April 25, 2012
September 14, 2011
So many periods of my life have soundtracks. I was fortunate enough to come across some mixes I made for an old buddy who now lives in Greenville, South Carolina. Mike is the type of guy who takes care of things. Listening to the songs, especially grouped together was like going into a time machine. Music can bring you right back to that feeling and that time from when it was prominent in your life. It is why I continually seek for new music. When I was younger it would sometimes be classics that my father or brother passed on to me. That happens from time to time with something that slips through the cracks and was missed when I was younger. You might think, ‘I always wanted to be a bigger Charlie Parker fan, but…’ But that’s not how life works. You either are or you are not. You either have done or have not done.
July 4th in the city of Brotherly Love
I cannot stress how cool the 4th of July concert was on the Ben Franklin Parkway in Philadelphia. With The Roots as the house band, the stage could do no wrong. It was old and young, black and white, urban and suburban and all of the above who enjoyed the OJs start the Love Train, Boyz to Men sing of Motown Philly and Michael McDonald impress the huge crowd (at least 100, 000), possibly because there was recognition of a Nate Dog and Warren G riff.
Overall, I forgot how much I enjoyed that day in Philly every year. It was one of the best days to have your place in the Art Museum neighborhood. I do miss city life for many reasons, but mostly because I spend so much time alone, doing my thing. And living in the city, I never felt alone. I can’t say the same for rural New Zealand!
‘Never gonna break, never gonna break’
..are words that linger in my head from my trip down into the Mid-Atlantic and South Eastern USA. I particularly will remember Charlottesville, Virginia that way. I was heading up to my hotel room and listening to songs and half of songs between sessions of a very good conference in July. The heat that weekend was a dominant force, a reality that could not be avoided. The excitement of pouring my wine for so many new people and meeting some very talented, passionate winemakers and writers fueled the constant trips up and down from the lobby to the 8th Floor. But for the rest of my life when I hear the lyrics ‘never gonna break, never gonna break’ I’ll be right back downtown Charlottesville walking the cobblestones with sweat beading up on my temples, resting in my beard.
Music, for me, is a sense memory. Like smelling fresh bread and being brought back immediately to my grandmother’s kitchen making pizzelles, on a patterned grill press. Music does the same. When I heard ‘Unlikely Cowboy’ I was right back in 2007. A flux year. The year I decided to move from the Art Museum area of Philadelphia to Hawkes Bay, New Zealand. Heartache, wonder and excitement were all rolling around as I tangled with a goodbye to new friend and a new start of finally living my life. The best music brings you to times when you most needed it. Times when you were scared or lost, even if you weren’t aware of how scared and lost you actually are. Actions and results show more true than the daily garbage that can fill your brain. So I am able to look back and feel back to those times and have a feeling on a whole when I hear a certain song. And that song can lead to a revisiting of other music in my life at the time.
So today I’m in a period of new music. Always searching for a new album and a new sound that fits. I am aware that many times I choose melancholy. It somehow drives me . Feeling down sometimes keeps me happy. It must come out. And that’s probably why I listen to the kind of music that exists because it has to. Music that at its core relates to my human experience. My soundtrack today is much different than it was two months ago. Sure there are still those songs on my Ipod, but they’re not in the rotation in the frequency that they once were. It must progress or I will go stale. July was dominated by Bon Iver’s new album. Today it’s Beirut’s new album, a bit of Sallie Ford and a recent flashback to Johnny ‘Guitar’ Watson.
July 12, 2011
I’m at the Starbucks at 49th and Park in Midtown Manhattan and basically flying off my seat. I am worlds away from Hawkes Bay, New Zealand where I spend most of my time these days. The pace here is different, the visuals are different and there are people everywhere. I spent a great deal of my 20s in and around NYC but in the past 4 years in New Zealand it was easy to forget all the things about NYC that make it pop. Today is hot, very hot. Much hotter than any summer day in New Zealand, even on the Gimblett Gravels. The pace is fast. Everyone is sweating. Rich or poor. Stock brokers or street merchants, we’re all sweating. Everyone has a glaze on their foreheads and we all swipe our hair out of the way as we text, tweet and talk on our mobile devices. This little Starbucks rises and falls in waves of people lined up to the door with folks after their fix. The temperature rises in here as the door opens more and more and the temperatures peak as the traffic motors around the Helmsley building just ahead.
