I checked on the Riesling this past Sunday, three weeks after start of fermentation. The Winepod read a Brix of 8 and my hydrometer read close to 9. Last year, the Riesling was close to zero after three weeks. The difference could be a tighter control on temperature, since I set the targets further apart this time to prevent overshoot by the heater and cooler. The temperature has been a near steady 62 degrees from the start, whereas it drifted briefly up to 65 last year. The difference could be a slight increase in available sugar, but this is unlikely, because the starting Brix was within a degree or two of last years' starting point. The difference could be a higher level of SO2. I did not measure the amount of SO2 added by the vineyard, but I have no reason to suspect a spike this year. The difference could be the potassium bicarbonate added to reduce a higher starting acid in the grapes or the difference could be the higher acid itself.
Whatever the reason, I decided to add a little yeast nutrient and give the Riesling another week of primary fermentation in the Winepod. The taste is that of a sweet carbonated wine cooler.
I cracked open a bottle of the second cider lot on Monday. The added sweetness in this batch was nice, but at the moment I prefer the taste of the dry cider. The dry cider is especially good when drinking after having a few chocolates.
Thursday, November 5, 2009
On October 23-24, Alicia and I made a trip back to the vineyard at Keuka Lake to pick up this year's Riesling grape juice. We brought Maya along, our little Cairn terrier. It was raining most of the trip. The Finger Lakes received much less sun in the summer of 2009 as compared to 2008. The result is a lower available sugar content in the grapes and ridiculously high acidity. Tom, the owner of the vineyard treated the juice with potassium bicarbonate to drop the acid a little. He measured a starting Brix of 19.4 and a total acidity of 1.036. I purchased five pounds of dextrose to make up the sugar shortfall. When I later measured starting Brix after loading my juice into the Winepod, I came up with 20.4 -- somewhat better. Perhaps Tom took his measurement before the entire crop was crushed. Adding the 5 pounds of dextrose gave me a theoretical fermentation starting Brix of 23, although I could not take an exact measurement at the time with the sugar still dissolving in the tank. I calibrated the Winepod's Brix sensor at 23. After one week, the sensor showed 17, and my hydrometer measured 18. I have reasonable confidence that my Winepod sensor is accurate to within one degree of Brix. I plan to give the wine 3 weeks primary fermentation in the Winepod tank at 61-62 degrees F, the same as last year.
One of the new Riesling carboys, ready for fermentation in the Winepod. This year's crop is not nearly as oxidized as last year's. This means I will not have to work as hard to get the color right. It already has a superb golden color.