Designed as a science experiment of sorts, Terroir Hessen presented six 100% Riesling wines from vines of the same age, with the same range of acidity, same residual sugar levels, and held cellar variables constant. The single variable was the soil type that the vine was grown on. The focus was not necessarily on the soil's slope, but on its composition, though the two often are correlated, with slate being commonly found on steep slope conditions, etc. They also displayed soil samples, cross-sections of the soil types for a visual primer on the specific soils that were to be spotlighted in the tasting.
The German Terroir Tasting Results:
The Quartz Soil - The Rieslings produced on predominately quartz soil yielded very lean, highly aromatic, high acid, but low fruit wines. It is very hard for water and nutrients to penetrate the soil to any great depth and the vine's yield fewer grapes that also tend to be significantly smaller in size. Wines from some areas of the Middle Rhein are grown on straight quartz soil.
The Quartz and Loess Soil - The Rieslings grown on the combination of quartz and loess (a term meaning "loose" and comprised of silt, sand and clay combinations) soil allowed more fruit to develop as the loess allowed more water and nutrients to permeate the soil. Wines from the Rheingau region can exhibit the influence of the quartz/loess soil combination.
The Loess only Soil - The Rieslings from the Loess only soils made a wine that had a good bit of acidity, but also more fruit and more body. This wine started to see some semblance of balance. The Rheinhessen region can show characteristics of the loess soil type.
The Slate Soil - Rieslings grown on blue-gray slate soils tend to make a wine that is racy, lean and brimming with minerality both on the nose and the palate. The Mosel has its fair share of slate both in and covering its soil, with the slate doing its part to absorb the day's heat and release it back into the soil during the evening.
The Sandy Loess Soil - The wines from the sandy loess soil combinations were more delicate and more acidic with a bit less fruit present on the palate. The sand in the soil does not allow for the same amount of water retention as the loess only soil; the result is a leaner style of Riesling with a bit less body, noticeably less fruit, more acidity and a touch tarter overall. Wines from the small region of Hessiche Bergstrasse exhibit the sandy loess profile.
Clay Soil - This soil type is difficult for anything to grow well on, let alone vines. Clay soil makes for a tough environment for grapes to ripen, so the wines tend to be overly acidic and exceedlingly tart. They smell great, with impressive aromatics, but they often don't deliver on the palate.
Limestone Mixed with River Deposits Soils - The limestone soils that lay along the Main river, produce grapes that have been bathed in rich nutrients from bud break until harvest and yield wines that tend to show lovely aromatics, riper fruit, and a fuller body and better overall balance, provided that the given vingage had a growing season allowed for full ripening of the grapes.