But my thoughts remain focused on all of my madness. The travel and the spreading of the word. Tonight it’s Brooklyn for dinner. Then it’s a trip upstate to my place of birth for my favorite kind of event on Thursday. My dream is slowly coming through of taking my passion of winemaking and enjoying it through events with independent music. A fitting start begins with my brother in arms, Tommy Connors. What better way to introduce new folks to the wonders of Hawkes Bay, then with beautiful, live, original music? Instead of knocking on their door like a vacuum cleaner salesman, we’re able to lure folks in like a Nix, as they drown in my wine.
What’s been amazing this particular trip has been the excitement of finally letting the reigns lose a bit and really getting the word out to folks in Philly, NJ and NY. The weather has been hot and the chilled Sauvignon blanc has been met with smiles and dancing eyes of refreshment. I tell folks of the ways we enjoy the Hawkes Bay grown drop within NZ much more than what is grown down in Marlborough. And they can understand why. I’ve been fortunate enough to have poured the wines on two occasions with the pairings from Chef Tod Wentz. I have known Tod for many years, but it is more apparent now than ever, that he is one of the more talented Chefs on the east coast. I say that because I can only speak for the east coast right now.
I look forward to heading up to ‘the Cuse’ for what is hopefully a milder summer. Upstate NY boasts some of Americas most unique (and pricey) wines in the Finger Lakes and Niagra regions. It’s probably a very good time of year to enjoy some crisp Rieslings and Ice Wines. I’ll have to give a full report and possibly some gifts to some friends back in Philly enjoying ‘The Summer of Riesling’.
As my career develops and I continue to spread the word about Decibel, I continue to meet some amazing and passionate people here on the east coast. I’m still processing the information, ideas and laughter given to me from Marnie Old the other night at dinner. Her message of translating wine nerdom from guys like me to the people on the streets drinking the plonk is commendable and challenging. It involves a knowledge and skill set that not many people have. Given what I wrote in my last blog, you know that I’m not a big fan of wankers, snobs and folks who completely miss the point of the wine experience. Marnie, however, gets it. She can sift through the piles of nonsense, get to the goods and then bring to a wide range of folks who need it. I’ll certainly be watching her space in the coming months.
So a quick one for now. But stayed tuned. Lots more to come from the trip upstate to the Cuse, the North American Wine Bloggers Conference in C’ville (VA), and a sneaky trip into Greenville (SC) to visit an old friend. And, oh yeah, I’ve also got a small trip to Napa for 3 months waiting just ahead…..
May 16, 2011
I was speaking with a colleague a few days ago about my aspirations for producing great Malbec wine from Hawkes Bay, New Zealand. We discussed all of the plusses and minuses to producing it and drinking it. The vineyard, the winery, the oak aging, the market, the food and all the interesting bits. After a while he mentioned to me that a top winery in Hawkes Bay who produces some of the finest NZ wines, has some sort of opposition to Hawkes Bay Malbec. They have been known to say Malbec is not a true ‘Bordeaux Varietal’ and produces lesser quality wines. They have been known, in years past, to say that Malbec is all wrong for Hawkes Bay.
Now with all do respect to this unnamed winery, because I truly do love their wines, I could not help but to think the phrase ”what a bunch of wankers.” Now I must admit, I do not know all the details and what was exactly said over the years, officially or just in casual conversation. But I get the jest. And it’s very strange. Malbec has this very cool history in Cahors, France.
And also, who really cares about that? Stop trying to be France. At this stage, a larger portion of wine market doesn’t even know that much about the French, and particularly the ‘true’ Bordeaux, varietals. Just ask anyone who produces Cabernet Franc if they get a bump in sales because of this public knowledge. And as for quality, that’s impossible to know at this stage. Some Malbec vines are showing great results in Hawkes Bay. But there is a wide range of sites and results have definitely varied. So we’re still learning what varietals like Malbec can do.
This year I tasted Malbec fruit from about 8 different vineyards including 2 top Gimblett Gravels sites, 4 varied sites throughout the Bridge Pa Triangle region, 1 from an inland Havelock Hills site, and 1 from a Northern sloped Maraekakaho Road site. They all varied in crop load, canopy management and results. The vineyard results surprised me in that the best fruit came from the site way down Maraekakaho. But those Northern slopes had a great effect this year in Hawkes Bay. And the point is, we don’t know all the potential of Hawkes Bay’s vineyards quite yet. And it will probably be a while before we do know.
On a purely business level, Malbec is more affordable to grow and its popularity, particularly in the US market, is booming. The Malbec from Hawkes Bay is really good, unique in style and could be great if pursued with passion. Like most NZ wines, Hawkes Bay Malbec jumps out of the glass. And it’s easier to grow in Hawkes Bay than Cabernet Sauvignon, Pinot Noir and Syrah. So why would a region limit itself on a potentially successful varietal that is reasonably easy to grow? Why deny people what they want? I guess because a couple of wankers said so.
