Introducing, Dr. Loosen! … A well known winemaking estate in the Mosel region of Germany, they specialize in Rieslings of varying styles and qualities.

Conveniently, Dr. Loosen himself has supplied the good people of the wine-drinking world with a compact guide to each wine that is produced. Here is the guide for the 2018 vintage of the Graacher Himmelreich Riesling. 

The 2017 that we will be enjoying today is of course a year older. However, the alcohol being the same between years, and the style remaining consistent as you would expect from an identically labeled bottle from a century old winery, I think we can assume we are pretty close with the metrics and practices. Therefore, without being too pedantic, what we have here for reference may serve as a great preface for what’s to come!

One of our favorite sommeliers, Aldo Sohm, noted this wine to be an “incredibly sophisticated, nuanced, and layered Riesling” which is also “flexible food”. This is also a GG wine, which stands for Grosses Gewächs (GG), meaning “great growth” in German, and is a reserved designation for a highest quality dry wine coming from a Grosse Lage, or the German equivalent of grand cru vineyard. 

Germany is, for all intents and purposes in the winegrowing world, a cold climate region. Winemaking regions around the globe typically lie within the 30th and 50th degree of latitude in either hemisphere. Mosel is rocketing in at around 50°N, 7°E on the radar which means (at 200,000 ft perspective) there are usually issues achieving full ripening toward the end of the growing season leading up to the harvest. As it goes, a large component of the quality metric for German wines has developed to include a healthy abundance of residual sugar (RS) with higher acidity to compliment (depending on style); two variables with an inverse relationship as the growing season progresses, but ever so complementary in the glass! 

Sugar content in German wines may vary depending on the intended category for sale (listed dry to sweet: trocken, halbtrocken, feinherb, restsüß, and edelsüß). This categorization is furthermore influenced depending on the acid level present in each wine, but we’ll leave it at that.  The point here is that German wines can often be experienced to be on a different scale of RS versus what the majority of the world calls, dry, off-dry, sweet, dessert wine, etc. 

Most of the world uses a scale known as degree brix (brix°), or percent soluble solids present in a solution at standard temperature and pressure via hydrometer or refractometer, which ultimately measures sugar content and even gets down to negative values once ethanol concentrations reach the point where the wine’s density becomes less than that of the standard, water. Germany uses the oeschel scale (°Oe), where one °Oe is equal to the gram difference in mass versus the universal standard. In the United States, bone-dry will typically be observed in the -brix° range (<1 g/L RS), dry to off-dry around 1-2 brix° (1-20 g/L RS), and a range of sweetness depending on appertief, late harvest, or fortified wines which may get up in the 5-10+ brix° range (50 - 100 g/L RS). Our Riesling we have here, labeled “dry,” comes in at 8.7 g/L RS, a deceptively described wine versus what we’re used to. However, with such high total acid (7.8 g/L TA), it will be interesting to see where we rank the sweetness. Typical acid levels in white wines from California tend to be more around 3.0 - 3.7 g/L TA. 

We are hoping to get some great aromatics from this wine. The acid and sweetness interplay will be one interesting aspect, but often Rieslings are known for exceptional stone fruit and floral qualities. For the time this wine spent in barrel undergoing sur lie (as noted in the guide above), we are looking for a nuanced mouthfeel to interplay with the acid, perhaps with some honey on the palate. High hopes are also in place for some good fusel alcohols, or higher alcohols, which they are commonly referred to as, and TDN (1,1,6,-trimethyl-1,2-dihydronaphthalene). The vastly different styles being apparent between a California and German Riesling, a Riesling grape often doesn’t disappoint as long as sugar and acid are in check. We're excited to crack this one open!

Futher notes:

However sweet this wine was, it was balanced by the high acid at 7.8 g/L. Quite high acid indeed! 

The highlight was the mouthfeel and crispness generated by the effervescence and acidity in this one. There were, however, less impressive aromatics and overall we felt they were lacking, and more difficult to pick out. Common perception by our palates has it so sweetness and acidity counteract each other, allowing for the sum of the two to provide great mouthfeel, slight astringency by the higher acid, and a slight increased density and viscosity to aid in a prolonged finish. We were not so successful in picking out the influence of sur lie in this one, although it may be melded with those qualities mentioned above to go seemingly unnoticed.

Furthermore, judging by the level of acid intensity, and the noticeable “green” quality, there’s good confidence in estimating a relatively high proportion of malic acid present in this wine. If you’re unfamiliar with malic acid, go have yourself some sourgrass! Stems of those little yellow flowers growing in the cracks of sidewalks are full of them! 

