Wednesday, 30 October 2013

Trialing times. Finding out more about English wine

Over the years I have been teaching winemaking at Plumpton College, I have slowly but surely been setting assessment tasks which can engage the students.  One of the assessments that I particularly enjoy setting is the vinification trials. Here year 2 students team-up to make wine that explores a set of vinification treatments using English grapes. They need to research the treatments, help design the trial, carryout the winemaking & analysis and then finally conduct a tasting of the trial wines with the class.

Muller Thurgau

This year we are investigating the following areas:
  • Protecting and enhancing aroma in Muller Thurgau wine using enzymes and yeast derivatives.
  • Examining the influence of maceration times on Dornfelder red wines
  • Investigating the role of yeast strain on Acolon Rose wine
  • Investigating new yeast strains on Reichensteiner white wine
  • Developing thiol aroma in Bacchus white wine
  • Assessing the impact of cold maceration and enzymes on Dornfelder red wines  

Acolon Rose yeast trial
Most of these trials are now underway, with just Reichensteiner to inoculate

Besides examining the impact of the treatments the students get a taste of managing wine ferments which include making correct additions, taking timely and accurate measurement as well as ameliorating potential problems such as hydrogen sulphide and volatile acidity.

Beside the vinification trials we also have a few student project wines being made.  So we also have trials underway that look at different vineyard planting densities of Regner vines, Non-sacchromyces in Pinot Noir to name a couple.

Pressing Regner planting density grapes
So the Rathfinny research winery is being well utilised, with students popping in and out all hours of the day and on weekends tending their ferments, and getting them used to the demands of a vintage.

Saturday, 19 October 2013

Off to Dijon!......"Do you have what it takes to be a world class sparkling wine judge?" part 2

Working at Plumpton College can be hard work, lectures to prepare, students to advise, assessments to set and mark. When I first start teaching, I naively though that after the long hours I had experienced as a winemaker I would now have a more normal "9-5" workload and consequently lots of free time. When the Principal of Plumpton College warned me that I would have to work hard, I smiled and said fine, sure in my belief that winemakers know plenty about hardwork.  I soon discovered I was wrong and the Principal was right.  Those first years of teaching were tough, lots of late nights, early mornings and weekend work. However I survived those years (helped by many therapeutic summer holidays in Italy to relax) and settled down with the teaching. However Plumpton College is dynamic environment and there is always something extra to be done. The course content and structure is always being revised to makes things better, there is always new staff to interact with offering new ideas & knowledge that make you re-evaluate what you know as well as new developments such as the new MSc in Viticulture & Oenology. Another thing that keeps us busy in student study trips and one I have been involved in is leading a group students to judge at the Effervescent du Monde sparkling wine competition.

To become a judge a Effervscent du Monde, you must participate in a training session, which was run yesterday. This year we extended the invitation to UK grape growers, wine makers and people in the wine trade. We had an excellent response and over 20 people participating in the training session.

The training is crucial, as the Effervscent du Monde are trying to improve accuracy and precision in its judges. This is very important with sparkling wines as they are more difficult to judge then still wines because they are very influenced by the way there are served.  This was highlighted in the lectures given by Professor Richard Marchal from the University of Reims, that showed that Mousse and Effervescence are influenced by many factors including shape and cleanliness of the glass, amount of wine poured, wine temperature and time from pouring. This in turn impacts wine aroma and flavour. Professor Marchal used this information to inform us how the wines should be served and importantly how the wines should be judged.

Professor Richard Marchal talking about Effervescence and foam

We also hosted Jean Claude Buffin, who discussed how the du Monde wine shows are conducted. The aim of the competition is to improve the accuracy and precision of the assessments.  He also discussed at great length howjudges may be influenced in the decisions they make and steps that can be taken to reduced this problem.

Part of the judging sheet for Effervescents du Monde

After this we participated in a series of tasting session to practice the judging system using a variety of sparkling wines including Champagne, Cava, Prosecco and of course English Sparkling wine. It wasn't long before the would-be judges got the hang of the new judging system and started to give some consistent results in their assessments.

You can also read Laura Clay's blog post on the day here

So now that training is over, its time to plan our trip to Dijon for the actual judging. Of course going to France and Burgundy means that the the trip can be enriched with some extra activities. On this years itinerary we hope to include the the following:

Cellars of Champagne Drappier
Hospice de Beaune Burgundy in barrel

I can't wait and if its a good as last years trip (read about here) it will be a great wine experience.

Tuesday, 8 October 2013

Do you have what it takes to be a world class sparkling wine judge?