May 4, 2011
Looking back on the American market on my trip in Dec/Jan and ahead to the trip in June/July.
To say the ‘American Market’ is pretty crazy. It’s fairly irresponsible actually. It’s misleading to my brothers and sisters in winemaking down here in New Zealand. ‘America’, the word, is something that has been said more as an idea throughout the past four hundred years. It sounds of promise, hope and in New Zealand wine it sounds of the dream market. And it usually is a dream. There are so many small, complex, competitive, petty, and bureaucratic rules to getting into just one of any of the 50 states in ‘America’. So please think of it as 50 markets, with 50 different sets of rules, with 50 different kinds of people. That would be a start, at least. I was born in Syracuse, New York. I grew up in Delran, New Jersey and I spent most of my adult life in Philadelphia, New York City and Washington DC. Each one of those 5 places is very different, especially when considering them wine markets. Proximity has no effect on the rules. There is no consistency in regions. It’s a different game in every state. What’s true and ‘the law’ in Pennsylvania seems crazy and communist when you’re in New Jersey. And New York seems wild and free when compared to New Jersey.
For a New Zealand winery (or any wine-producing country) to enter the US market, they must fully commit. You cannot limp into the market. You must commit brands, volumes, time, money, people and all efforts to make it happen. However, the rewards can be great. It is so very competitive for a reason. American wine drinkers, young and old, are more adventurous than most. They’re also more willing to consistently spend money on the drink. The current economic climate hasn’t stopped them from drinking, but it has made it more competitive.
Or at least, that’s what I think. I’m very curious to hear what the ‘industry of drinkers’ has to say at the annual Wine Bloggers conference this July in Charlottesville, Virginia. I’ll be blogging, tweeting @vitisdivine and posting on the Decibel FB page in the weeks and days leading up to the conference. I’m very interested to see how they take on a Philly guy making wine down in New Zealand. After the long days and months of harvesting and fermenting here in Hawkes Bay, I’m excited to be going into the other side of the business. I have a strange suspicion I’m in for a great deal of surprises in Charlottesville, VA this summer.
In some of my former lives (college student in D.C. and band manager throughout the US) I spent some time in Virginia. However, I have no real knowledge of Virginia as a wine-growing region. My hopes are high, though, after my trip to Waltz Vineyards in Manheim, PA this past January. They certainly proved that good wine can be produced in the eastern US. I’ve had nothing but sweet, semi-sweet and generally awful wine from any producers in the east. So I was skeptical and proven wrong. Not only fantastic wines for PA, but fantastic wines for the world. So I look forward to tasting some Virginia wines with promise. Leave a comment if you want to recommend some Virginia wines (I’ll stay away from ‘VA wines’ as a term here and avoid the wine nerd joke).
Lots of changes happening at www.vitisdivine.com including our ‘tour dates’ for the upcoming Tasting Tour in the USA. This page has not been made public yet but get a sneak peek at www.vitisdivine.com/tour-dates
I’d like to thank Susan Tedeschi and Derek Trucks for a great show this past week in Auckland. I was very fortunate to have a quick business trip up from Hawkes Bay line up with the show. And I’m greatful. thanks
April 13, 2011
It’s that time of year. The feeling leaves slowly in the end and you usually don’t realize when vintage settles down for good. You’re left wondering where the past three months went. Then it usually peeters out with a few wines finishing off malo in tank. A bit of a waiting game before everything goes down to barrel for the winters nap before blending. But that seems so far away right now. Right now, you stay awake. You live strange hours and your home life is random, scattered and a mess. My bedroom seems to fill up with overnight with dirty clothes. Stained shorts, wet socks, ripped shirts. Meals are missions like any other part of the day.
On this current day I’m in day 3 of the ‘tweeners’. It doesn’t happen every year, but sometimes there is a lag between varietal harvests that leaves you in limbo. The Merlot and the whites are just about finished ferment but the Cabernet and Syrah are still on the vine. But not every vineyard or winery is in this position. Thankfully, Unison Vineyard did the work necessary to make good or great wine in a tough year.
