Confusion Corner: Tuff, Tufa, Tuffeau
November 28, 2019 5 Comments

Tuff, tufa, tuffeau: welcome to confusion corner.
These “three t’s” are all types of stone and/or soil. Two—tuff and tuffeau—are of particular interest to viticulture, while tufa is the odd man out.
Let’s take a closer look:
Tuff: Tuff (pronounced tuhf like the English word tough) is a type of volcanic soil; however, it is sometimes classified as a sedimentary soil—so let’s just say it is formed via both volcanism and sedimentation.
Tuff is created in several stages: first, molten lava blasts out of a volcano. Second, this lava cools and fragments as it floats through the air and (third), it eventually lands in a heap upon the ground. With time, these fragments—which include volcanic ash and bits of igneous rock—settle, condense, and cement together into a soft, porous stone.

Tuff-based soils are found in Napa (Howell Mountain), Lake County (California), Madeira, Hungary (Tokaj), Alto Piemonte (Gattinara, Ghemme), Campania (Mount Vesuvius) and large swaths of Yellowstone Park.
Tuffeau: Tuffeau (pronounced too’-foo) is a specific type of limestone found in the Loire Valley. Tuffeau is fine-grained and very low density (about half the density of granite). Tuffeau is formed from the remnants of the sea floor (sediment, fossilized sea creatures, and sand) that covered the Loire Valley over 90 million years ago. Over the millennia, these particles became compressed to form a unique type of limestone. Tuffeau’s uniqueness is due to the presence of foraminifera (creatures with multi-chambered shells), and the (previously) shallow water that stood between 2 and 20 meters deep. Most other forms of limestone are formed under deeper waters.

Weathered tuffeau, combined with sand, flint, and clay—as found in the Central Loire regions of Anjou, Saumur, Touraine—is an excellent vineyard soil. Tuffeau—also be known as Turonian Limestone (after the city of Tours)—is also famous as the building blocks of many of the gorgeous castles of the Loire.
Tufa: The words “tufa” (pronounced too’-fah) and “tuff” and commonly confused, and that’s ok for people having casual conversations about the ground beneath their feet. However, for geologists and wine geeks, there’s a big difference between the two. So here goes: tufa is a rare type of limestone created when calcium carbonate-saturated water releases carbon dioxide and precipitates a soft, calcium carbonate-based rock. Tufa is specifically formed in ambient-temperature water.
The best-known examples of tufa (in the fascinating form of tufa towers) can be found at Mono Lake, California. Tufa is not—to the best of my knowledge—a factor in vineyard soils.
Tufa deposits originating from hot springs are known as travertine—and that’s a whole other corner story.
References/for more information:
- Feiring, Alice (2017) The Dirty Guide to Wine. New York: The Countryman Press.
- Franzmeier, Donald, William McFee, John Graveel, and Helmut Kohnke (2016). Soil Science Simplified, 5th edition. Long Grove, Illinois: Waveland Press.
- Robinson, Jancis and Julia Harding: The Oxford Companion to Wine, 4th Edition. Oxford, 2015: The Oxford University Press.
- USDA Soil Survey/National Resources Conservation Service: http://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/survey/
- Soil Science Society of America: https://www.soils.org/
- https://www.monolake.org/about/geotufa
- https://www.britannica.com/science/tuff
The Bubbly Professor is “Miss Jane” Nickles of Austin, Texas… missjane@prodigy.net
Thanks Miss Jane. A very useful clarification of terms which certainly tripped me up on many occasions. Is it worth mentioning a fourth ‘t’ word – travertine? Different from Tufa in that it forms in warm water (by the same precipitation process you describe for Tufa), but as water temperature increases so the volume of calcium carbonate that can be held in suspension increases leading to larger deposits of travertine. Unlike Tufa, travertine does factor in vineyard soils such as the Tuscan DOCs of Bianco di Pitigliano and Orcia.
Ref: Maltman, Alex (2018) Vineyards, Rocks, & Soils. Oxford University Press.
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Soil in Muenchberg Grand Cru in Alsace is rich in tufa
I live in Alsace, and the soil here is rich in compacted volcanic ash…tuff….but we are hundreds of miles away from Tufa (created under water).