Since arriving at the AWRI I have been intrigued by this term MOG, or Matter Other than Grapes. As I understand it, MOG is the extra matter that enters the winemaking process, primarily as a result of mechanical harvesting. Depending on what the MOG is, it can have a noticeable effect on the flavour of wine. My favourite so far is millipede taint – an unpleasant aroma caused by millipedes amongst the fruit.
Some of the anecdotal stories of documented MOG are quite absurd, and let’s face it, the name is funny too, but there is of course filtering processes that get this stuff out. And yet I was reminded of the ‘openness’ of the winemaking process after a very interesting tour through a McLaren Vale winery (thanks Simon). I was struck by how vulnerable the barrels full of ageing wine were to the outside. This does not mean that the barrels are open to things flying in, but that the only thing separating inside and outside of barrel is timber, and a timber plug or ‘bung’. The idea of storing things in timber all of a sudden seemed absurd when considered in the context of the food industry where control and sanitation is a high priority.
When I brought this up with the winemaker he explained that the wine’s high alcohol content creates an environment that is inhospitable to 98% of bacteria. Essentially the wine creates an environment that is hostile, killing the guests who dared to cross its threshold. This contradicts my view of wine as a symbol of hospitality, but explains winemakers ability to continue using traditional techniques such as timber barrels in winemaking.
The wine is hosted inside the body of the charred oak barrel, but the wine in turn hosts the flavour of the barrel in its own body. I am always intrigued when one material leaves a trace on another, when impressions occur through interactions*. This oak/wine relationship is so important that it is common practice to hang a stave (fragment of an oak barrel) inside industrial wine tanks to impart the flavour without the expense.
Oak characters, millipede taint, mousiness, smoke taint, or eucalyptus character, are host environment characteristics sublimated into wine adding un/desirable complexity.
* This is why the yeasts and their birth scars were so intriguing (week 2 and 3).