Hawkes Bay has fallen to some unique conditions in 2011. The La Nina and Cyclones or whatever you want to blame it on have taken their toll on the unfortunate. I’ve seen it first hand with all 5 of the vineyards I worked with this season. Hawkes Bay had an unusually wet summer and cloudy days. There was a nice burst in February but nothing else really worked. But it has settled a bit now, in mid-April. And if you survived the slipskins, the Botrytis, the sour rot, the Downy Mildew and the generally abnormal season for Hawkes Bay, you may still be OK. Every vintage is funny and every site is different. If the passing small storm coming through this weekend isn’t too bad, we may have a fantastic, complex Cabernet Sauvignon harvest.
So hope still burns, for us at least.
September 26, 2010
The wind is blowing. Northwesterlies, westerlies, easterlies, and air is getting warmer. But in my 3rd year in New Zealand I can’t remember a time when the wind was this strong for this long. But it’s also been a mild winter, especially the second half. Much of it was spent in lectures, labs and the library. But now a week long trip through Wellington, across Cook Strait to the small, harbor town of Picton. Picton is always a dream, always in transit, always seemingly random and you turn your head just as another boat is coming or going. So you stop everything you’re doing, watching it arrive and raise or depart and fade.
Then it’s a short ride to Blenhiem. To the big show, Marlborough. Icons like Cloudy Bay and Oyster Bay and innovators like Seresin. Fields of rows and rows of fields of Sauvignon Blanc. Layers of hills of vines in lines that cover and stream. But my palate and curiousity is of the others. The Chardonnay, mostly. I’ve had some stunners over the years from Marlborough. Like many places in the world, the Chardonnay gets overlooked. But in most places of the world all the best make a good Chardonnay.
The trip heads back up north in a few days and we’re posting in Wellington for a night, where I look forward to a hint of the culture I grew to love in Philadelphia. Tighter thruways and metropolitan walks. The interaction with many more strangers always fuels the bloodstream, especially on a short visit. It’s another way in which travel is a pacifying force. A new city, unfamiliar roads and unknown ways will exhilarate and then humble a man.
It’s the leaving and coming back that also humbles. This time of year, especially, makes me think Hawke’s Bay will be quite different when I return in less than a week’s time. Bud burst has crept up on many vineyards already and today a warm wind blows through on the first Sunday night of daylight savings time. When I return it will suddenly be spring and all will have left me behind. I was away. I forgot…that time goes well on without me. That the vineyard must be kept after, the wines must be checked on. The secondary ferments in barrel will have almost completed by now. Time to rack off the wines and give them a spring splashing before you put them down into the cellar for sleep. Time will keep going and we’ll forget about those wines for a while. But they’ll keep going and changing. And I’ll say to myself. ‘I forgot…that time goes on without me.’
Before the return to Hawke’s Bay we’ll stop in Martinborough for the day. That’s about the best way to end a trip. Sneak over the Rimutakas and drop down into the small valley into producers like Ata Rangi and Reid Estate. Young Chris Reid is producing a Martinborough Pinot Noir that I will help him bring to the US in the coming years.
In past years the fruit on Reid Estate has been sold to one of the nearby vineyards. But in 2009 Chris Reid did some trials and made a single vineyard Pinot Noir from the very small block on New York Street. The patch of Pinot has room for more plantings and they will come, but what is there now is high density vines (closely planted) of a very low vine height. The site is run to Biogrow standards and is surrounded by vineyards of Kusuda and Cambridge Road. This past vintage, Chris has again grown the 2010 wine to produce a single vineyard Martinborough Pinot Noir. But it’s a delicate process making Pinot Noir. It’s a different game then most any other winemaking. Only the passionate survive. Hand harvesting and sorting tables, berry selection, time, careful, methodical. The air of the Old World is felt with the eye on the prize of the delicate giant that only Martinborough could produce.
So I’m hoping to taste the 2010 in barrel and see how it’s coming. Nothing like a little taste of the future. This week-long trip is one of time travel anyway. When I arrive back to Hawke’s Bay, spring will be on. Next post will surely have some beach shots from the Bay. An update on the 2010 Decibel Single Vineyard Malbec is well overdue. But now is time to head south…
In the mean time check out www.vitisdivine.com/restaurants . Wines are starting to pop up and could be available near you very soon.
August 25, 2010
Production of S-containing Compounds
(H2S, SO2,mercaptans, DMS) by Yeasts
The production of sulfur containing compounds by yeasts can occur at any stage of a ferment. It is generally undesired in ferment as it produces a variety of off-odors, reducing the quality of the wine. In winemaking it can occur in any vintage, any country and in all must types: red, white, rose, sparkling or botrytis-infected. It can occur in ‘under turbid’ or ‘overly turbid’ wine or juice as well. The causes of sulfur containing compound production by yeasts are rarely determined because of the difficulty of prediction or diagnosis in the complex matrices like grape juice and wine (Ugliano, et al. 2009). It is because of these reasons that the study of the production of sulfur containing compounds by yeasts has been and remains to be a very important topic in winemaking. In short, it’s a battle all winemakers must all take on in their careers and management of the issue is essential to quality winemaking.
