Two Napa Valley Winery Tours

Quote of the Day

The emotion at the point of technical breakthrough is better than wine, women and song put together.

- Richard Hamming


Figure 1: Wine Graphs are Different than Table Grapes.

Figure 1: Wine Graphs are Different than Table Grapes (Source).

I am on a business trip this week to Petaluma, California, and for the first time in my career I brought my wife with me. She has never been to California and this seemed like a good time to leave Minnesota -- it has been a tough winter.

While I do not drink, my wife does and although her favourite wine is a Shiraz and she swears by the qantas wine guide on shiraz when choosing her next bottle as we were going to be in Napa she wanted to tour some wineries in the Napa area and we chose to tour two wineries, Cakebread Cellars and Joseph Phelps Vineyards. We chose these sites based on the recommendation of one of the engineers in my group. Both sites were impressive and we had a very enjoyable time. At Cakebread Cellars, we had a 90 minute facility tour and wine tasting, while at the Phelps Vineyard we took a 90 minute class on wine barrels, and I learned that the wine barrel is a very important part of the wine-making process. In fact, it actually inspired me to learn more about the brewing industry when I got back from the tour. I know a friend who makes wine herself using wine barrels and it tastes delicious. I wish I had the time to brew some wine myself but I'm a busy person!

I thought I would review some of the things we learned about wine on the visit. On a previous trip (~10 years ago), I had visited the Mondavi winery and I was very impressed with the attention to detail shown at that winery. On this trip, both of the wineries we visited discussed the important role that Robert Mondavi played in establishing Napa as a wine-making region -- he was described as a marketing genius by the folks at the Phelps Vineyard. I found it very interesting that he was originally from Hibbing, Minnesota. I have a cabin near there.

As a side note, we met Jeff Corwin (television travel and animal expert) and his wife Natasha at the Phelps Vineyards. They were taking the same class my wife and I were. He was quite the wine connoisseur. There were also some folks from a high-end fishing lodge in Alaska taking the class. It sounded like their clientele is very into wine and they were on a buying trip. I know my wife would have loved it if we had brought wine home with us, she had even made me look at IWA's wine luggage cases, but I told her no. Maybe the next time we go I might consider it, but it would just be too much to handle this time around.

Wine Basics

Wine Growing Regions in the Napa Valley

Figure 2 shows the main wine growing regions in Napa.

Figure Y:: Different Wine Growing Regions in the Napa Valley.

Figure 2: Different Wine Growing Regions in the Napa Valley.

It was interesting to hear people discuss the unique characteristics of each region. For example, people raved about the grapes from the Stags Leap district. Apparently, the soil of this region is composed of eroded volcanic material from the Vaca mountains. Soil with volcanic origins appeared to be highly prized.

The Grapes

The grape vines were mounted on frames using a technique called espalier (Figure 3). This approach makes it easier to manage the grape vines. We saw many acres of grape vines in Napa with many different forms of espalier.

Figure 1: Grape Vines at Cakebread Cellars.

Figure 3: Grape Vines.

Figure 4 shows how the grape vines are managed on a massive scale.

Figure 2: Example of a Field of Grape Vines.

Figure 4: Example of a Field of Grape Vines.

We were also shown how they prune the grape vines. Here is a good video on the process.

The Wine Label and Appellations

I had no idea that the wine label was such a big deal. There is a definite structure to the label. We spent a fair amount of time discussing the meaning of the various terms on the labels for the bottles and wine barrels. For example:

  • To put the name "Napa" on the label (called an "appelation"), the 85 % of the grapes used to make the wine must come from the Napa region.
  • For a California appellation, 100 % of the grapes must come from California.
  • For a county appellation, 75 % of the grapes used must be from that county.

While I won't go into the details here, there are also definitions of all the various types of wines. For example, a wine must be composed of at least 75 % Cabernet Sauvignon grapes in order to be called a Cabernet Sauvignon wine.

The appellations are so important that they are controlled by an industry association called the Meritage Alliance, which is focused on the US wine industry but is growing an international following. If you want to look up more information on appellations, see this web site.


The wine industry is very concerned about being viewed as "green". To that end, each of the vineyards were visited talked about biodynamic agriculture, but they did not claim certification. There is an international association called Demeter International that certifies conformance with the biodynamic approach to agriculture, but apparently it is a very strict system that is expensive to follow.

Making Wine Barrels

At Phelps Vineyard, we watched a video on how wine barrels are made at the Nadlie Cooperage in Napa. Here is a similar video that is on Youtube.

Phelps's barrel class covered quite a bit of the history of wine barrels. Here is some wine barrel trivia:

  • The wine barrel has a noticeable effect on the taste of the wine

    We tasted wine from barrels made with French Oak and American Oak. There was a noticeable difference in taste.

  • The toasting of the wine barrel made a big difference in taste

    We sniffed 12 different levels of toasting. They were distinctly different in scent. We also tasted four wines from different barrels of different wood (French Oak versus American Oak) and different levels of toasting (medium and heavy). They had distinctly differently tastes.

  • King Louis XIV of France is a venerated figure in barrel making.
  • Barrels can be used up to 4 times for making wine.

    After four times, the tannins in the oak are effectively leached out. Their use of the barrel for four vintages is consistent with the Wikipedia statement that a barrel may be used for three to five vintages. As you would expect, new barrels have a bigger effect on taste than used barrels. The used barrels are recently finding value in beer brewing.

