Pumice and Wine: A Tasty Mix

No matter your destination while you’re on Santorini, you’re bound to see at least one vineyard. Unless you know that Santorini is known for its wine, you might not be able to tell that these are grape plants at all. Due to the high winds on Santorini, the grape vines are grown using a technique called koulara. Koulara trains the grapes to grow in a circular fashion and stay low to the ground to avoid damage (1). The Minoan eruption, the most recent caldera forming eruption, deposited volcanic rocks, ash, and pumice all around the island of Santorini. Little did the violent volcano know that it would be providing Santorini with its distinct wine!

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Figure 1: Vineyard on Santorini

 

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Figure 2: If you look closely you can see the branches of the plant growing in a circular fashion or nest-like shape.

 

The Minoan Eruption:

Through learning how to do stratigraphic columns, we learned how to describe rocks. From going to different locations, we saw how the pumice was similar and how it was different. It helped to piece together the Minoan eruption. The Minoan eruption was the 4th caldera forming eruption on the island of Santorini. Some studies suggest that the catastrophic eruption took place in less than 24 hours! The eruption was characterized by five phases, all of which deposited pumice and ash of differing compositions.

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Figure 3: Pumice is an igneous rock that is light colored and high in silica content. It is also vesicular which allows grapes to grow

 

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Figure 4: Pumice layer on Santorini

Volcanoes erupt when gases are dissolved in the magma chamber. As the material is traveling up, the gases form bubbles. Afterwards, the rapid depressurization and expansion of gases produce the pumice and contribute to the vesicularity (sponge-like holes) of the pumice. This also contributes to the angularity of the pumice.

The pumice on Santorini is rhyodacitic, chemically composed of rhyolite which is from felsic lava and dacite which is from intermediate lava. The rhyodacitic pumice that fell was 400 degrees Celsius which causes a pink tint; however, it is the coldest pyroclastic material.

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Figure 5: The vesicularity of pumice is shown

Wine on Santorini:

Arriving in Santorini and leaving for field work, I was amazed at how much land was dedicated to wine grapes. It was interesting to find out that the grapes are able to grow in the deposits of the Minoan eruption. Pumice is key in growing the grapes here on Santorini.

Due to the Mediterranean climate of low rainfall and high humidity, the grapes are able to grow in the pumice and ash without significant rainfall! The vesicularity of the pumice allows it to retain humidity and allow the exchange of gases between the roots that give off carbon dioxide and intake oxygen (2). The vesicularity and the non-permeable composition of the pumice holds the humidity in order to provide the grapes with water. The grapes rely solely on the pumice retaining humidity to thrive. In addition, the pumice acts as a protection to the grapes because it doesn’t attract any insects that would harm the grapes.

The white wine grapes grown on Santorini consist of the Assyrtiko, Athiri, and Aidani grapes. Although Santorini primarily grows the white wine grapes, there are also Mandalieria and Mavrotragano which are red grapes. The popular wines include Santorini, Nykteri, and Vinsanto wine.

The Santorini wine is 75% Assyrtiko and 25% Athiri and/or Aidani. This dry wine has flavors of lemon and stone fruits. The Nykteri wine 75% Assyrtiko and 25% Athiri and Aidani. Unlike the Santorini wine, the Nykteri wine is harvested at night to avoid hot temperatures. Nykteri is a dry wine with flavors of citrus and stone fruits. The Vinsanto wine is 51% Assyrtiko and 49% Athiri, Aidani, as well as other small amounts of local white wine grapes. Vinsanto is a sweet dessert wine (3).

The Minoan eruption provided Santorini with a distinct taste in their wine. The Minoan eruption deposited about 80-90 km3 of tephra, which is fragmented volcanic material of any composition produced by an explosive eruption. The pumice that was deposited by the eruption lets the wine grapes thrive in the Mediterranean climate.

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After devastation came the gift of wine!

 

Sources:

  1. “Santorini (Wine).” Wikipedia, Wikimedia Foundation, 19 June 2018, en.wikipedia.org/wiki/Santorini_(wine).
  2. “Nature’s Footprint – Pumice Rock.” Nature’s Footprint, naturesfootprint.com/products/pumice-rock/.
  3. “Santorini (Wine).” Wikipedia, Wikimedia Foundation, 19 June 2018, en.wikipedia.org/wiki/Santorini_(wine).

2 thoughts on “Pumice and Wine: A Tasty Mix

  1. Laura,

    It is interesting how people have found a way to grow all sorts of fruits on Santorini, especially the grape. Your figures are well placed and provide images for the reader to understand the “geology language” you used.

  2. Interesting topic for your blog. I liked that you tied in how the geologic features affect the taste; in fact, I would have liked even further discussion of this. Nice use of graphics, though you do want to mention them in text (for example, “As figure 5 demonstrates, …).

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