Degrees Brix (symbol °Bx) is the sugar content of the plant juice.
One degree Brix is 1 gram of sucrose in 100 grams of plant sap and represents the strength of the plant sap as percentage by mass. The function of plants is to produce sugar. Optimal photosynthesis and plant health occurs when the brix is over 12. Brix levels reflect sugar levels in the plant but they are also an indication of mineral levels and general plant health.
High brix crops have higher sugar and mineral content and higher true protein content. High brix produce is sweeter tasting and more minerally nutritious and a lower in nitrate. Phosphate and Calcium affect brix levels (Calcium to magnesium ratio) so brix levels can be used as an indicator of soil fertility. Soils producing high brix plants will also have less weed pressure and better pest resistance. Broad leaf weeds and sourgrasses grow better in soils lacking Calcium and Phosphate.
Brix measurement in pastures for beef cattle:
Very poor: <3 %
Poor-moderate: 4-7 %
Good: 8-12%
Excellent: >13 % excellent
Brix measurement
Taking Brix measurements requires a garlic press or other type of press and a portable or digital refractometer or Brix meter. Squeeze plant sap to the meter and measure the sugar content in the sap.
| Factors that influence brix levels | ||
| Factor | Influence | Description |
| Stress | Lower | Stress factors like weather changes will lower readings, i.e. the plant translocates sugars to the roots when anticipating periods of stress. |
| Droughts | Higher | Droughts can raise the reading by decreasing the water content and increasing the water content of the plant juices. |
| Lack of sunlight | Lower | As sunlight is needed for photosynthesis and sugar production, consecutive cloudy days will decrease sugar content. |
| Lack of organic matter | Lower | The lower the organic matter content of the soil, the faster the brix readings will drop following a cloudy or rainy period. |
| Night | Lower | Plants translocate sugars to the roots at night so early morning readings are lower than afternoon readings |