Some Thoughts on Syrah & Reduction


I recently sent out an email. which stated the following, & here are some of the responses I got back.  I purposefully did not include names, as who said what is not the point.  It really is about sharing insights & learning from each other.  I have found there is never just one answer.

I am writing a piece on Syrah and am hoping to get your thoughts on the subject.  I recently read somewhere the Syrah has a propensity to go “reductive” in bottle.

What does that mean?  How?  Why?

Is there other grapes with this tendency?


Reductive, anaerobic, as opposed to oxidative.

Reduction can show as shut down with muted aromatics and palate to an extreme of stinky, sulfitey aromas and off flavors.

Syrah is notorious for being reductive in the cellar, as well. Wines are made using non-oxidadative techniques more and more, resulting in wines with a tendency towards reduction. Syrah is oftentimes aged on lees. This helps protect the wine, keeping CO2 in solution and oxygen away. This can drive the wine further into reduction.

When I’ve had the opportunity to taste at Clape and Faury they pour young Syrah’s from foudre or barrel, they are often reduced. They often then follow with the previous vintage out of barrel and bottle and the reduction has disappeared.

Syrah made by Cabernet Sauvignon makers where they rack and return the wine often tends to be less reductive. However, the wine tastes less like Syrah, in my opinion.

I like having some reduction in our Syrahs, and most of our wines for that matter, during the aging process. Keeping our wines on lees in barrels enables us to use less SO2 during the barrel aging process. The wines tend to be a little closed, especially during the winter. I like that. The wines evolve slower and are a little tight when bottled. A little time in bottle or decanting will help.

If a vineyard has been sprayed with sulpher too close to harvest, there will often be some residue on the grapes and will result in stinky, reductive, sulfite-like aromas and off flavors in the wine.

Chardonnay comes to mind as a variety that also tends to be reductive. We always have several barrels that show those reductive characteristics. These barrels tend to be barrels that were the last filled from that particular lot and tank. So these barrels likely have more lees and heavier solids in them.

I’ve read recently regarding the style of Chardonnay winemaking, Burgundy in particular, and the inclination winemakers have towards the reductive, matchstick quality. Think about winemakers whose style and trademark go hand in hand with the matchstick quality: Coche-Dury, Roulot, Pierre Yves Colin.

We like some of that character in our Chardonnays, for sure.

It’s a fascinating topic always worth chewing on.  I’d love to hear your impressions and thoughts on it and your experiences with wines in bottle and in winery cellars.

I did forget to some notes regarding nutrients during fermentation.

If a vineyard is low or deficient in nitrogen, the grapes or juice in the fermenter will be low in nitrogen.  We know this by a juice sample we send to the laboratory to measure sugar concentration, acidity, potassium, and nitrogen and ammonia for fermentation.

Yeast, native or lab, can stress during fermentation if there aren’t enough nutrients in the must. A too warm fermentation and not enough oxygen will also stress yeast. When yeast are stressed, not only is there a risk of a stuck fermentation but the wine can also end up with the hydrogen sulfide spectrum of odors and flavors – extreme reductive smells and flavors.

We don’t add nutrients to our Chardonnay. We taste and smell our red fermentations along fermentation observations. If there’s an off smell or flavor we’ll pump it over longer to introduce some oxygen to the fermentation. Usually, that helps a lot. If that doesn’t do the trick we will add small doses of yeast nutrients to rid the wine of those attributes. These nutrients include nitrogen, ammonia,  yeast hulls.

It’s much harder to rid the wine of any of those characters once the wine is dry and in barrel.


Without getting into gains and losses of electrons, “reductive” is a loosey-goosey term used by wine tasters to refer to a wine that show sulfur-based aromas, things like rotten egg, burnt rubber, burnt match, rotten cabbage, etc.  With oxygen, these sulfur-based aromas can dissipate to reveal the true character of the wine but occasionally they can develop into something more permanent.  Copper sulfate is used to remove excess sulfur based aromas but it does not remove mercaptans (more the rotting cabbage/onion smell).  Why is Syrah more prone to reduction?  I don’t know exactly why but it may have to do with with the lack of nutrients available for yeast and/or the chemical makeup of Syrah.  Other varieties with which we work that are prone to reduction during elevage are Mourvèdre and Petite Sirah.  Interestingly, I have never had a reductive Zinfandel.  Sulfur-based compounds play a significant role in the aromas of many whites such as Riesling, Gewurztraminer, Colombard, Sauvingon Blanc, and Petit Manseng.