I am so impressed with the vision of Louis XIV. Here is a quote of his from 1662.

I will apply myself from this year henceforth to the management of the forests of my realm, in which disorder is extreme.

His key action was the appointment of Jean-Baptiste Colbert in 1661 as the administrator of the forests. Colbert instituted a forest management plan over an eight year period that has given France an excellent source of oak that exists to this day.

Grape and Wine Productivity Information

A number of grape and wine productivity measures were quoted during the tours:

  • 150 gallons of wine per ton of grapes.
  • about 750 bottles of wine for every ton of grapes (assumes 750 mL bottles)

    Knowing that we get 150 gallons of wine from each ton of grapes and there are 750 mL in a bottle, we can compute number of bottles per ton as follows:

    {{N}_{\text{BottlesPerAcre}}}=\frac{150\frac{\text{gal}}{\text{acre}}\cdot 3.785\frac{\text{L}}{\text{gal}}}{750\frac{\text{mL}}{\text{bottle}}}=757\frac{\text{bottles}}{\text{ton}}.
  • An average of 4 tons of grapes per acre.

    This is an average value ? the range is reported to be between 1 and 30 tons per acre.

They were consistent in their use of these numbers. Our guide commented that black bears eat 2 tons of grapes per year from one of their mountain vineyards. At another point, she stated that 1500 bottles of wine every year are lost to bears at that vineyard.

Cakebread Cellars has over 400 acres planted. Here is a quote from their web site:

The first 22 acre parcel was purchased in 1972. Over the years, the family has continued to acquire additional vineyard parcels throughout Napa Valley and the North Coast. Today, the winery owns 13 sites totaling 982 acres, 460 of which are currently planted.

Knowing the acreage, grape yield, and conversion factor from grape tonnage to wine, we can estimate the total wine bottle production from this operation (Figure 5).

Figure 3: Per Acre and Total WIne Bottle Production Estimate.

Figure 5: Per Acre and Total Wine Bottle Production Estimate.

In case you want another viewpoint on these calculations, I found a blog by a vineyard in Australia that comes up with similar numbers in different units (e.g. liters instead of gallons, etc).


Both vineyards kept beehives on their properties. They commented that the grapes vines are self-pollinating, so the bees were not needed for their wine operations. However, both vineyards had other crops on their properties and they wanted the bees there to pollinate those crops. These other crops were to support the fresh food needs of the cooking classes being conducted there. The vineyards are working to combine their wine operations with healthy lifestyle courses for their customers.

Label Descriptions of Toasting

Table 1 shows information on the meaning of the toasting level markings on a wine barrel. These descriptions are from a handout given during the class at the Phelps Vineyard. The handout was written by the Sequin Moreau Napa Cooperage.

Table 1: Toasting Level Information.

Toast Level





Light Toast


Earthy milder wood characters, complex backed aromas begin to develop.

Reduced vanilla component as toasty, fresh flavors begin to develop.

Wines which require a minimum of aroma enhancement, but will benefit from increased tannins

Medium Toast


Complex, toasty aromas, vanillin, coffee and freshly baked bread.

Round, sweet oak flavors, complex toasted notes: spicy, butterscotch, vanilla caramel and chocolate.

Ideal for most red wines. Balanced interaction of toasted aromas and structural support.

Medium Long

(Burgundy Style)


Hazelnut and spice with more minerality and delicate oakiness.

Soft structure with smoother tannin profile, due to slower and more controlled release of oak characteristics.

Wine not requiring significant tannin contribution, for wines requiring barrel aging and maturation character

Medium Plus


Vanilla bean, hazelnut, spice, oak lactone diminished, slight acidity with an expresso note.

Greater depth of toast brings rich and round flavors: intense vanilla bean, chocolate mocha, spice, integrated oak tannins.

Useful for fuller flavored wines. Use where wine has richness of its own and can accept a full but balanced impact of oak on both the nose and palate.



Smoke characters, touch of black pepper, oak lactone diminished, slight acidity with expresso note.

Smokey, roasted coffee, some bitterness with a reduction in sweet roasted flavors.

Best for full impact of complex aromas. Lesser contribution of tannins to wine structure.

Toasted Heads


Reduces oak lactone and dusty wood characters, more even pickup of toast.

Lessens structural contribution of oak tannins and contributes an increase in the toast characteristics

Works well for medium weight white wines. Also useful in reds which have sufficient tannic weight and allows for more consistent characters.

While I copied this from a handout, I eventually did find a web reference.


It was very nice to have my wife with me on a business trip. It was the first time in 35 years and long overdue.

I do want to comment on the wine industry's combination of science and mysticism. One of the vineyards commented that they hire a sheepherder to graze his flock on their property because they want to keep the grass cut and the manure generated by the sheep is good for the grapes. They then commented that they buy cow horns from a ranch in Montana and mix that in with the manure. They let the mixture sit until the cow horns have disintegrated, at which time they spread the manure. As a person who has spent his share of time around manure, I have never seen anyone do this. They commented that other growers think that the horns make no difference, but they still continue to do it. As I understand it, they have no evidence to support what they are doing, but they are going to keep doing it. It seems almost to be a ritualistic behavior -- why Montana cow horns? Are they special somehow? Apparently, this horn worship is part of the biodynamic movement.

Maybe it is like the superstitions people have where they feel they need to where the same underwear or socks whenever they watch their favorite team play.

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