Plumpton College in conjunction Professor Richard Marchal (Reims University) and Jean Claude Buffin (author of Le vin: pratique de dégustation), are offering a one-day course on the sensory evaluation of sparkling wines to prepare judges for the prestigious Effervescents du Monde competition. This world-leading sparkling wine event is held every year in Dijon (Burgundy). See for further details

The session will focus on sparkling wine effervescence and mousse and training judges in the objective measurement of wine quality using the Effervescents du Monde judging system. There will, of course, be a wide range of sparkling wines to taste.

Upon the completion of this one-day course, delegates will be assessed and may then become qualified to judge at this year’s Effervescents du Monde competition.  

This event will take place from 9:30 a.m. to 4:30 p.m. in the IOC tasting room at Plumpton College, near Lewes, East Sussex BN7 3AS on Friday 18th October 2013.
The price for training £85, including wines, and a light lunch.

Please register your interest by the Plumpton College contact page, using "wine studies" as the area of interest and include "Sparkling wine tasting day information" in the comments section.

Monday, 7 October 2013

Champagne harvest: A short video

I spent the second half of last week at the University of Reims, where I was conducting some experiments with Laccase and sparkling wine juice. I plan on writing about this later.

However while i was there I shot a short video in one of the wineries we are taking samples from.  I was very impressed with the facilities of the Coopérative vinicole de Nogent l'Abbesse, which serves the most North Easterly vineyards of Champagne .  These vineyards are located on a small hill near the villages of Nogent l'Abbesse, Cernay-lès-Reims and Berru and are predominantly Chardonnay grapes.

Nogent l'Abbesse, North East of Reims

In a period of 10 days, the winery will process approximately 4000 tonnes of grapes through a winery, using some of the most up-to-date winemaking equipment available.  The video below highlights how the grapes get from the grower into the winery where there are whole-bunched pressed into juice.     

Tuesday, 1 October 2013

Ciocâlteu: Professor, Poet and Political victim

I have been using some FC Phenol reagent, which a mixture of acidic phosphomolybdate and phosphotungstate, in the lab yesterday to measure phenol content.  It provides a quick snapshot of the gross quantity of phenolic material in samples, as outlined in this elegant method provided by Dr Andrew Waterhouse from UC Davis. It is usually abbreviated to FC by staff and students as Folin- Ciocâlteu  reagent is a bit of a mouthful for English speakers.

FC reagent with its distinctive neon colouring
However I decided that I would like to find out more about the Ciocâlteu part of this reagent's name, which led me to the very interesting story of Vintilă Ciocâlteu.

I am going to start with an interesting fact that Ciocâlteu helped provide the method that has had arguably the single biggest impact on scientific literature for all time. This impact was through the work of Oliver Lowry and his team, who in 1951 published a paper "Protein Measurement with the Folin Phenol Reagent" in the Journal of Biological Chemistry. This paper and the methodology has been cited an incredible 248 682 times (as of today 1st Oct 2013), making it one of the most influential papers in modern science.  Almost a quarter million science teams have looked into this study, whch was initially made possible by the the work of Otto Folin, Wiley Glover Denis and Vintilă Ciocâlteu.

From such interesting contribution to chemistry, it is easy to follow the history of Vintilă Ciocâlteu the Romanian scientist behind this chemical, and what follows is a brief outline of his life, which I have adapted from this historical article

Born in Romania in 1890, he graduated as a physician in 1920. He did incredibly well with his studies an was awarded a Rockfellar scholarship to leave Romania and study in the United States at the Harvard Medical school. It was in 1925 he worked for Otto Folin, considered to be one of the founders of Biochemistry and spent many productive years in the lab, including the work on the eponymous reagent. 

Vintilă returned to Romania, where he was deeply involved in university life in Bucharest.  He gained his professorship, started new laboratories for biochemistry and eventually became Dean. Biochemistry wasn't his only passion and he was known in Romania as eminent Poet publishing two collections of poems and being widely involved in the literary scene.  

Of course the country of Romania was about to experience one its most turbulent phases in history. Initially with countries involvement in fascism, then its subsequent take over by Soviet state.  It was during the period of communism that Vintilă became under suspicion from the state as intellectual and a liberal.  This was compounded by the fact he ha received substantial training in capitalist America.  He was demoted from his post of Dean, while the authorities conducted a smear campaign to renounce his good works.  In 1947 he was summoned to the faculty senate to defend his cause.  He duly did so for two hours, presenting the importance of his career and discoveries to his peers. It was at the end of this political witch hunt that Vintilă succumbed to a massive stroke and he died on the senate floor to eternal shame of all the attending academics.

