Sugar content is measured in degree Brix.

Brix values depend on :

1. Varity of grapes
2. Nature of the growing season

For wine grapes the Brix value of grapes at the time of the harvesting ranges in between of 19-25 Brix.

For table grapes the Brix value of grapes at the time of the harvesting ranges in between of 14-20 Brix.

<aside> 👀 Grapes season has 120 days out of which 90 days it is sour (then all the acids get converted to sugars)

</aside>

<aside> 👀 Unripe grapes – 3.1 pH

Ideal grapes – 3.4 pH

Too ripe – 3.8 pH

Low sugar level and poor taste – 4.0 pH or above

</aside>

• For red wines, the optimal pH range is 3.2-3.6.
• If the pH is low, the wine will have a tarter taste to it.
• For white wines, the best range is 3.0-3.3.
• A high pH indicates that the grapes are too ripe or that the soil consists of too much potassium. In this scenario, the wine would likely have a flat taste.

Nuclear Magnetic Resonance

• NMR (Nuclear Magnetic Resonance) is a spectroscopic method that can be used to determine the sweetness of fresh foods. NMR can also measure sugars like glucose, fructose, and sucrose.

  NOTE: {NMR is lab technique & not available as sensor}

  

• NMR is expensive.

Electronic Tongues

An electronic tongue is a combination of several components that function in harmony to provide accurate data analysis and interpretation. These components comprise sensors, data acquisition systems, multiplexers, and a data analysis system [32]. Figure 1 shows a typical experimental setup with an electronic tongue system. First, it makes use of a sensor or a sensor network whose main objective is the interaction with the liquid or substance being analyzed [33]. There are many kinds of sensors that are normally associated with the kind of analysis and interaction with the substance to be analyzed [34]. Typically, liquids are monitored using a variety of sensors, including, but not limited to, optical, electrical, biosensors, electrochemical, and gravimetric sensors. That being said, electrochemical sensors—specifically potentiometric, amperometric, and voltammetric sensors—are the most frequently utilized sensors in electronic tongues.