It is crucial to be familiar with the terms and chemical structures of the different types of sulfur containing compounds as they each have different orgins or are at different stages of the development. Each of these structures can also have individual effects on the ferment and finished product. And they are each percieved in different ways, if at all in their particular state.
Hydrogen Sulfide production is a common occurance in fermenting yeasts and is percieved as an ‘eggy’ or ‘rotten egg’ aroma. It is commonly reffered to by it’s chemical formula, H2S.
Sulfur dioxide, SO2 , is also something that must be considered during a ferment. Its role in winemaking is crucial and must be considered when factoring in the components to Sulfur containing compound production.
Sulfate, SO4 is important in its role within the sulfate reduction pathway.
HSO3, sulfite is also another important step in the sulfate reduction pathway and consider that salts containing the HSO3− ion are termed bisulfites.
Disulphides represent the latent form of sulphides in wine and are an important factor, especially in wines that are put under more reductive closures such as screwcaps (Ugliano, et al. 2009).
Not to be forgotton in the equation, organic sulfur does play a role
Mercaptans, also known as thiols, are a large group of particularly smelly sulfur compounds in wine. They tend to smell more like burnt rubber or cabbage rather than the eggy smell of sulfides. It is the result of hydrogen sulfide not being removed from the wine. What also complexes the issue with mercaptans is that they sometimes are desired aromas depending on the wine style. (Goode, 2010). Most mercaptans have generally low sensory thresholds, some tracked as low as parts per billion.
Origins of sulfur-like off odours
If it can presumed that there can be ‘normal’ conditions in a ferment, the most important source of hydrogen sulphide production during normal conditions is from the reduction of sulphate via the sulphate reduction pathway (Zoecklein, 2007). The yeast uses this hydrogen sulphide to synthesise methionine and cysteine. These are the only two sulfur containing amino acids and are both essential amino acids for the yeast growth. But in the shortage or absence of nitrogen, the reduction of sulphate or sulphite continues, forming an excess of H2S that cannot be incorporated into these amino acids. This excess H2S is then passed onto the medium, that is, the fermenting juice or wine.
There are other origins of sulfur like odours in the ferment, though many are inter-related. High levels (greater than 80ppm) of SO2 added to the must at crushing can increase the production of sulfur-like off odours by allowing SO2 to enter the yeast cell directly (Practical management, 2009). In this case, the sulfate reduction pathway is actually bypassed. Usually, though, such high additions are uncommon as yeast metabolism is inhibited and fermentation fails to commence.
The turbidity of juice can also influence the production of sulfur-like off odours (Zoecklein, 2007). Jucie turbitity is measured in nephol turbidity units (NTU). If the juice has a low NTU it will have ferment to a wine with greater aromatic finesse. But a juice with a low NTU usually means it is nutrient depleted with low yeast assimilable/available nitrogen (YAN) levels. And juice tubidity that is too high can also result in the production of unwanted sulfur-like such as high boiling compounds like disulphides.
Winemaking practices such as cold soaking before the ferment can be favorable to non-Saccharomyces yeasts such as Kloeckera spp. The growth of these other yeasts can deplete the juice of amino acids and micronutrients, effecting the production of H2S. This is also a risk when doing indigenous yeast ferments. Because these yeasts tend to have a longer lag period, the window of opportunity is greater for non- Saccharomyces yeasts.
When vitamin levels are low in high YAN musts, yeasts will also breakdown the amino acid, methionine, containng Sulfur. The yeast does this to obtain the amino group, panthothenate (a vitamin).
Vineyard practices are not usually to blame but can be the reason for sulfur-like off odors in a fermenting yeast. The use of elemental sulfur in the vineyard as a fungicide can be one reason. If residue limits and dates are not followed accordingly, residual sulfur could remain in the must. Also, diseases like Botrytis cinerea and pests such as Mealy Bug can severely deplete the nutrition of a grape must or juice.
Still, the latter few of these mentioned play a lesser role in the production of H2S. The exaustion of YAN is considered to be the common cause of H2S production (Theron, 2009). During the exponential growth stage of yeasts during ferments nitrogen demand is high and yeasts are metabolising in different ways to compensate for the shortage in the nitrogen pool.
