additives-in-winemaking

Demystifying additives in winemaking and viticulture

Growing awareness of the impact of food on wellbeing is a good step forward in terms of public health. However, there is growing concern over whether it is problematic to consider all preservatives and additives in general as harmful. An unfortunate byproduct of growing public concern has been that unscrupulous charlatans are more able to sensationalise objectively harmless additives and capitalise upon unsuspecting consumers. Admittedly there has in the past been genuine scandals creating cause for concern, the 1985 diethylene glycol scandal an example of one. With that being said, robust regulatory systems, regular review of the science, and a large amount of data now required pre-approval, should give consumers confidence that they are buying wine free of harmful additives. Winemakers are well aware of the stringent regulations they are subject to and have a good track record of compliance. Modern consumers expect to purchase quality products (albeit this is a somewhat subjective measure) which are free of spoilage and have a long shelf-life. In order to achieve a consistent quality product in a commercially viable manner, winemakers have available to them a number of harmless additives. Whilst there may be over 60 additives available to winemakers, the reality is that only a handful are used in often small, measured quantities. In this article, I hope to demystify common additives in winemaking and provide a more nuanced exploration of what these ‘additives’ are, how, why, and in what quantities they are used, and to discuss their harmless nature.

cork-winemaking

Cork in winemaking: history, production, taint and Diam

As early as the fourth century Egyptians are believed to have used cork for fishing buoys; however, there is no consensus as to when the first cork was used to stopper a bottle of wine. Corks have been found in Roman shipwrecks dating from the fifth century BC, though it does not appear to have been the usual method of closure. After the fall of the Roman empire, global trade vastly decreased, between 500 and 1500 cork farmers from the Iberian Peninsula struggled to their products and cork gradually disappeared. In the 17th century cork reemerged and for almost the last four centuries virtually every bottle of wine has been sealed using a cork. However, since the 1970s alternative solutions began to emerge and the cork monopoly looked to be in question. The cause of the onslaught, amongst other things, was a chemical compound known as TCA, otherwise known as cork taint. Despite the growing presence of alternative closures, millions of winemakers drinkers around the world refuse to budge. In this article, I will explore the history of cork, it’s production, faults and the future.

Phosphorus in viticulture and winemaking: an exploration from soil to bottle

Besides that which is essential for photosynthesis, namely carbon dioxide, water, and sunlight, grapevines also require a range of nutrients to grow, survive and prosper. These nutrients are split into two groups depending on the scale of requirement, macro and micronutrient, the former being those required in larger amounts. Phosphorus is essential for plant growth. It is a component of cell membranes and DNA and plays a vital role in photosynthesis, the movement of sugars, and carbohydrate storage within the vine. Deficiency of phosphorus in vines can result in reduced vine vigour and yellowing of the interveinal area of basal leaves. In extreme cases, this may be followed by early defoliation of these leaves. Poor bud initiation and fruit set may also be observed. In this article, I will explore phosphorus in viticulture from soil to bottle.

cap-management-winemaking

Cap management in winemaking: punching, pumping and considerations

In order to make wine, grapes must undergo alcoholic fermentation. In the case of red wine, the vessel used for fermentation, dependent upon winemaker preference, will also contain the skins, seeds and stems. During fermentation, yeast produce carbon dioxide, this carbon dioxide causes grape solids to rise creating what is referred to as a cap. The cap can present a number of risks, a combination of acetic bacteria, the warmth of fermentation and oxygen could easily convert a vat to vinegar. For this reason, winemakers must manage the cap. Cap management also forms part of the winemakers desired stylistic preference. Tannins, anthocyanins and flavour compounds, all essential to a wines character, are found in large quantities in grape skins and so varying methods of cap management will greatly alter a finished wine. Fail at cap management, and you may well have failed the wine.

nitrogen-viticulture

Nitrogen in viticulture and winemaking: an exploration from soil to bottle

Besides that which is essential for photosynthesis, namely carbon dioxide, water, and sunlight, grapevines also require a range of nutrients in order to grow, survive and prosper. These nutrients are split into two groups depending on scale of requirement, macro and micronutrient, the former being those required in larger amounts. Nitrogen is the most abundant soil‐derived macronutrient in the grapevine. It plays a major role in all processes and a significant amount of nitrogen is essential for normal vine growth. In viticulture a nitrogen deficiency may affect key metabolic functions and retard shoot development and bunch formation. In winemaking a shortage of yeast assimilable nitrogen can result in problematic fermentations. In this article I will explore nitrogen in viticulture from soil to bottle.

potassium-winemaking

Potassium in viticulture and winemaking: an exploration from soil to bottle

Besides that which is essential for photosynthesis, namely carbon dioxide, water, and sunlight, grapevines also require a range of nutrients in order to grow, survive and prosper. These nutrients are split into two groups depending on scale of requirement, macro and micronutrient, the former being those required in larger amounts. Potassium is the second most abundant mineral nutrient in plants and has a number of roles. It is associated with the movement of water, nutrients and carbohydrates whilst also helping to regulate stomata and supporting enzyme activation. A deficiency can reduce yields, fruit quality and increase susceptibility to disease. Too much can cause a finished wine to lose acidity. In this article I will explore potassium in viticulture from soil to bottle.

Oak in winemaking; dissecting the origin, selection and science of barrels

For over 2000 years oak has been a fundamental component in the production, maturation and transport of wine. First used by merchants as a vessel for transporting finished wine, its capacity to transform the liquid within was arguably a serendipitous byproduct of its initial purely practical use. Decisions associated with the preparation and use of oak in winemaking are arguably some of the most influential in defining style, be that regional, site-specific or that of an individual vigneron. Often under-appreciated, the journey of the oak barrel from forest to cellar reveals an intricate and complex story, one of nature, craft and science.

Minerality in wine: exploring the topic from the ground up

As a descriptor, minerality didn’t crop up in the wine industries lexicon until the late 80s. In a recent Decanter article Prof. Alex Maltman recalled writing his first piece on the topic a little over 15 years ago. Maltman posits the term to be of ‘pragmatic usefulness’ despite there being no clear consensus on what it actually means. We wine-lovers are relentless in our indulgent pursuit of translating perception and sensation of wine in to sometimes simplistic terminology. Vast may our parlance be, minerality is arguably amongst the most ubiquitous of its terms. Why is the topic so challenging? Is it helpful? What do we know about it? In this piece I will explore the research and piece together my thoughts.

Rotundone: putting the pepper in shiraz

The aromas and flavours associated with particular grape varieties and regional specific wines are more often than not a result of large numbers of compounds, of varying origin, interacting with one another and forming various olfactory and gustatory qualities. There are however a number of compounds (in this case sesquiterpenes) which have an individual aromatic quality associated to them. The distinct aroma of pepper so often associated with cool climate Shiraz/Syrah is the result of one of these sesquiterpenes …

Yeast in winemaking: the unsung heroes of aroma

As a 16 year old I remember working in the cold, damp warehouse of a recycled clothing store. Frequently I would find myself muttering frustratedly under my breath that I was certain the store’s customers would never give me any credit for my work and that the more glamorous store assistants would be the recipients of their gratitude. I think that if our beloved yeast could speak they would vent similar frustrations. So often we wax poetic about the beauty of soil, terroir, vineyard management and climate but less often do we give yeast their fare share of our appreciation. This article will explore in a little more detail the role of yeast in winemaking.