FAQs

Spalting is any color in wood caused by a fungus.  Colors caused by trees as a host response are not spalting.  Examples of things people often THINK are spalting, but are NOT, include boxelder (Manitoba maple, Acer negundo), the green streaks in hard maple and basswood, the purple in lilac, etc.  Blue stained pine is spalting, as is ambrosia maple, as fungi cause the coloring, although they are vectored into the wood by insects.

Spalting is a product, not a fungus. Think of spalting like honey. When you go to the store to buy honey, you don’t usually want the hive (wood) or the bees (the fungus). Spalting is a secretion by wood decay fungi. Hence, the extracted pigments are indeed spalting, just like honey from bees is still honey, even when its not in the hive!

Different types of spalting look very different microscopically.  Below is a zone line in the transverse plane (cross section) of a maple. The melanin of the zone line crosses in a diagonal, filling the vessels, ray, and fibers with thick black melanin. Photo courtesy Dr. Daniela Tudor

All wood can decay, therefore all wood can spalt.  There are no ‘ideal’ woods for spalting, but all wood species spalt differently, and some fungi prefer some wood species to others.

Each different fungus takes a different amount of time to colonize different wood species.  There is no one answer for this, but, in general, if you are live inoculation, about 12 weeks. If you’re using extracted pigments, it’s just a few hours.

Every fungus is different! Some like it hot, some like it cool.

No.  Black lines (called ‘zone lines’) are just one tiny facet of the spalting universe.  White rot, the thing you get before you get zone lines, and pigmentation (think blue pine or green oak) are also spalting.  In fact, the oldest know use of spalted wood was the use of kurogaki in the 4th century Japan.

Spalting is caused by wood-decay fungi. Generally speaking, molds do not decay. Airborne molds are a very different type of fungus and are generally not responsible for spalting.

No.  Fungi are a kingdom, like animals are a kingdom. If you get bitten by a spider you don’t kill your neighbor’s dog. Just because two things are in the same kingdom doesn’t mean they are both dangerous. Wood decay fungi have no interest in you.

Yes and no.  If your already spalted piece is dry, there is nothing left to hop onto the new one.  If your spalted piece is still wet, in theory, it will work.  However note that if your spalted piece is ‘found’ spalted wood, or done without knowledge of which fungi you put on it, you have no idea what is on that spalted piece of wood, nor what else will hop off your spalted wood and onto your unspalted wood.  Spalted wood shavings, same deal.

Yes. Just get the moisture content back up to over 30% and have at it. The only thing you won’t be able to get this time around is blue stain.

Science.

No. Many woodworkers prefer to stabilize their spalted wood because it removes differences in density across the piece and can make turning/machining more uniform. It is certainly possible to woodwork spalted wood, even pieces crumbling in your hand, safely, without stabilizing. For woodturning in particular, this is a skill developed over time.

Yes, but you need to be more specific.  As of mid-2013 I’ve written over 100 articles on spalting, ranging from academic journal articles, to magazine articles, to books.  If you can identify which you would like sent to you, I will do so happily.

Yes!  But please e-mail me first and we can discuss what funding options are available, your background, etc.

Don Stephan very nicely did a comparative test for us of the different types of barley powders, and found that barley malt extract is ideal. Diastatic malt powder will also work. Pigmenting fungi prefer a honey media, with wild honey being preferred. Malt media is better for zone liners except for Xylaria polymorpha, which prefers PDA or YPG media.

We have run extensive testing on solid media versus liquid media, and every time, the liquid media performs poorly. We think this has to do with the higher ratio of nutrient to mycelia, and also the load. To be readily sprayed, liquid media is usually diluted with water, or is just dumped onto wood. First, this involves far more nutrient base than a standard agar plate, and second, the mycelial load is spread across the surface instead of concentrated in one area. For whatever reason, this greatly impacts the amount of spalting. As such, we recommend solid cultures only for inoculation.