Most fly fishermen have heard of amadou, the fungus traditionally used to expel moisture from dry flies. Fewer have used it, and fewer still know where and how to go about getting hold of it in the wild.
The fungus from which amadou is extracted is Fomes fomentarius. It is a bracket type fungus and is found in birch woods across the highlands of Scotland. I’ve also found it occasionally on fallen beech trees. About the furthest south we’ve seen it is at the Lake of Menteith, though I know of one angler who collects his in Yorkshire. It kills the trees it infects, and so when looking for it, you should home in on any trees you spot through the woods that have lost their crown, and are but standing, rotting trunks. Fallen trees are also worth investigating. The fungus’s other names include horse’s hoof fungus, which is a perfect description. When hunting it, simply look for birch trees that have what looks exactly like a horse’s foot sticking out the side of the trunk. Another name for it is tinder fungus. It has a long history of use as tinder – it will catch and hold a spark and smoulder without flaming for many hours, allowing cavemen of old and woodsmen of today to carry fire from camp to camp.
A triple-decker lump of the source of amadou, the horse’s hoof fungus, Fomes fomentarius
The fungus is hardy and grows year on year. The size of the specimens therefore varies from a few cm across, up to rare giants of 30 cm or more. Experience has shown that the best quality amadou comes from young, fast growing specimens. The larger and older a specimen is, the more the unwanted spore tube mass (see diagram below) eats into the trama (amadou layer). In addition, the older a specimen is, the corkier and less pliable the amadou layer is. Therefore, younger specimens should be sought. The skin on older specimens is very hard and gives a clue to the softness of the amadou underneath. A quick test is to press the flat point of a pen-knife into the skin. If it goes in easily, it is worth investigating. If it is hard as steel, probably not.
The specimens below are growing on birch. The green colouration is due to algae growing on the skin.
Fomes fomentarius (amadou fungus)
Amadou can be confused with birch bracket. The inside of birch bracket (aka razor-strop fungus) is a uniform pale, soft to corky tissue. Tackle shops have been known to sell it as amadou. It might be good for sharpening cut-throat razors, but it’s not in the same league as amadou for drying flies.
Piptoporus betulinus (birch bracket)
We’ve also come across some stuff being sold as amadou that is just plain too uniform in structure to be real amadou — good copy though! Other imitations include the more obviously false ‘Shamadou’.
Finding where the amadou lay inside the lump of Fomes was trial and error the first time. The amadou forms a layer that is sandwiched between the hard outer skin and the spore tube mass (see diagram). The spore tubes makes up 60-90% of the bulk of the fruiting body and, along with the skin, need to be removed from the amadou layer and discarded . It needs set about with assorted coping saws, Stanley knives, chisels and power tools to separate the layers. The fungus does not yield-up its bounty without a fight and a few skinned knuckles!
The thickness and suppleness of the amadou layer is very variable. In the very best specimens, all one need do is get the amadou layer out and it’s good to go. However, about one specimen in 50 is that easy. In the majority of specimens we’ve collected, the amadou layer is variously very hard, very thin, very brittle, or all 3.
Steeping pieces in strong washing soda for a week is a basic approach. Boiling it for 12 hours is often recommended. There are other processes often recommended such as boiling it in urine or wood ash. We reckon this is only to aid its tinder properties and can be safely omitted for fly drying.
After soaking (and any boiling), rinse off all the water, which will have stained dark brown by now. Then, while the amadou is still soaking wet, beat it out with a mallet. This splays it out to more than twice its original area (and of course half its thickness). It makes it more spongy by breaking up the fibres, but at the risk of damaging the structure of the piece. The softer the parent material, the less soaking and hammering is required, and the less likely the damage. If, however, the original material was like a piece of wood (as many are), you may as well take the risk and go for it! The pieces must be allowed to dry slowly – this is key. If allowed to dry quickly, it will just go brick hard again. As it dries, give it a bend back and forth frequently to keep it supple.
A processed piece of amadou, ready for action
Having found a good bit of amadou, it should last you years, and it is worth the effort. The fact that you did it yourself will be appreciated every time you dry your fly with it. We reckon there’s nothing to beat amadou for getting a CDC that’s just caught a fish and is slimy and water-logged, back into action. Squeeze the fly between a folded piece of amadou to draw the water out, then back comb the fibres with the rougher side of the amadou. Dry as a bone!