Background:
FACTORS AFFECTING WINE QUALITY
The quality of wine is determined by a number of interrelated variables which take effect during the fermentation process. The variables that have the most significant effect are as follows; the pH of the wine, the temperature at which the fermentation process is transacted, the alcohol and CO2 percentage present post fermentation, the amount of SO2 (sulphur dioxide) present in the solution and the wines titratable acidity.
Overview of each variable:
The pH is a measure of the amount of acids present in the solution, it differs determining on the strength of these acids and may also change depending on the other miscellaneous ingredients added to the wine with any degree of acidity. For wine specifically,
…show more content…
Because fermentation is an exothermic process (releases heat) it must be kept under constant surveillance. The temperature in which the formation process is heated controls the different tastes of wine (from fruity to artificial). For Red wines, the optimal temperature concludes at 25-300C (this includes the heat released from the fermentation process) in which yeast is fermented at its maximum and most efficient rate (because of particle movement).
Post the fermentation process, the amount of alcohol present is a main control of the taste and quality of each wine; creating preference. Fermentation (more specifically ethanol fermentation) is the process in which pyruvate (from glucose metabolism (carbohydrates)) is broken into carbon dioxide (CO2) and ethanol (alcohol), the presence of yeast and certain bacteria aids this process which occurs usually under anaerobic conditions. The chemical equation for the fermentation process is as
…show more content…
The formation of SO2 is what’s classified as a strain characteristic, and holds two purposes, the first is in the process of wine making is to inhibit the growth of unwanted yeast or bacteria during fermentation as well as inactivating certain enzymes during this process. The second purpose is to act as an antioxidant. Because of this it can protect the wine against browning and allow it to sustain its integrity for longer periods of time. When Molecular SO2 is present in wine it acts as a form of pesticide effectively killing the wine microbes. Fortunately however the yeasts that are considered desirable which are fermented have a resilience to the effects of SO2 then that of spoilage yeasts. Sulphur dioxide can also exist in an ionised form when simply dissolved into wine. In this form it has the greatest antioxidant effect. Because, instead of joining with oxygen directly, sulphur dioxide joins with other antioxidants it proceeds to remove all naturally occurring enzymes causing the wine to brown (known as polyphenol oxidases) which gives the wine a sustainability which would not be present without the sulphur
For example, incubating the samples at different temperatures would create more data points to establish an optimal temperature. From the results in the experiment in this study, it is known as temperature increases, enzymatic activity increase, and vise versa. However, what can not be observed is at what point does the increase in temperature begin to denature the enzyme, above 60°C. Furthermore, assays can be preformed to determine optimal pH, as well. From Dutta’s, and his partners, experiment it shows that there is a range where the Heliodiaptomus viduus’s lactase shows the most activity, which is between 5.0 and 6.0
The Roman writer and naturalist Pliny the Elder, in his treatise Naturalis Historia states “there is nothing more useful than wine for strengthening the body, while, at the same time, there is nothing more pernicious as a luxury, if we are not on our guard against excess.” Years before he wrote those words, wine had in fact come from humble origins outside Italy itself. Furthermore, the process of fermenting grapes goes back thousands of years, and its beginning can be traced to where the wild grown grape-vine, vitis vinifera, flourished and was actively utilized for this reason.
In this text it is saying that basically a little wine is good for digestion.
Ethanol is the only alcohol that can be drunk safely and is found in all alcoholic drinks. Throughout this investigation I am going to investigate to different factors that affect the breakdown of an alcohol. [IMAGE]e.g. Methane (HCO) + Oxygen (O2) Carbon dioxide (CO2) + Water (H2O) Aim --- I am going to investigate increasing the chain length and see what effect there is on the heat of combustion.
Investigating the Effect of Temperature on the Fermentation of Yeast To fully investigate the effect of temperature on the rate of fermentation of yeast Background Information Yeast is a single-cell fungus, occurring in the soil and on plants, commonly used in the baking and alcohol industries. Every living thing requires energy to survive and through respiration, glucose is converted into energy. There are two types of respiration available to living cells are: 1.
This lab has two sections. The first section deals with fermentation. The purpose of the fermentation lab is to alter 5 different independent variables (temperature, acid ph, alkali ph, enzyme concentration, and substrate concentration), to learn about their effects on the ongoing process of fermentation.
The effect of a change in PH on enzymes is the alteration in the ionic
The Effect of pH on the Activity of Catalase Planning Experimental Work Secondary Resources Catalase is a type of enzyme found in different types of foods such as potatoes, apples and livers. It speeds up the disintegration of hydrogen peroxide into water because of the molecule of hydrogen peroxide (H2O2) but it remains unchanged at the end of the reaction.
...the corrosion rate, then the lower the pH level is, the quicker the corrosion rate would be. This will happen because if the pH level of a liquid is lower, the hydrogen ions will consume the electrolytes, hydrogen ions are also being consumed and the element starts corroding faster.
Main principles to follow in good wine and food matching are compliment or contrast. In which you have to identify the food and wine key elements, like flavour and texture, as well as sensory components to make a better balance between the two. Physiologically, humans have taste buds that give us an ability to perceive five primary taste sensations in the mo...
Analyze and compare the Old World Wine Industry to the New World Wine Industry (please note: you must show evidence that you conducted two separate industry structure analyses). Which of the two industry environments is more attractive for incumbents (those competing in that industry)? Why?
Lactic acid have more growth requirements than then normal bacteria since it was evolved in nutrient-rich environments. Lactic acid bacteria have diverse mechanisms for creating the energy needed to support and sustain biological activities. The availability of organic acid in the fruit can be important in allowing growth and metabolism. As lactic acid bacteria have the ability to produce large amount of acids, they often inhibit the development of other bacteria in juices and are able to cause their own autolysis. Excessive clarification and pre treatment of the fruit during the process of sending the fruit to the market which removes many of the natural yeasts and flora. The chemical compsition of juice also affect the rate of fermentation. Fruits generally tend to contain sufficient substrate (soluble sugars)that allow for the yeast and bacteria to fermented , so it can be said that because the fruits used did not show a very high increase in acidity it did not provide a sufficient substrate for the lactic acid bacteria that is present on the fruit to be used for fermentation.Temperature has an impact on the growth and activity of different strains of yeast. At temperatures of
The most important alcoholic fermentation in industry is wine. It is produced by fermentation of fruit juice. Beer or ale is also one of the important alcoholic fermentation that is produced by fermentation of malted grains and distilled beverage, produced by concentrating alcohol from fermentation by distillation.
Initially, before any NaOH is added, the pH of H2C2O4 .2H2O is low because it contains mainly H3O+. The starting pH will, however, be higher for a weak acid, like H2C2O4 .2H2O, than for a strong acid. As NaOH is added, H3O+ is slowly used by OH- because of dissociation of NaOH. The analyte remains acidic but the pH starts to increase as more NaOH is added.
Alcohol is a class of organic compounds that is characterized by the presence of one or more hydroxyl groups (-OH) attached to a carbon atom. Alcohol was unknowingly produced centuries ago when fermentation occurred to crushed grapes (Pines, 1931). In today’s society alcohol is produced for the use of household products such as varnishes, cleaning products, but is more commercially important in the liquor business. A chemical process called fermentation accomplishes the production of ethanol, the alcohol or liquor. From there, the ethanol goes through distinct processes to become the dark and clear liquors on the store shelves.