Angel’s Share – a devilish solution to this unusual bacterial staining

On a recent trip to visit a firm in Stirling my hosts took me on a tour of the area – I’d been aware of “Angel’s Share” for a while but was quite unprepared for the extent of this soot-like deposit covering everything in the Woodlea Park area of Bonnybridge, trees, buildings, road signs, anything which allows spore development – coincidentally the area is home to at least nine Diageo whisky maturing bonded warehouses
If you do not live near a distillery, brewery or industrial bakery Angel’s Share (also known as Whisky Fungus) might be new to you.

Angel’s Share is the historic description distillers use to explain alcohol evaporation through wooden barrels, a natural occurrence of maturing, a barrel will lose around 2% volume every year – so, a 2% donation to the angels.

Angel’s Share is a fungus, Baudoinia compniacensis after Antonin Baudoin, a 19th-century French pharmacist and the first person to record the description of a black, sooty mould that grew near distilleries in the Cognac region of France.

Baudoinia is a sac fungus seen on a variety of substrates in the vicinity of distilleries, spirit maturation facilities, bonded warehouses, commercial bakeries and even fuel stations. Like many micro-organisms the fungus is a habitat colonist living in close association with other surface bacteria for the symbiotic mutual benefit of survival and reproduction. Angel’s Share has effused mycelium that can be velvety or crust-like and responsible for the phenomenon of 'Warehouse Staining'.

Baudoinia species use ethanol for carbon nutrition. Ethanol in vapour form, accelerates the growth of the fungus and stimulates spore germination. It’s ability to withstand high temperatures and therefore colonize habitats such as roofs, may be explained by the observation that ethanol vapour stimulates the formation of heat-protective proteins that prevent cells from being killed under these relatively extreme conditions in warm climates. Put another way Baudoinia thrives on airborne alcohol.

Baudoinia can thrive anywhere especially on outdoor surfaces subjected to daily temperature shifts, high relative humidity, periodic wetting - and ambient airborne ethanol. It can form on a vast range of substrates, tree bark, concrete, PVC plastic, galvanized roofing, render, masonry and stone.

Since the ethanol on which it feeds is denser than air, it doesn’t really float up into the sky toward the angel’s, but rather down into surrounding areas, making it the people’s share.

When the airborne ethanol meets even the smallest amount of moisture - and distilleries are usually near a water source—you get Whisky fungus all over the place. The closer to the bond warehouse or distillery, the thicker the fungus and more of it.

Many solutions exist to treat the symptoms, bleaching will do as it says – but at what cost to the environment and buildings, sodium hypochlorite is an oxidiser so should only ever be used with caution.

To treat the cause the only sustainable and biodegradable choice is a Quaternary Ammonium “food grade” DDAC (Didecyldimethylammonium chloride). DDAC’s come in food or industrial grades. Food grade is high purity with nothing added. Industrial grades are achieved through an extraction process which usually involves the addition of ethanol – would you give beer to an alcoholic?

The benefits of high purity “Quats” have been used in healthcare as a cleaner and disinfectant for over a century. Fortunately we have one – GK Pro the leading professional treatment for building and amenity cleaning, a high purity DDAC is the only product recommended by most render system manufacturers.

Like a magnet is attracted to metal our biocide is attracted to algae, fungi and other bacteria. It kills at the cellular level through cationic action – in the process exhausting itself, the act of depleting itself making it environmentally biodegradable.

Although as simple as a window cleaning programme and not disruptive to building occupants, the treatment should be undertaken by professional cleaners, trained in application methods