David Coffaro Vineyard and Winery Winemaker's Diary
Week 3
January 17, 1999 to January 23, 1999 
January 17, 1999 

 I've done some more research on the Pinot Noir experiment. I've collected information from Ed Killian (winemaker at Chateau Souverain), and Grady Wann (the winemaker at Quivira), in addition to my mentor, Julian Iantosca, from Lambert Bridge Winery. I did confirm from my own tests, that the pH readings on the Pinots were correct. Even though all these Davis graduates gave me great information that I will relate another time on the Pinot experiment, they could not explain why the acid level on the hot fermentation should be so much higher than the others. I will ask a few more experts, but it appears that we must assume this will be another unresolved mystery of winemaking. 

January 18,1999 

We must talk further about the 1998 late harvest Sauvignon Blanc. The grapes were picked at 30.5 percent sugar. If these grapes had been fermented hot, with a very active yeast, they would probably produce a wine that is 17 percent alcohol and maybe 3 percent residual sugar. But I used a low active yeast in the hopes that I could stop the wine from fermenting at 8-10 percent alcohol and 14-16 percent sugar. When I racked last week, I suspected that it would be around 16 percent sugar at that time. Since last Thursday, even though I added 100 ppm SO2 and Bentonite to settle the wine, it has continued to ferment dramatically. Tomorrow I am devoting at least half the day to run the wine through a course filter to remove a good amount of the suspended yeast particles. I am hoping this will at least stablize the wine until I get Julia, my saviour, to lend me her sterile filterer to remove all the remaining suspended yeast cells so that we may bottle the wine in a stable condition. As most of you know, almost all white wines - especially dessert wines - are sterile filtered, and most red wines as well. As an amateur, I have made many dry white wines, none of which were filtered, and none of my commercial late harvest wines were sterile filtered. Some of you have felt that my late harvest sauvignon blancs have been some of my best efforts. I am starting to feel that maybe it is too much trouble to continue to make these. To buy my own equipment to sterile filter would cost another $5,000 and I am wondering if it is worth the investment. In a normal year, at an average price of $15 a half bottle, we have been able to gross about $10,000. This year, it should be only a couple thousand. This does not include the cost of bottles and the time involved in producing it. The cheapest filtering system out there is $5,000. Since I've decided to make a dry Sauvignon Blanc, I must decide whether I want to continue to make a late harvest Sauvignon Blanc, too. 

January 19, 1999 

Do you remember Caterino, Steve Ryan's smiling vineyard foreman? Well, I haven't mentioned that he has continued to come by within the last month to manage the pruning of my vineyard. He was here today to finish the last of the pruning, and it nostalgically reminded me that this was the time of year that I would be getting into high gear to begin pruning the vineyard myself in the past. As some of you know from 1979 to 1993, I pruned every vine in my vineyard myself. The vineyard consists of 20 acres, and I would start pruning as early as late October in some years, but would do very little until football season was over--after all, December and January are very cold months, even in Sonoma County. I know I haven't been posting temperatures lately (as we did during the harvest diary), but normally our average high is 55 with a low of 35. It is not unusual to have temperatures in the 20's, and last month we did get as low as 18 degrees. 

In the past, during February, March and part of April, I would prune as much as two acres a week. The temperatures during those months typically could range into the 70's, which meant I could prune in my normal attire--shorts and a tank top most of the time. Unfortunately, though, the problem we often encounter in these months is the possibility of  rain every other day - and since I would have accomplished very little of the pruning in November, December and January, I had to learn to endure the rain in order to finish pruning by bud break! 

I would have to say that pruning the whole vineyard by myself was the hardest physical work I've ever done. Most of the these days, especially in February and March when it might be pouring down rain, I believed there was no way that I would finish. But somehow, every year, I did finish although it was always in April and in some years the vines were already turning green as I was pruning the last few days. Carignan would always be pruned first because it is one of the first to bud out, and Cabernet would always be pruned last because it was the last.. I'm not sorry that I'm not pruning anymore. I do miss it but only because of the great satisfaction of reaching a goal that seems almost unobtainable by one human being, year after year. Until the last two years, I've been very dissatisfied with the pruning in the vineyard and had wished that I had the time to do it myself. But Caterino has given me great peace of mind these past two years. I have a great deal of confidence in him, and though I continually try to let him know what a great job he's doing, I don't think he really understands how important he is to me. 

January 20, 1999 

Two days ago, I talked about my latest experience with the late harvest Sauvignon Blanc. Not every year brings perfect conditions. Not every year can the wine be made successfully. I'm starting to realize that in the last 20 years, I have gained a lot of knowledge about producing this type of wine. In 1983, I made my first botrytis wine. That year, as in every year that followed, was unique. The grapes started rotting early and were ready to harvest in September at almost 100% botrytis. I produced an amateur wine that won a gold medal. I've  tried to duplicate that wine many times since. These grapes were harvested at 43 percent sugar, and I found that the fermenation would stop naturally at 14% alcohol and 14% sugar. Alcohol can tolerate only so much sugar. As the sugar rises above 30 percent, less alcohol is produced. At let's say 28 to 30 percent sugar at harvest time, alcohol can go as high as 17 percent, converting the sugar to almost zero. In theory alcohol is converted at a ratio of .58. In other words 20% sugar should convert to 11.6% alcohol. Each degree over 30, could leave approximately one percent sugar. I found last year since the sugar at harvest time was 55 percent, the wine was difficult to ferment. Thus, last year I ended up with a wine which was only 4 percent alcohol and over 40 percent residual sugar. The alcohol could not tolerate that much sugar and stopped naturally. I had to add some dry Sauvignon Blanc to reduce the sugar level to 31 percent and raise the alcohol level to 6 percent. As I said, every year is unique and I could go on to explain more about the ten times I have successfully made this wine, but it leads me to this year. 

Yesterday, as I promised, I ran the 1998 late harvest Sauvignon Blanc through a 7 micron filter. As I've said before, I have virtually no knowledge of filtering and I rely upon Julia. A 7 micron filter - from what all have told me - is very coarse. In other words, it lets through a lot of the wine and catches some suspended particles. These particles, from what I understand, are hopefully yeast cells. That will enable me to stop the fermentation on this wine. As I mentioned a couple of days ago, since the grapes were picked at 30 percent sugar, it will be hard to stop fermentation. I want to stop this fermentation "now" at 16% sugar and 8% alcohol. The filtering process was very unsatisfactory. It appeared that the coarse 7 micron filters got clogged up with less than 5 gallons of wine. Also, this filtering system - which only cost a few hundred dollars - is supposed to operate with a lot of waste. That is, it drips a lot! For me to pass 20 gallons of wine through these filters, another 6 or 7 gallons dripped into a pan. At the end of the day, I ended up with 15 gallons of filtered wine and 5 gallons of unfiltered wine. I was hoping that the fermentation had stopped on the 15 gallons, but I checked today and it was fermenting again. IT HAS A LIFE OF ITS OWN! Since my mentor, Julia, had no answer for this phenomenon, my next plan of attack is to go down to Santa Rosa tomorrow (also making my next run to Costco) to pick up *many* more filters. My hope of stopping this fermentation is rapidly fading. As a last resort, I plan to discard this wine and sterile filter only the previously mentioned "problem" 1997 late harvest SB. 


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