So after learning of this interesting story, I can't help think about the importance of science, politics, history and I now make it a point to tell my students about how this strange yellow/green liquid came into being. 

Sunday, 29 September 2013

Syringaldazine and sparkling wine

Last week I was preparing for my trip to Champagne that is occurring this week. I will be working with my Colleagues from University of Reims, collecting samples during grape processing. We have had to wait until the CIVC had declared the Vendage dates for Champagne. So I will be going to France on Tuesday night and spending the rest of the week collecting juice samples from a large winery during the key stages of whole-bunch pressing.  Once we have collecting the samples, it will be back to the lab to carry-out key analysis, and then return the next day to collect more samples.

Generally most of France has being experiencing trying grape growing conditions such as late budburst, flooding rains, hail, scorching hot summers months and mostly recently weather conditions conducive to mildew and grey rot. Champagne has not been immune to this problems, and some vineyards are showing a proportion of Botrytis cinerea infection. I will be quantifying how much Laccase or by its technical name benzenediol:oxygen oxidoreductase  (IUBMB Enzyme Nomenclature E.C. has been produced by the infection. One of these easiest ways to quantify the quantity of enzymes is to measure the substrates consumed or the by-products produced.

In my experiments I will be measuring how much Syringaldazine (4-Hydroxy-3,5-dimethoxybenzaldehyde azine) has been consumed per minute of activity.  

Syringaldazine (courtesy of Sigma Aldrich)

They are many methods for measuring this consumption, at different pH, temperature, concentration and buffers.

  • Consumption of 0.5 mM syringaldazine at pH 6.5 and 25 °C (Lante et al. 2000)
  • Consumption of 1.0 mM syringaldazine in citrate-phosphate buffer at pH 5.0 (Minussi et al. 2007)
  • Consumption of 0.216 mM syringaldazine in potassium phosphate buffer at pH 6.5 and 37 °C (McNaughton 2003)
  •  Consumption of 0.01% w/v syringaldazine in sodium acetate buffer (Iland et al. 2004)

The reason syringaldazine is used because it oxidises quickly and produces a distinctive red/magenta colour change at 525-530 nm, which can be measured by visible light spectrophotometer. The increase absorbency at 525/530 can then be related to the amount of syringaldzine consumed and thence the activity of laccase in the sample.

Cuvettes of syringaldzine reaction product

Iland, P., Bruer, N., Edwards, G., et al., 2004. Chemical analysis of grapes and wine: techniques and concepts, Campbelltown: Patrick Iland wine promotions.
Lante, A. et al., 2000. Biodegradation of phenols by laccase immobilised in a membrane reactor. Process Biochemistry, 36(1-2), pp.51–58. Available at:
McNaughton, G., 2003. Enzymatic assay of laccasse EC Sigma aldrich technical documents. Available at: [Accessed September 8, 2013].
Minussi, R.C. et al., 2007. Phenols removal in musts: Strategy for wine stabilization by laccase. Journal of Molecular Catalysis B: Enzymatic, 45(3-4), pp.102–107. Available at: [Accessed September 4, 2013].

Monday, 23 September 2013

"The pure culture is the foundation for all research"

According to Robert Koch, Nobel prize winner and often considered the founder of modern Bacteriology. Koch made important breakthroughs with infectious disease such as Anthrax, Cholera and Tuberculosis. His ideas are still considered important and are used in teaching to this day.

Robert Koch (Courtesy of Wikimedia Commons)

So it it with theme of purity that I mention our new addition to the Jack Ward Laboratory, a Bassaire KV4 vertical laminar flow, which arrived today. Laminar flow cabinets are used in microbiology work to ensure a clean environment is maintained and that no external microbial contamination occurs. 

Laminar Cabinet in place in the Jack Ward laboratory 
They are quite simple in function with a fan sucking air through a high specification filter to remove all aerial contaminants. The clean air is then pushed down into the cabinet, where it is spills out over the work bench. This over-pressure of clean air reduces the contamination of agar plates, ensuring that only the organisms that you are interested in, actually grow on the plates.

We will be using the Laminar flow cabinet initially in the study of lactic acid bacteria. This year my colleague Andrew Atkinson will be investigation the growth of lactic acid bacteria that have a tolerance for low pH and high acidity. We will assessing how well they perform in the harsh acidic conditions of English Sparkling base wines. Hopefully we will be able to establish which strains perform best according to both pH and sulphite tolerance. Interestingly some of the strains we will be testing have originated in the UK, having previously been isolated by Plumpton College students Gwen McCann, David Joyce and Emma Waldron.