the chem lab hardware, and most importantly, the experts.

Digging on my own side of the ocean I had one of those “whack own’s forehead” moments a few days ago, and made quick tests to check out the reality. Bullseye: xylindein changes color with pH. So my spectra are good to dump and I must do them again. Actually, xylindein is a weak diacid (it can give off two hydrogen atoms per molecule), so it has THREE different colors depending on the pH, and what I took for decay when heated was one of the color changes, which can be reversed in some cases (I’ll study that in deep later this year).

So today I set up a side experiment at the lab and made a pre-wash with ethanol to a very decently saturated sample in sawdust and shaving forms (remember, there is no such thing as scrap wood!). Ethanol washes out the tannins in wood (that’s true for almost all woods) but not xylindein. Not as much as acetone anyway. As my tests confirmed (more on that later next week) ethanol washes out the tannins, which also have color dependency upon pH, but very little xylindein if any at all. So today was laundry day, and I got my sample cleaned up in preparation for the actual extraction.

Cue the Soxhlet apparatus, which is a genius’ work. Let me explain how it works.
There is a round flask at the bottom, attached to the Soxhlet apparatus. Said flask is heated by the blue thingie. Inside the Soxhlet you can see a kinda white-ish cylinder of sorts: that’s the filter cartridge inside of which the sample is located. The Soxhlet is then filled up with the solvent, almost to the top of the little glass tube that can be seen at the left. The round flask also gets its share of solvent (I used a small one, way too small actually). Then a water-circulating condenser is fitted above the Soxhlet and, well, connected to the tap to have cold water circulating inside.

While heating, the solvent evaporates and travels to the top via the glass tube to the right. It rises up to the condenser, where it cools down, liquifies and drips down into the cartridge. This is pure recondensed solvent, whatever it contained stays inside the round flask at the bottom. Now this is where the magic happens: while the solvent drips down, its level rises inside the Soxhlet. Remember the little tube at the left? That’s a siphon. As soon as the solvent level reaches the top of said siphon, WOOSH, gravity takes its duty and everything is sucked down into the round flask, and since this is the solvent that went through the sample, it’s loaded with whatever soluble compound is inside the sample. Once all the solvent has been sucked down, the siphoning action stops, the level of liquid inside the Soxhlet starts to rise slowly again, and so on.
No moving parts. No pumps. Only freaking hydrodynamics and gravity. Really clever stuff.

I hope these explanations were simple enough, I also filmed the siphoning action, which happened every twenty minutes (slow, because of the very small round flask, I’ll aim for a big one next time).

Check that out:

More after the exams… Cheers from the lab.

-- Thomas - there are no problems, there are only solutions.

6 comments so far

View shipwright's profile


8816 posts in 4256 days

#1 posted 11-14-2014 04:00 AM

Interesting, Thomas. I’m going to buy myself a glass of wine because I actually understood over half of that.
Two questions arise:
Is “blue thingie” a scientific term that is only used in France? (If so I guess it is likely ” chosie bleu” and you have kindly translated it for us)
When do we get to use the dye to get green veneer?

Oh, and a third question, you mention tannins being pH sensitive with respect to color. Is this involved in its blackening when exposed to ferrous ions? Is there a pH related sub-reaction involved there somewhere or is this another phenomenon altogether?

-- Paul M ..............the early bird may get the worm but it’s the second mouse that gets the cheese!

View Sodabowski's profile


2404 posts in 4291 days

#2 posted 11-14-2014 09:41 AM

Hi Paul, the “blue thingie” was my late night term for “round flask heater” actually ;)

The dye itself wouldn’t work as good as the fungus itself, since it would give similar results to staining wood with any pigment: flooded, no selective inking, color everywhere. The interesting thing with spalting is that only the parts of the wood into which the fungus can actually go get some color (namely the sap channels if I understood well). Thus there’s a lot more depth and variation to it. If the idea was to artificially flood wood with a pigment to stain it, the easiest and cheapest way would be solid pigments like indigo and a yellow one, or even printer inks. But never can you get such a result.

Now the ferrous ions. These aren’t alone, there is a pH zone into which they exist (raise the pH and they precipitate out of solution as an hydroxyde, so yes, you’ve got them in acidic conditions). So yes, you got it, there is a relationship :) You can get similar results with ammonia (even in its fume form) with, say, oak, only than this time it’s the other way, since ammonia is basic (raises the pH instead of lower ing it for acids). Might be interesting to set up a small experiment now that you bring the subject out. I’ll keep it in my to-do list and keep you guys posted on the matter :)

-- Thomas - there are no problems, there are only solutions.

View Schwieb's profile


1925 posts in 4919 days

#3 posted 11-14-2014 10:42 AM

Hi Thomas, Unlike Paul, I’m not sure how much of that I understood, but I had a glass of wine to cheer you on. That’s quite a device. I was always fascinated by the glassware used in chemistry labs. Interesting to watch how this one works. Great to see a post from you, keep up the great work.

-- Dr. Ken, Florida - Durch harte arbeit werden Träume wahr.

View Blackie_'s profile


4883 posts in 3970 days

#4 posted 11-14-2014 02:20 PM

Ok let me take a crack at it to see if I’m even close, the reason I am curious in this blog is because I am a Spalter and have a corner pit in the back yard with logs cooking now, though I think the winter is going to slow things down a bit, also in my adventures I’ve found that some species spalt faster then others.

Is this test to see how colors are formed when spalling?

-- Randy - If I'm not on LJ's then I'm making Saw Dust. Please feel free to visit my store location at

View Sodabowski's profile


2404 posts in 4291 days

#5 posted 11-14-2014 03:31 PM

No Randy, not exactly. I’m researching on the pigment itself, not the fungus (which has been intensely studied already). My aim here is to determine the limits of the woodworking techniques that can be applied to the wood stained green by Chlorociboria without losing its unique color.

Depending on the wood species AND (most importantly) the fungi type, spalting can be lightning fast (well, weeks) or snaily slow (years). Did you check out Dr Spalting's series on the Fine Woodworking website? First place to look at :)

-- Thomas - there are no problems, there are only solutions.

View Blackie_'s profile


4883 posts in 3970 days

#6 posted 11-22-2014 12:16 AM

Oh ok thanks for the info on the link I’ll check it out.

-- Randy - If I'm not on LJ's then I'm making Saw Dust. Please feel free to visit my store location at

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