Sunday, 5 October 2014

The laboratory: where wine-changing decisions are made

Once cold, crisp morning, I turned up to work and was just gearing myself up to assist with loading the press, when I was told that I would need to help out in the laboratory. And not just for a few hours or for the day - for the rest of harvest!

Well, my first response was, "Sure. I am happy to help out, but you do realise I have absolutely no experience working in a wine lab?"
To this end, I was informed that the lab operations could be learnt but computer skills were harder to come by (I guess the thought process went that I'm an engineer so I must be ok on a computer).
And that was that...

Working in the lab is like working at the control centre of the cellar (at least it is at this winery). The lab is actually just a bench and some cupboards in the main office, which also houses the winemaker's desk and the general job desk where the work orders for all jobs in the cellar are prepared. So the Winemaker, Assistant Winemaker and Lead Cellarhand are in and out all day and I learn a lot about what is happenning and what decisions are being made, just from being in the room with them.

The best learning, however, comes from being able to monitor the maturity of the grapes, the progress of the ferments and the quality of the wine.

Preparing a sample of grape berries for analysis
At Road 13 Vineyards, they have definitely not scrimped on cost when it comes to lab equipment, despite the size of the winery.

Free Sulfur Monitoring
Daily sulfur checks are very important for freshly pressed juice that is being held in tanks for settling prior to fermentation. Small amounts of sulfur are added to each juice tank immediately after the grapes have been pressed to assist in minimising oxidation. Depending upon how long they remain settling in the tank, prior to being racked to a new tank for fermentation, it may be necessary to top up the sulfur. 

Instead of a drawn out process involving a series of test tubes and a Bunsen burner, which takes 10 minutes per sample, I have a titration machine which gives me the result in about 1 minute. Lucky me!

Sugar and Acid Content
Sugar content is measured in Brix in Canada, whereas it is Baume in Australia, which is a little confusing. I still prefer Baume as it is easily related to potential alcohol conent. Sugar content, pH and Total Acidity, are the defining figures required to assist a winemaker in deciding when to pick grapes. Of course they still need to make more subjective decisions based upon flavour development, which can only be determined by tasting out in the field, and there is no 'right or wrong' answer, it comes down to style, preference and experience.

Again, I am absolutely spoilt with a fancy machine to measure these factors using Infrared Spectroscopy Technology. At work, this expensive little box is called The FOSS (Named after Nils Foss, who founded a worldwide industrial analytics company). It is so easy to use! Basically, I pipette a few drops of the sample in question onto the receiving glass plate, close the lid and press start. There is some ticking and whirring for about a minute and then Voila, all the results pop up on the screen for me!

Fermentation Monitoring
The fermentation monitoring is a bit more hands on, with temperatures and sugar levels being measured using more traditional tools: a thermometer and hydrometer. I don't mind at all, as I get to go around and taste all the ferments each day to learn how they are progressing and start to understand how the flavours are developing as the sugar is converted to alcohol.

I must also check that there are no 'stressed ferments'. This can occur when the yeast are deprived of nitrogen, which is one of their essential nutrients. If this occurs, they can start producing Hydrogen Sulfide (stinky rotten egg gas) which can have a detrimental effect on wine quality. If this is detected in the early stages, it can be rectified by adding some DAP (Diammonium Phosphate) which contains the nitrogen they require. You just have to be careful not to add too much becauase if there is any remaining that the yeast do not use, it can become a fuel source for other unwanted bacteria.

Siphoning out ferment samples from the barrels

Although my lab experience is definitely not going to make me a titration guru, I am very lucky to be gaining such an invaluable insight into the decisions behind the wine production and the resulting styles.