Continuing from last week’s Bordeaux ~ You Can Bank On It ~ partie six…

This Earth Snapshot image is located on this Website: Sediments in the Gironde Estuary, France, and is of The Gironde Estuary, formed by the confluence of the Garonne and Dordogne rivers.

I left soil for last, because its a serious, geological contributor.  Studying geology takes a lot of time, has been my experience… There are so many layers; a natural pun, but so true.

Soil provides grape vines with nutrients, and it also regulates the amount of moisture delivered to the vines, or not delivered, in some cases. Interestingly, soil for viticulture is a paradox to soil for agriculture. For most agriculture, high nitrogen in the soil rules the roost. In viticulture, however, if the soil types have a lot of nitrogen, it will cause the grapevines to over produce. Wine grapes are traditionally tiny little berries. This gives a smaller ratio of skin to juice contact, and produces the intense flavors and tannins so important to making superlative wines.

 Bit of Bordeaux’s Soil History Until the seventeenth century, most of Bordeaux was swampy marshland. Then, Dutch engineers drained the waters, which revealed a rocky, gravel soil that is rich in minerals. This soil is perfect for growing wine grapes.

Left and Right Bank Variety Review

Like all other regions (e.g., last week’s Sonoma’s Russian River Valley the regions of Napa Valley in my prior post about Bordeaux), remember that soil in only one region can vary to a few different soil types. So, what I’m about to write is clearly board generalizations. I had one grower once tell me about five different soil types, all within his one vineyard. of which I could see all four corners. And yet, it was that diverse. So, think “generally speaking.”

  • When facing west in Bordeaux, looking toward the Atlantic Ocean, the “Left Bank” is south of the Garonne and Gironde rivers.
    • The wine must have at least 50 percent of Cabernet Sauvignon.
    • The other 50 percent must contain any variation of the following: Merlot, Malbec, Cabernet Franc, and/or Petit Verdot
  • When facing east in Bordeaux, the “Right Bank” is north of the Dordogne and Gironde Rivers.
    • The Right Bank wines are Merlot focused.
    • They also a good amount of Cab Franc, some Cab Sauvignon, Petite Verdot, and Malbec

Left Bank Soils

Cabernet is best suited to gravelly soils:

The level of earth is generally flat on Bordeaux’s Left Bank. It has a gravelly* top soil, which also has a layer of limestone bedrock. This stony top soil makes the each vine reach down deep for nutrients. In viticulture, this creates a desirable environment for old vines, as old vines create more tannins. It’s the tannins in a wine that makes the wines age longer.

Ah, we may be beginning to understand and/or appreciated Cabernet Sauvignon’s Left Bank plantings.

Gravelly* soils: This soil has excellent drainage, and is the type of soil that creates muscular wines with high extract of flavors and dense color.

In the early 1960s, I had neighboring farmer. He was 90s years young, and worked more than an acre of land each day, in a suburban setting. He also was my inspiration to just plant my first garden. I mentioned to him that I was watering my plants (this was in Maine, where rain is a norm). He told me to stop watering. If I gave my plants too much water, the roots wouldn’t go deeply into the earth to create strong plants. That fall, I created 36 quarts of tomatoes from not more than five or six plants.

The lesson if the soil has some gravel: don’t water if you don’t have to. Let the roots go deeply into the earth and create a strong plant.

Left Bank’s Most Famous Wine Regions 

An interesting note: all of the original chateaux from the start of the 1855 classification are on the Left Bank.

Right Bank Soils

Merlot is best suited to clay soil.

The level of earth is generally flat here, too. The exceptions are Cotes de Castillon and St. Emilion.

Gravelly soil is less predominant in the top soil of the Right Bank, where limestone is found at the surface level. clay soil dominates. There is an exception, though, in the Pomerol region. This is because of its location. Pomerol is at the tributary, where the Dordogne and the Gironde rivers meet. As a result, millions of tons of gravel have been dumped here, which has created a bed of sandy clay* deposits. This has formed into a layer of iron rich sands, so we’re back to age-worthiness of the wines.

Limestone* soil: This soil offers beneficial nutrients that make wine grapes grow better and they also produce sweeter grapes (hence the Sauternes). Limestone retains moisture in dry weather, but offers good drainage in cooler weather. While Limestone creates iron deficiency in grapes, viticulturist must frequently fertilize the soil.

Clay* soil: This soil type creates muscular wines with high extract of flavors and dense color, a key to Merlot’s character. Clay has good water retention, and therefore has poor drainage. The soil is high in acidity and is more cool than warm.  The Right Bank of Bordeaux is dominated by clay based soils

Right Bank’s Most Famous Wine Regions 


*Thank you Millesima CIE for the inspiration to learn more about Bordeaux this year. It’s working and I’m grateful for the lessons. Roots for me, which weren’t quite this understood.