Luke Lambert on sulphur and organic viticulture

Luke Lambert writes:

Sulphur use and fire taint in the previous vintage

The sulfur handling every year is zero for as long as I can push it till bottling. This was the case in 07. Everything goes to barrel with some solids/lees which buffers O2 and if there’s no substrate (sugar/malic) then I’m totally comfortable to mature wine without any sulfur.

A few weeks before bottling I start doing sulfur trials on the bench i.e. deliberately oxidising the wine to see how much free sulfur is necessary. I always bottle with lowest possible figure that the wine needs. i.e the wine dictates what’s needed, never a prescribed number.

As far as smoke this past vintage I’m waiting to see how the wines have handled it. It seems the valley floor was worst affected as the smoke settled there for longest. My shiraz vineyard has (fingers crossed) been unaffected but I’m going to hold wine in tank till late winter 2010 to see if the ashtray character appears. The latest research suggests that the smoke is imported through leaves and treated as a toxin by the vine then (cleverly) dumped into the fruit to rid itself of the problem. We kind of knew this pathway existed and in late February deliberately stalled photosynthesis to shut the vines down and limit pick-up.

I’ve sampled a lot of barrels across the valley in the last couple of months and there is definitely a significant taint issue but it seems everyone is realistic/pragmatic about it and not prepared to release affected wines as they know they will be heavily scrutinised. We’ll have to wait and see what eventuates....

Organic viticulture
While not certified organic both vineyards have been run with organic/biological farming principles for several years. Organic herbicides and under vine mowing has probably been the greatest leap forward. 5-6 years ago when glyphosate was used exclusively for weed control the soil was compacted and dead, in the last couple of years soil structure and the worms have returned, along with a bit of mulching the vines now seem a lot more tolerant of water stress which is a good thing given the run of hot vintages we’ve had!