The Importance of Brix in Cannabis Health

By Luis Cordova
Published: February 19, 2021 | Last updated: May 26, 2021 07:38:41
Key Takeaways

Using a basic tool like a brix refractometer gives growers a glimpse into the inner workings of cannabis and how well it will perform. Choosing a plant with high brix can produce the heaviest and tastiest buds when it comes time to harvest.

Sugar content in cannabis is something most home growers rarely consider. But like all plants we consume, as well as other consumables, the brix value is very important. In the case of cannabis, sugar levels within the plant are essential for healthier buds, increased THC, and a more appealing flavor. In this article we’ll explore the tools needed to measure brix, how sugars affect the plant, how brix levels can be manipulated, and understanding what different brix values mean.


What is a Brix Refractometer?

A brix refractometer is an instrument that measures sugar concentration in a sample. It has been used by the wine, beer, beverage, fruit juice, maple syrup, and honey industries for more than 150 years. A refractometer estimates the amount of light bent through a solution. The amount of bent light is converted by the brix refractometer into a readable number giving us an estimation of the percentage of sugar.

When using it to test cannabis plants, the sugars often contain other solid material like minerals, salts, and other metals in low percentages. Brix can also be used to give an indication of total dissolved solids (TDS)and overall health of the plant.


How Sugars Play a Role in Cannabis

As all growers fret over increasing yields, most will overlook the amount of sugar within the plant. Sugar in cannabis is one of the most essential nutrients to its growth processes. Sugar levels in cannabis can be one of the main factors impacting its growth and its final weight at harvest. If the plant has enough available sugar, it can distribute it, causing buds to increase in size.

All growers know photosynthesis is the plant’s process of converting sunlight into sugars. A healthy plant has high levels of sugars concentrated in its buds but will distribute sugars throughout the plant. Sugar distribution is referred to as sink strength, where the flow of sugar sinks into cannabis’s various structures. To increase sugars in the plant, growers must have the right tools to enhance and encourage sugar production.

Read also: Terpene Analysis: A Higher Level of Cannabis Quality


As the plant is growing, younger leaves will require more sugars while mature leaves need less. As simple as this may sound, the plant is going through complex competition with all parts, trying to pull sugars from wherever they can get it. The harder they try absorbing sugar, the more sugar is required to keep a plant healthy. We can calculate the efficiency of sugar conversion from sunlight by measuring simple sugars or carbohydrates from within the sap of the cannabis leaves using a brix refractometer. In other words, more available sugar you can provide to the plant will promote healthier plants and heavier yields, which can be monitored using a brix refractometer.

Cannabis plantThrough photosynthesis, cannabis plants convert the water and carbon dioxide into sugars.


How to Improve Cannabis Production with Brix

Sugar conversion is not only about sugar absorption and the ability of the plant to use light. Many different factors are at play determining the efficiency of photosynthesis. These factors include water level, soil health, mineral availability, and beneficial fungi.

By increasing sugar production, growers can encourage nutrient uptake and produce fatter buds. There is a large array of sugar supplements that can help to increase sugar absorption to the right areas of the plant. This includes branded products as well as blackstrap molasses. Adding these products closer to pre-flowering can effectively increase sugar distribution throughout the plant.

Boosting Sugar Levels

Although supplementing sugars is beneficial, other methods can aid as well. The most common method to boost sugar production is by trimming the leaves. Commonly referred to as defoliation, sugar production is sped up and helps redirect sugars to the most needed parts of the plant. However, defoliation is a delicate balance of removing not too many leaves as this can slow down photosynthesis, increase stress, and inhibit growth. A simple method is to trim or remove leaves from the third node down. All cannabis plants don’t directly absorb sugar but produce it themselves.

Through a series of complex metabolic processes in combination with optimal environment can lead to bigger yields. To get bigger yields it is important to stimulate cannabis to produce more sugars. By stimulating sugar production cannabis becomes stronger and better able to fight off disease. Increases in sugar production can also improve the flavor and THC content of the flower. It is easy to test sugar levels of your plant by measuring sap with a brix refractometer. Doing so helps track the cannabis plants health and feeding practices.

Read also: Starting Off Right: Feeding Cannabis in the Vegetative Stage

To stimulate sugar production, growers can use a good light source that is suitable for your grow space. Use nutrients at adequate levels for each stage of the plant’s grow cycle, with veg and bloom boosters. Use a watering schedule that suits your growing environment. Control the growing environment such as temperature, air flow, and humidity and have a clean grow space to reduce pest and fungi, which will reduce stress. Also, trim cannabis appropriately during the vegetative and flowering stages.

Hand holding a brix refractometer.Average brix levels for cannabis are typically in the range of 12-20.

Understanding Brix Readings

Now we understand how plant sugars can improve cannabis yields and how a brix refractometer can tell us the amount of sugars in the plant. The last question to be answered is what a high and low brix reading means. Low brix readings for cannabis are in the range of 0-12 and usually indicate high nitrates, poor nutrient density, and an overall unhealthy plant. Nitrates are usually distributed in water with higher nitrates concentration. This means sugars are lower. That may cause a decrease in bud growth and an unhealthy plant.

A watery brix reading also indicates other mineral deficiencies that can increase insect attack and disease. Low brix further indicates more stress for the plant. Low brix tells growers a change to the growing conditions is needed and may show pest control measures need to be taken. Average brix levels are typically in the range of 12-20. An average brix level tells cultivators the plant is doing well. It will also allow you to slowly increase brix levels to produce the tastiest and heaviest yields.

Higher Brix Measurements

High brix readings are typically in the range of 20-30. A high brix reading shows a plant at the peak of its health. These plants may grow faster, weigh more, and have higher quality buds compared to others. For breeders producing seeds, higher brix indicates high-quality seeds will be produced. These seeds typically germinate better, grow stronger, and give the best value to the buyer.


Brix is an easy method of understanding how your plants are performing during the grow. Brix gives the grower an indication of how healthy or unhealthy the plant is. It allows growers to get a glimpse into the future of the plant’s lifecycle. It is important to have your brix level at 12 to ensure the plant is poised for a good yield. By adding supplements to the watering schedule, the plant can easily go above a brix level of 20 — the most desired level on the cannabis market.

By using a simple brix refractometer, growers can expect the heaviest and tastiest buds they have ever produced.

Read next: 6 Steps to Great Big Cannabis Buds


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Written by Luis Cordova | Plant Biotechnician, Pharmaceutical Scientist

Profile Picture of Luis Cordova

Luis holds a M.S. in Plant biotechnology and Pharmaceutical Science. He is a long-time cannabis grower He has put his focus on breeding cannabis and development of organic soils for tropical regions. He loves how much the industry has grown and changed. He hopes to pass on new and old knowledge to all growers across the world.

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