Managing Hydrogen Sulfide Production by Yeasts
The timing of the production of sulfur containing compounds and the timing of the treatment of these issues are the essential factors in the battle for winemakers (Ugliano, et al.) First, consider the timing of H2S production. It is now more widely excepted that early production of such off odours are less of a concern to winemakers worldwide. It is because these odours tend to not remain in the finished wine, especially if dealt with properly at the early stages of the ferment. More recent research also suggests that it is not the amount of H2S production but rather the stage of the ferment in which it is produced.
Consider Figure 1 which shows a representation of H2S production by yeast during fermentation in a low nutrient juice or must where the YAN is represented as a light blue cloud running out quickly as the yeast enters the exponential growth phase.
(Ugliano et al. 2009)
This graph (Figure 1) represents four different ferments in a low YAN situation. The ferments in red are not as worrisome for winemakers as it is shown that H2S production has ceased well before the end of the ferment and off aromas have time to blow off. During yeast growth phase the associated high fermentation vigour leads to rapid loss of the highly volatile H2S by entrainment with CO2. Entrainment means that these systems (production of H2S and production of CO2) can act independently but during a ferment they seem to act together and rid the ferment of the off sulfur-like odors. Though later on in the ferment when the ferment vigour is lower CO2 production slows, H2S production is less efficiently removed from the must. H2S production is also removed less efficiently at this stage in larger fermenters (Ugliano et al. 2009). Though it is not completely understood whether or not the H2S reacts within the complex matrix of the must to form some of the more complex sulfur containing compounds such as mercaptans, disulfides and thiazoles (Rauhut 2009). Regardless, detection and management of H2S production is crucial. Experienced winemakers with good palates and sense of smell can detect hints of H2S production and address the problem before it gets to a stage in which it is a larger problem. Many wineries do not have the facilities or trained lab technitions to be able to keep up with YAN counts of each ferment. So early detection from the winemaker of these off sulfur-like odors is crucial so the problem can be managed properly. This is most easily managed by the addition of Nitrogen into the must or juice through the means of diammonium phosphate (DAP). Once added H2S production should cease to begin and what has been produced will blow off with fermentation vigour. But different results will occur in different musts and with different yeasts as seen in Figure 2.
Figure 2: µg H2S in head-space per g sugar metabolised (Ugliano, 2009)
Figure 2 represents two different yeast strains, A and B performance in low YAN musts starting with 100mg/L with DAP additions raising the YAN to 250mg/L and 400mg/L in the grape must. Different amounts of residual H2S existed in the wines varying between DAP addition and yeast strain. And performance varied as well. In some cases such as the DAP addition to 400mg/L YAN in yeast B delayed and prolonged H2S production leaving some residual H2S in the wine. But with no DAP addition in yeast B though initial H2S production was higher than the other addition rates, it was early and eventually ceased to exist in the final wine. Also notable is that though yeast A with no addition of DAP produced much higher amounts of H2S, it had none detectable in the final wine, once again showing that timing of the production of the sulfur-like odors during the ferment is important.
Probably most notable in this graph is the performance of the two different yeast strains. This is probably why so much effort has gone into developing commercial yeast strains and why it is considered the best tool for controlling H2S content in wine (Ugliano et al. 2009). It is impossible to know from vintage to vintage, vineyard block to vineyard block, and ferment to ferment if YAN counts are going to be low and contribute to H2S production. However, Figure 2 also shows that much is to be learned about different yeast strains performance in different must types. Clearly, each scenario produced very different and not very predictable results. Sometimes even negative responses can occur with what was thought to be a positive influence such as a DAP addition early in the ferment. Much more research is needed as these types of biochemical mechanisms are unclear.
Why is managing late ferment H2S so problematic?
H2S production is considered late in the ferment typically after yeast growth has finished, usually when sugar levels are below 50-100g/L. This can vary greatly among yeast strains as well as varieties. For instance, Syrah tends to problematic but Cabernet Sauvignon tends to have less issues with H2S production (Theron 2009). Late ferment H2S production is also typically unresponsive to additions of DAP. It is thought that at this stage the yeasts are using organic Sulfur compounds such as methionine and cysteine as sources of Nitrogen and may be past the stage of looking for Nitrogen in the typical Nitrogen pool of the must. But the recovery of Nitrogen through these sulfur containing amino acids leads to the release of H2S (Hallinan et al. 2009).
