Before explaining the preparation method of raisins, we will study the items which have a
hand in the quality of this product. These issues which are related to the color of raisins and
their flavor follow the type of used grapes and the degree of its ripeness which means the
amount of raisins sugar and finally raisins preparation method.
a. At picking time of raisins grapes: To produce raisins, sugar amount of the single grapes
considering the ratio of grapes juice concentration to its acidity, should be between %21 and
%33, so one should proceed to pick the crop at the end of the season, the grapes that are
collected before complete ripeness, has a relatively high amount of acidity and so will cause an
undesirable product of raisins.
b. Raisins color: The color of the raisins is related to its preparation method, i.e. if, as we will
see later, grapes are placed in an Alkaline solution or are faced to Sulphur smoke, the color of
the raisins after drying will be green or yellow, and if a single grape drying is implemented
without Alkaline solution, the produced item will be red or dark brown.
c. Raisins flavor: This characteristic is more related to the method of drying and raisins
variety from the point of its being seeded or seedless and the kind of used heat reference. In
addition to three mentioned factors, other factors which are different in different kinds of
raisins meddle with its quality. These factors include:
1. The size of the single grape: Largeness or smallness of a single raisin is related to largeness or
smallness of a single grape, and this largeness is due to regional factors and vineyard soil type
and the kind of the grape. But the most important factor which has a hand in the size of a
single raisin, is the product amount of the vine shrub. More the amount of the base product is,
smaller the single grape will be. So, more than normal fruit in a shrub not only weakens the vine
shrub, but also is one of the factors in an undesirable raisins product. The concentration degree
of grape juice affects the weight of the single raisins as well, i.e. more the amount of its dried
substances comparing to the available water in a single is, heavier it will be.
2. Raisins color: The color of raisins should be uniformed and limpid, the blurred color of
raisins and also different colors in a pack of raisins will cause a little value and undesirable good
in the market. If the grapes are dried in the sun, the color of the raisins product will be
uniformed. To obtain the best raisins from the point of color, the grapes should be completely
ripe, moreover when picking or drying the grapes, it should be with complete caution, cause if
the grape cluster is touched a lot or it is carried from place to place, Purine which is the white
powder that normally exists on all singles of grapes, will disappear and raisins color will be
blurred. In other words, the shiny color of raisins owes Purine existence. Other factor which
affects blurriness or darkness of raisins color, is the rainfall in the process of drying the grapes.
To prevent the bad effect of the rain, grapes surface should be covered with nylon or board or
any other impermeable means when raining.
3. Cleanliness of the single grape skin: One of the other factors in the quality of raisins is its
skin cleanliness. If it rains when drying the grapes, and the semi-dried grape is wet or if the
single grape is split or squeezed when picking and carrying the grapes from the vineyard to
drying location or when placing it in large wooden tray or any other dishes, so that a part of
grapes juice is extracted from the single, and contaminates other singles, some dust will reside
on the grapes, so that it will stick to the raisins' skin which cleaning it with means of washing
will be impossible as well, so the produced raisins will be bad colored and undesirable. Green
raisins if remain in Alkali solution for a long time, will have increasing number of cracks on it,
some grape juice will come out of these cracks, and it will cause a sticky raisins skin, so the air
dust will stick on raisins skin.
4. Softness or hardness of the raisins: A desirable raisin should be soft and carnal. The skin of
raisins which belongs to unripe grapes, will be full of flexures and hard and like a piece of
leather to the teeth. Although softness or hardness of the raisins are partly related to grapes
variety, preparation method and its moisture amount meddle with raisins softness to a great
deal as well.
5. Moisture amount of the raisins: If raisins after being dried and washed, has more than %18 of
moisture, it will be contaminated, and if the moisture amount of is %5 or less, it will have an
undesirable flavor. The most appropriate moisture amount for raisins is about %15 or a little less than that.
