Soluble solids or sugar content is one of the fruits’ maturity indices. As the fruits ripens the level of acidity decreases and the level of sugar increases. However, the theory is not true to all fruits. You may never consider making a random check before fruit harvesting but this is very important especially in grape wine making.
Recommended Soluble Solids of Fruit at Harvest Time
| Fruit | Soluble Solids |
| Apple | 10,5-12,5 |
| Apricot | 10 |
| Blueberries | 10 |
| Cherry | 14-16 |
| Grape | 14-17,5 |
| Grapefruit | 8 |
| Kiwifruit | 14 |
| Mango | 8 |
| Mandarin | 8 |
| Melon | 10-12 |
| Nectarine | 10 |
| Orange | 8 |
| Papaya | 11,5 |
| Peach | 10 |
| Pear | 13 |
| Persimmon | 18 |
| Pineapple | 12 |
| Plum | 12 |
| Pomegranate | 17 |
| Raspberry | 8 |
| Strawberry | 7 |
| Watermelon | 10 |
Sugar content can be measured using refractometer. Read the method here.