Aeration can be an effective means for ‘blowing off’ H2S at the later stage of the ferment when removal by entrainment with CO2 is slowed later in the ferment. However, this aeration can lead to the production of disulphides in low concentrations of H2S if mercaptans (thiols) are present. So there is no easy answer and again, experienced winemakers with sensitive palates can detect the difference between these levels of H2S and possibly if mercaptans, whether beneficial or not, are present. This could influence the winemaker to decide not to aerate and hope the H2S blows off over time and avoid later problems. That is, at a later stage if undesired mercaptans and H2S is present in the wine, trials with copper sulphate can be performed. But copper sulfate is not effective in removing disulphides, and these can appear as later as they will revert back H2S if the wine is bottled under reductive conditions such as screwcaps. But copper additions are not that discriminatory and can removed desired thiols imporant to varietal characteristics such as the 3MH and 3MHA in Sauvignon Blanc.
Vitamins and other nutrients
Vitamins can be an effective tool in controlling H2S production because vitamin deficiency can be directly related to H2S production (Henschke et al.). Sound, healthy fruit is a key issue. This can be due to vineyard disease but also handling during harvest, transport, and destemming/crushing. Proper use of Sulfur dioxide to avoid microbial growth or wild yeast growth prior to inoculation can help avoid depletion of thiamine, leading to sluggish ferments. But careful use of SO2 must be considered because if levels are too high this could also cause H2S production or impale the yeasts and cease fermentation from beginning. Also, certain soils and certain vineyard blocks can consistently produce fruit low in certain nutrients and vitamins.
In many wineries it is very common to use yeast vitamin preparations at or before inoculation along with a small amount of DAP can control H2S production. And late ferment H2S production can respond well to vitamins, though it may only be lowered and not eliminated. There are many of commercial nutrients on the market and many wineries use these during yeast inoculation (starter culture) and during the ferment. However, some of these do not contain sufficient amounts of Nitrogen to help with production of H2S.
Though the prediction and management of H2S production is difficult and much is to be learned, there are a great deal of studies currently being done. For now, it seems the best way to manage such issues in wine fermenting yeasts is to be proactive in chosing yeast strains and detecting H2S production early in the ferment as possible. Early allows for more options in managing the issue and options that will most likely help the situation without it arising later in the wine be it at the finish of ferment or much later after bottling. New World wine producers must be particularly careful as many now opt for reductive closures, causing latent issues. Still, chosing of yeast strains that work well with grape musts with the proper level of yeast assimilated nitrogen pools is the best way to limit the production in the first place.
Goode, J. (2009). Mercaptans and other volatile sulfur compounds in wine. Retrieved 26 July 2010 from http://www.wineanorak.com/mercaptansinwine.htm
Jackson, R.(2008) Wine Science. 3rd Edition 2008.
Lee, S.A. (2008). Grape juice is the major influence on volatile thiol aromas in Sauvignon Blanc. The Australian and New Zealand Grapegrower & Winemaker No.533a 36th Annual Technical Issue. p. 78-86
Theron, C. (2009) The practical management of Hydrogen Sulphide. Courtesy of Wynboer Dec 2009. Retrieved 5 August 2010 from http://www.wynboer.co.za
Moore, D. Course handouts (2009). Structural and Metabolic Biochemistry. Eastern Institute of Technology 2009.
Practical management of hydrogen sulphide during fermentation – an updated overview according to recent studies on red wine fermentation (2009). AWRI puplication #1121. Technical review 180, June 2009.
Ugliano, M., Winter, G., Coulter, A.D., Henschke, P.A. (2009) Practical management of hydrogen sufide during fermentation – an update. The Australian & New Zealand Grapegrower and Winemaker. Annual Technical Issue 2009. p. 30-37
Zoecklein, B. (2007). Yeast production of SLO. Taken from a presentation given at the 8th Annual Enology and Viticulture British Columbia Grape Council Conference, July 23-24, 2007.
April 12, 2010
I’m home, 9:30pm. 2 days past of picking and bringing Merlot into the Unison winery. The fruit is clean. And I think it’s best I just post what I just wrote by hand in about 7 minutes or as fast as my hand could write:
David was never king
He was me and you, screaming only through his
life a dream he had about his life as
a king who did it the way his mind
said it was right to do.
And in the field I found my way through
all my life. Through rows of trees as
high as my head and I could peer
above them and see everywhere.
But I could duck down in the shade
and hide till the sun rose high
enough that all I could feel was
the burn on my nose and the red
on my neck which I could feel late
at night as I lie in my bed, alone
with the the thoughts of only tomorrow.
