Present on the stalls from August to October, grapes is appreciated by everyone for its freshness and sweet flavor. Problem: it is very sensitive to heat and humidity and at room temperature, the grains soften and can mold in a few days.
Conservation of red or white grapes: how to keep grapes for a long time?
Very rich in water and sugar, grapes are a particularly sensitive fruit and difficult to keep Because he “breathes” quickly after picking. This means that its cells continue to transform sugar (glucose, fructose) into energy in the presence of oxygen, by producing co₂, which accelerates its aging. In parallel, the grape loses water by evaporation; As a result, its grains soften and scatter.
“Two things are responsible for this phenomenon: on the one hand the temperature and on the other hand the light “Explains Ronaldo Oyama, organic market gardener.
- The cold, by slowing down the fruit metabolism, limits this process. Indeed, at low temperature, the Enzymatic reactions of cellular breathing Take place slower, the grapes therefore consume its sugars less quickly and ages less quickly. It also reduces thewater evaporation Through the fine skin of the grains and dries up slower.
- Light, on the other hand, slightly stimulates cellular breathing and accelerates oxidation: the grains therefore brown faster.
To keep your grape optimally, it is therefore important to place it out of heat and light. Ronaldo Oyama, organic market gardener.
Should the grapes be put in the fridge and how long can you keep it then?
The refrigerator is therefore a good way to extend the lifespan of a freshly bought grape, when you do not want to consume it right away. “The cold slows down the maturation of the grapes, and limits the development of certain fungi. Placing its grapes in the refrigerator therefore allows it to be kept longer,” confirms Ronaldo Oyama.
To do this, the market gardener recommends Place it in a paper bag – and not in plastic which would prevent the grapes from breathing – and in the vegetable tray of the refrigerator.
Be careful however, it all depends above all on the degree of maturity from which the grapes were bought and the day when you want to consume it: if the grapes are “green” and you want to eat it the next day, it is better to leave it in the open air so that it ends up ripening a little. Ronaldo Oyama.
Pour know if your grapes are ripe or not You have to be attentive to the color of its grains: the white grape is rather green when it is not ripe and its grapes yellow with maturation. For black grapes, it must be of a deep and united color. We can also linger on the roundup (woody part on which the grains are hung), which must be green but brittle.
“If you want to keep your grapes room temperatureI recommend wrap it in a nearby cloth In order to avoid too fast exchanges with air and light, ”says Ronaldo Oyama.
And we Always avoid storing clusters near apples or pears Who are large ethylene producers, a gas that has the distinction of accelerating the maturation of fruit.
Can we freeze grapes?
If he can be tempting to freeze The grapes, to be able to taste it throughout the year, is unfortunately a bad idea.
The grapes are very rich in water, which will therefore increase in volume when it is frozen: result, the thin skin of the grapes will break, and during thawing, the grain will lose all its water and will no longer be presentable. Ronaldo Oyama.
However, the grapes can also be eaten cooked, in sweet sweet dishes or in pastries (pies, crumbs). It is then possible to use grapes which has been previously frozen.
And what conservation for raisin?
When it is dry, the grape is kept much more easily that fresh, because it contains very little water. The ideal conservation conditions are the same as for all dried fruits Namely in an airtight container (glass jar or metal box for example), in a cool, dry and sheltered location. It can be kept six to twelve months without problem.