The combination of sweetness and sourness (acids with sugars) occurs in nature in almost all of the best fruits. Indeed fruits which do not have this ‘antagonism’ are usually flat and uninteresting. Being so fundamental a quality and one fairly simple to measure, it is often the main scientific criterion of breeders when they wish to evaluate new varieties of fruit or tomatoes. It may not be true to say that a tomato with both plenty of acid and plenty of sugar is always good eating, but it is safe to say that if it lacks these elements it is certainly not.
What is Sweet-sour and How Do You Use It? Photo Gallery
The combination of acidity and sweetness in fruit dishes we accept as such an everyday matter that it passes without remark. Indeed, we simply regard it as sweetening something which is over-sour, and usually the balance is tipped well on the side of sweetness. However, if ‘sweet and sour’ is mentioned in connection with meat or fish dishes, many people think only of Chinese food. It is true that savoury sweet-sour combinations are important in the East, but for a long time back, certainly in Roman times, they have also been important in the West. Italy, Germany, Austria, Scandinavia and Holland have many sweet-sour dishes, and in the Middle East they are popular too, especially in Persia where there are many combinations of meat with fruit.
We have, of course, been speaking about a dominant effect, but the combination is also important as a background. It is a common practice with some cooks to make dishes a trace sweet with sugar and then adjust back to ‘neutrality’ with lemon juice. They say that this enhances the flavour of the whole. It is a matter of opinion. There are certainly many meat dishes containing naturally sweet vegetables, such as onions or carrots, which need to be adjusted with a few drops of lemon juice, and this is certainly a sweet-sour background.
Finally, I must mention the delicious effect of mixing sweet-sour combinations in the mouth rather than in the dish. A spoonful of sour cream in bortsch would be an example of this, as would be serving a sour sauce with a sweet or slightly sweet dish.