tartaric acid measurement
To begin with, tartaric acid (otherwise known as dihydroxysuccinic acid or tartaric acid) is a colorless, odorless and tasteless crystal that has a very sour taste. E334 tartaric acid is mentioned as a food additive. Tartaric acid is found naturally in many fruits. It is especially abundant in grapes and citrus fruits. In some foods, it is combined with magnesium, calcium, or potassium. Originally tartaric acid was obtained as a by-product of the wine industry. It was mainly used to prevent the growth of bacteria in wine in vats and barrels.
Grapes.
Before the advent of simple methods of measuring acidity, pH meters were used to monitor this parameter, which led to the tradition in some countries of calling acidity pH. Grapes contain tartaric and malic acids. Their ratio varies depending on the grape variety and cultivation process. In this case, the acid concentration is determined by converting the total acidity into tartaric acid concentration. The concentration of acid in grapes ranges from 0.4 to 0.7%.
The acidity in wine can be adjusted upward as well as downward by means of an oxidation (oxidation) process. The acidity can be increased by adding various organic acids and decreased by diluting it with water or fruit juice. Of course, this requires constant and strict control of the acidity in the wine. PAL-Easy ACID 2 and PAL-BX|ACID 2 are very compact, so they can be used directly in the plantation or in the production line.
In some countries (e.g. France) the acidity of wine is expressed by converting it to sulfuric acid. The terms “pH” or “amount of alkali in acid-base titration” may also be used.
Wine contains various acids, but the most important are tartaric and malic acids. Acidity is determined by converting total acidity to tartaric acid. The acidity of wines ranges from 0.4 to 1.0%.
Approximate acidity of grapes and wines:
- Grapes (Peonies): 0.60%
- Grapes (Delavar): 0.59%
- Grapes (Kyoho): 0.47%
- Grape juice: 0.28…0.54%
- Red wine: 0.49…0.65%
- White wine: 0.50…0.73%
Applications:
Tartaric acid is used in many sectors and industries, such as:
- In the food industry as a preservative and flavoring agent.
- Cosmetic Industry: E334 is a component of many face and body creams and lotions.
- In the pharmaceutical industry: Used for the production of various soluble medicines, the manufacture of soluble effervescent tablets and other medicines.
- In analytical chemistry: For separation of racemates of organic substances into isomers and for the detection of aldehydes and sugars.
- in the construction industry: to retard some building materials (cement, gypsum)
- in the textile industry: dyeing fabrics.
How do we know we are using quality grapes? – Depending on technical maturity: tartaric acid content and sugar content. Technical maturity occurs when the grapes are suitable for consumption fresh or the preparation of certain types of products.
Since the tartaric acid content is high in grapes, we will measure it on freshly squeezed grape juice. We will use a PA L-BX/ACID2 refractometer from ATAGO, a tartaric acid meter, to determine the certificate. It is necessary to put a few drops of the sample on the prism so that no bubbles remain and press the “Start” button. After that a numerical value will appear on the screen – the dry %Brix deficiency reading. In order to find out the content of tartaric acid in grapes, it is necessary to dilute the sample available on the prism with distilled water on the funnel (about 10 ml) and press “Start” button. Then we see the second numerical value – grape acidity (g/100 ml).
grape acidity
Acid is as basic a structural part of wine as alcohol or tannin. The first sip is always a test of a wine’s strength or seriousness. And acidity is responsible for that first impression. It comes high and low, crisp and tangy, attractive and exaggerated. But unlike people, wine still has a second chance at a first impression of itself…
Acidity is directly related to the wine’s sense of freshness. Expressive acidity is vibrancy, freshness and speaks to the tasters’ language, even the nervousness of the wine. Low acidity is lifelessness, dullness and a sense of excessive sweetness. Too much acidity is associated with the wine being harsh, harsh and aggressive, burning, lack of grape maturity or insufficient winemaker ability. And the golden mean between all of these options is what we call a balanced wine. Let’s take two wines with the same sugar: let the first be strong acid and the second be low acid. The first wine looks fresh, balanced, and not too sweet under the specified conditions. The second is strong, unheated, and its acidity will be more like the components. That’s why acid is so important in achieving a balanced wine, balancing out the sweetness and alcohol that are responsible for that first impression.