The decision to finish the wine with some effervescence was also a great call! Oftentimes, winemakers will choose to over-pressurize CO2 at bottling, and this increased dissolved CO2 in the final wine drops the pH ever so slightly. It also adds a bubbly tinge to the wine, creating a unique crispness on the palate, as well as increasing aromatic perception. We thought the tartness melded nice with the green aspects of this wine, carefully balanced the sweetness, and yielded quite a nice wine in the end!

Of note from the above brochure from Dr. Loosen on his 2018 Riesling, these wines undergo what’s referred to as sur lie, or “on lee’s”, minus batonnage, or the stirring of lee’s during a sur lie process. This wine was also held in a fuder cask for 12 months, presumably with little intervention as batonnage was withheld. Fuder casks are 1,000-liter barrels sizing as one of those hipster tiny-homes we all wanted about 2 years ago. They are more non-disposable assets, versus smaller barrel types, that presumably have left behind their extractable oak influence in wines years prior, and provide a vessel for micro-oxygenation, possibly to soften some mouthfeel, and dampen the green character among other things.

Typically, sur lie without batonnage will yield off-odor sulfur compounds from the decomposition of dead yeasts that lie dead in their own wake. How Dr. Loosen has managed to get around this, we aren’t quite sure. As the wine cask remains closed, oxygen will be consumed by phenols and other organic compounds in the wine (fruity esters and ethers, phenols, etc) and form a vacuum. With a greater consumption of oxygen than can enter through interstave space, the reductive potential of the wine system increases, giving rise to reduced sulfur compounds such as the ghastly H2S, other thiols and mercaptans, sulfides, etc. Aeration down the line can help to replenish the redox balance of the wine system, re-convert aromatics, and blow off these negative odors (in addition to all other aromatics present). The fact that this wine sat in barrel for so long may be one of the reasons why aromatics on this wine were much less fruity and floral versus any other Rieslings that we have  encountered.

The coolest part of sur lie though? Not just the breakdown of yeast cell walls and cellular components, but what’s in those cell walls: mannoprotein! They initially exist as a cell wall bound extracellular glycoprotein, but post-autolysis, yields great stuff for wine. Ever had a creamy buttery chardonnay? Take away the butter, and there’s a classic example. (See this ScienceDirect article, also linked in our references, for some great links to more information on mannoproteins.) Without batonnage to disturb the settled yeast, we are presumably getting much less interaction with the wine, and much less mannoprotein imparted. This made more sense given the mouthfeel and body of the wine, as its influence wasn’t as obvious as the acidity and sweetness.

Other things we looked for in Rieslings that we were admittedly disappointed to not have here in this bottle were fusel alcohols and TDN aromatics! Of course, this is a stylistic choice to select for in the final wine, and the absence of them in this wine doesn’t mean anything in particular, other than a choice by the winemaker, but they can be incredibly interesting and fun. Fusel alcohols can range in aroma perception from floral to green, to plastic. Can of tennis balls? Petroleum? Gasoline?!?! These are more often the influence of TDN present. This is one of Taylor’s other favorite aromatics! Upon some further research, Dan found that some certain Australian Rieslings are distinctive for having these petrol-like higher alcohol and TDN aromatics, which apparently are not so prominent in Mosel Rieslings. It will be interesting to try one of these in the future, and the Clare Valley looks to be a great place to find some!

We overall enjoyed this wine. It challenged us and brought some new conversation to the party involving complimentary tastes and winemaking styles. It was different and new for us in some respects, but we were missing some of the aromatics that make the Riesling grape famous. It was all about the mouthfeel and palate for us here; good stuff.

Until next time! We're looking forward to the next round of drinks!

Cheers,

--Dan, Taylor, and Jen

Further reading:

1. An optimized method for synthesis and purification of 1,1,6-trimethyl-1,2-dihydronapthalene (TDN). Alexey Dobrydnev, Andri Tarasov, Nikolaus Muller, Yulian Volovenklo, Doris Rauhut, Rainer Jung.

2. Characterizing aromatic typicality of Riesling wines: merging volatile compositional and sensory aspects. Armin Schuttler, Matthias Friedel, Rainer Jung, Doris Rauhut, Philipee Darriet.

3. Mannoprotein. ScienceDirect.

4. Welcome to Wineoyama!

5. Wineoyama #1: Barolo

6. Wineoyama #2: Pinot Noir