Tomorrow brings what the season
promises, a new life for us to make
our own, to alter, change, consume
exhume and give back, if our hearts
are truly historical, bonded to the
society of man and willing to live
on well past the time the sun
will ever blaze our cheeks and ripen
the fruit we call our own.
And maybe some of the memories
are left in the bottle and the others can drink
it and feel as I do, alone in a bed
with the blaze across my nose
and the warmth on my neck.
December 13, 2009
Please be sure to dive in and click on the various hyperlinks throughout this blog.
As a kid I was obsessed with wheat fields. I’d find hiding places in trees that looked over clearings of tall grasses, and I would just watch. I would think about one day having my own house on a hill near a wheat field. And this was years before I discovered Holden Caulfield and or even Steinbeck. I even wrote poems about wheat fields and submitted them unanimously to the high school literary magazine. I distinctly remember writing about the tall, mature stalks being strong but affected by the winds and forgetting the pain of youth so quickly.
As I got older, I continued to dream of waves of wind riding over the tops of the long, rolling fields. I would forget about those dreams for a few years, though. Then on my first trips across the Midwest of the US with Seeking Homer, I was reminded again, imagining buffalo herds and watching windmills sway. I found the fields again in Iowa. I would see them through the windows of our tour bus, but they always seemed distant, and never mine to embrace. Then more years passed and it has taken more time, but I have been reminded of those youthful thoughts foreshadowing my days in the vineyards of Hawke’s Bay, New Zealand.
Spring time in the vineyard especially reminds me of those dreams from years ago. The sun warms my hands and neck as the cool breezes and southerly Pacific winds cascade waves over the canopies that aren’t quite green yet. The straw hues of the shoots and tendrils that have reached higher than the others stand out across the rows of vines. These are the vulnerable, not strong with the deeper greens lower down the canopy. The tendrils reach for the sun and wrap around anything they can grasp, including each other. These high shoots, yellow, almost translucent, will many times be beaten down by the southerlies, broken from being exposed and held back by the roots and the lower lying vine. But some will make it to the fall and those will produce the sweetest fruit you’ve ever known.
OK, so enough day dreaming. But each spring we go through this, imagining what the harvest will bring this year. Right now, in Hawke’s Bay, this year is in question. I have been told it’s been the coldest spring in 50 years for Hawke’s Bay. And though we’ve avoided the frosts this year, many of the vines are significantly behind in maturity. But that’s nothing a hot summer can’t fix. And Hawke’s Bay has been known for them. Today is Sunday, November 29 and it feels hot. But more rain is coming this week and we begin to ask ourselves ‘When will the blaze come?’.
On another note, I had recently put together, a very practical, easy to read power-point presentation which I have posted on slide share. It’s a specific case of transplanting vines at Cottingham Estate in the Triangle of Hawke’s Bay. A bit nerdy in parts, but certainly something that any novice can appreciate and take some interesting bits and lessons in viticulture. Check it out on Slideshare at http://www.slideshare.net/vitisdivine/transplanting-vines
More such documentation is coming, and these blogs will be much more frequent in the coming weeks. Now that my schooling is on pause till May and my head is not filled with ideas of metabolic biochemistry and uses of Atomic Absorption Spectroscopy, I can focus on communicating all the happenings in Hawke’s Bay to the rest of the world. The next Slideshare.net presentation will be an ongoing project focusing on Foliar Seaweed Sprays on an organic block of Sauvignon Blanc at Villa Maria’s Joseph Soler Vineyard in Hawke’s Bay. Without getting into all the gibberellins and other hormonal activities, it is becoming more commonly viewed that vines that use these seaweed sprays are happy, healthier vines, much more resilient to virus and disease. So this year we’ll be looking to prove, in one such example, the ‘what’ and not necessarily the ‘why’ or even the ‘when’ of advantages of using foliar seaweed sprays. That is, we’ll be looking at incidence of diseases such as botrytis or powdery mildew and overall fruit maturity for wine growing (Brix, TA, pH, etc) along with a few other detailed observations. So we’ll track the Sauvignon Blanc with two Seaweed sprays. The two companies providing these applications are Agrisea NZ and Acadian Seaplants Limited from Canada. We’ll also look at a control, on which no Foliar Seaweed sprays will be used. My Slideshare presentation (a work in progress) has been started here and I will continue to upload and provide updates on Twitter.
I promised a movie to many of you in this next blog, so check this out on youtube.com
Some exciting news coming in 2010. Until then enjoy the holidays….