Where does the acidity in wine come from? Of course, from the amount of acid in the grape berries. During ripening, the initially high acidity of the grapes gradually decreases as the berries accumulate sugar. In this process the main roles are distributed: firstly, the genetic properties of each particular grape variety, and secondly, the climate and the terrain in which these grapes grow. The simplest relationship between grapes and terroir is as follows: hot climate and lots of sunny days – high alcohol – high sugar content in grapes – low acidity of wine. Correspondingly: cool climate – moderate alcohol – medium to heavy grape sugar content – heavy wine acidity. Thus, southern winemaking regions are low acidity wines, while northern or just cool regions are high acidity wines. But, of course, acidity can be controlled: you can harvest grapes with green, immature, unripe and high wine acidity. You can pick grapes with covers or flowering grapes and get a wine with low acidity. The greatest acidity of white wines is in the natural order of things – white grapes are more likely to grow in cooler regions than reds.
All grape varieties and their wines can be divided into three categories – high, medium and low natural acidity. High: red varieties – Pinot Noir (all Burgundian), Carignan, Nebbiolo (Barolo and Barbaresco), Barbera, Sangiovese (Chianti), Saperavi; white varieties – Riesling, Sauvignon Blanc, Chenin Blanc, Melon de Burgogne, Silvaner, Trebbiano, Albarinho, Rkatsiteli as well as Champagne and young wines. Medium: red varieties – Bordeaux and Rioja, Shiraz, Cabernet Sauvignon, Tempranillo, Grenache (Garnacha); white varieties – Chardonnay from France, Pinot Grigio Low: red varieties – Zinfandel, Merlot, Carmener; white varieties – Viognier, Gewürztraminer, Muscat, Chardonnay from California.
Champagne, Sancerre (standard Sauvignon Blanc from the Loire) and Chianti (standard Sangiovese) are traditionally on this list. “Crisp” and “sonorous” are most often called Chablis, Sauvignon Blanc from New Zealand, and Albariño from Spain. But an example of high acidity and balance is Pinot Noir from Burgundy.
Pinot noir, which has red skins but white juice, often has a desaturated color, even pale. You can read the newspaper through them, using the now-legendary terminology. It does have complex aromas – reds, forest berries, underbrush, wet fur, autumn woods. But its main feature is its acidity. Pinot Noir grows mainly in the limestones of Burgundy. And red grapes grown on limestone soils and the resulting red “cold”, tart and balanced wine is a far greater challenge than a white wine grown on the same limestone soils.
Sancerre from the Loire Valley also follows in the footsteps of coarse soils. The native Sauvignon Blanc grows on limestone and flint soils near Orleans. A coastal measure rules here: summers are never too hot – so reminiscent of the proximity of the Atlantic – and winters are harsh. These conditions produce wines with moderate alcohol but high acidity. The Sancerre Sauvignon is dominated by citrus tones, especially grapefruit, and herbal notes. But the main characteristics of wines from Sancerre are acidity and minerality. “Sancerre is about minerality, fruitiness and spiciness in the glass,” says Jean-Marie Bourgeois, owner of the great Sancerre terroir. – Chardonnay is often complex and heavy, but Sauvignon is always fresh and light, floral and spicy exotic notes. Have a glass – and reach for another. It’s a win-win situation for restaurants.” The Bourgeois family has made its fortune on the gastronomic pairing of Sancerre wines with French cuisine, and it has lasted no more and no less than four decades. The acidity of a wine is the main characteristic for a successful gastronomic pairing.Acidity and salinity play well together, softening each other.The best friends of high-acid wines are seafood and cheese…
