Shalom’s vintage experience continues although bad weather has meant a halt to picking so he has had a few days off, hence not day 13 or 14 reoprt, but here’s day 15… in a wet and cold Austria
Day 15: Problems with a leaky tank 10/10/2011
It has been raining for the past 4 days. The temperature has dropped to seven degrees. I am wearing four layers underneath my shirt. What’s worse than the rain is the wind biting through my clothing. I can almost imagine what the bunches of grapes are experiencing as they hang on the vine.
I spent the last two days of the weekend resting from the hectic demands of the vintage. One day was spent in Vienna, which I regret to say wasn’t very fun due to the terrible weather. The following day was too cold to do anything so I just stayed in the house watching DVDs.
We had to drag ourselves out of bed even though all we wanted to do was sleep in. The day started for me by taking readings of alcohol and temperature. I was delighted to find 2 tanks have finished their ferment. It took 9 days for that to be done. The ferment was slow probably because of the low temperature ferment at 14 degrees Celsius.
We did some aeration of the tanks to let some oxygen get rid of the foul smells produced during ferment. At the same time, we had to watch the tank as we cycled the wines over the tank. When aerating the wines and pumping them over, the yeast tends to multiply in numbers and foam up the wine. Also, carbon gas is released causing the wines to bubble up over the chimney of the tank. We had to watch that the wine did not overflow out of the chimney.
We also continued pressing some of the newly brought in grapes. A lot of filtering and racking was done today. We had our first disaster today in which the tank was leaking and we lost quite a bit of wine. It was fortunate that this wasn’t the tank where the premium wines were in. We pumped the wines out of the leaking tank and discovered what the problem was. Tartaric crystals have crystallised on the door of the tank and even though the door was shut tight, the crystals created a small crevice. The problem was solved once we cleaned out the crystals.
My colleague and I were having a discussion about the quality of grapes when there is rain. The general principal is that when it rains, the berries swell up and expand in size. This causes a dilution of the sugars, acids and flavours in the berries due to the intake of water through the roots of the vines and the skin of the berries. Therefore, it is a big no-no to harvest the grapes when it rains. There are times when there isn’t much of a choice. When it rains, it can cause disease pressure and it is better to start picking the grapes before the grapes start rotting. Grape berries will expand and can burst, allowing disease to attack the berries easier. This happens less with grapes with thick skins as the berries have a greater capacity to expand. But with thin skin varieties, the tendency for the skins to burst is higher. Growers have to either pick the grapes or have nothing to make wine out of.
However, I have learned that sometimes rain isn’t always a bad thing. There are times when sugar levels in the wines are so high, it is better for the grape to soak up the water and the wine will be less alcoholic. Also, if the rain is not a lot, a little rain actually can help push up sugar levels in the berries. By waiting a day or two, one will surprisingly find that the grapes are higher in sugar than before the rain. I reasoned that this is probably because a little water and sunlight after the rain allows the grapes to produce more sugar through photosynthesis and that sugar production exceeds dilution of the berries. This all depends on which stage of the vintage does the rain set in. Right now, we are at a stage where the vines’ leaves are yellowing and photosynthesis is coming to a halt.