For a nice overview of reduction in wine see (http://nanaimowinemakers.org/Steps/H2S_Issues.htm) Syrah and other varietals ( Riesling, Sauvignon Blanc and certain Pinot noirs for us) have a biochemical propensity to resist oxidation and therefore being reductive. It is positive as it gives them a greater ability to age but will also present challenges as it goes through phases where it generates sulfur compounds that change the fragrance and mouth feel of a wine (usually for the worst or at least masking other features). It is complicated to explain as Oxidation and reduction happen at the same time and has to do with layers of chemical reactions I am not that comfortable with and are actually not that well understood. We learn how to link it with, the farming, the fermentation, nutrients, temperatures etc. One becomes familiar with it through sensory analysis and empirical observations.

You know I’m not a chemist so I’m sure you will find the chemistry answer from someone else.  What I can tell you is the practical side, and that is Syrah is opposite of Pinot Noir in this regard.  I take a completely different approach in protection of the two varietals.

Pinot needs to be protected from oxygen, it breaks down easily, the color, the aromas the textures all seem to be unstable.

Its its not cellared at the right temp, if the lees are not perfectly clean, if the ph is too high, if the free so2 is below molecular threshold, pinot can fall apart.  I only go 6-9 months before the lees have consumed all the extra o2 thats available, and needs to be racked then sulfured.

Syrah on the other hand is very forgiving.  Although I cellar everything at the same temp, (55 degrees year round) syrah eats up oxygen at any opportunity.  I typically go an entire 24 months in barrel on the gross lees before its racked for the first time and receives its very first addition of so2.  Pretty crazy huh?   Obviously I only work with cold climate syrah (low ph, high acid) and this allows me to take this approach with much more confidence, because the chemistry of the wine is stable.

Reduction is lack of oxygen.  Syrah eats up oxygen and when its tapped out the wine goes into a reductive state.  Once the wine hits more oxygen, the reduction aroma lifts off the wine like a protective blanket.  Chardonnay (Roulot is a great example) is another grape always flirting with reduction.


Syrah does have an odd perpensity to become reductive or form H2S, Hydrogen Sulfide or rotten egg aroma.

So does Gamay. People think it is due to the thick skin on a big grape. Serine which is smaller doesn’t do it as much. It is tougher to aerate after it forms because it oxidizes easily. It probably has something to do with the nature of the chemicals in the larger skins.


This is a complicated issue.

‘Reduction’ is not a term used consistently in even the most technically savvy wine communities.  It can be a term for a ‘not very splashy racking strategy’ vs reduced sulfur compound formation at some point in the wines development. The t wo do not have to be connected by anything other than Sulfur being part of the chemistry.

Sensory wise, it’s about how volatile thiols pose themselves according to the reduction-oxidation potentials of their parallel equilibria.  If they are not there in large numbers or in highly stinky form, nobody senses them.  If conditions vary to Chang amounts or forms, even low levels are distracting.  It’s not a nutshell subject.

Makes sense now.  Right?

The two usages of the term are not joined at the hip.  It drives me crazy.  Once you have Carbon and Sulfur joined, the options become…complicated.

Think more about HOW you get there vs WHERE you happen to be.

There’s way more to say on the subject, but I’m tapped out right now keeping things at home happening.  Plus, I’m no expert chemist. I only have a BS with at-home graduate studies and decades of experimentation.

Thank you for digging into that mud hole.  It is a fertile subject.

Keep asking those questions.


Never if one’s systems are in place.

“Reductive” is an excuse.


I find that Syrah likes a traditional approach to fermentation, and using native yeast, moderate amounts of nutrients, low SO2 at the destemmer, some whole cluster inclusion, all help to bring the level of sulfide development in the must to about the same level as any other grape. Basically, sometimes a little happens, but if it is a small amount I don’t worry about it too much.

Regarding elevage, I find it all starts in fermentation, so if the lees are clean and your fermentation went well, no further problems occur. I keep Syrah on the lees for about 8-10 months usually, sometimes longer, with no problems.

If Syrah goes reductive in bottle, it was already reductive in barrel. period. The same thing goes with screwcaps. It was a problem that the winemaker thought was addressed, which reared its ugly head again in bottle.

But, as others have noted, some “reductive” compounds bring typicity in small amounts. I don’t mind it in small amounts, but I don’t want to smell vinyl or perm or diapers. 🙂

I also am not a fan of many Roulot wines that too me are deeply flawed. Coche on the other hand I think is well judged.

Categories : General, Red, Wine, Wine Thoughts

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