Brix:  What is it and how is it important?

Brix (°bx)

Relative density scale indicates the percent of sucrose by weight (grams per 100 millilite of water) in a solution or juice of a plant measured in degrees Brix (ðBx). A refractometer is used for measuring solids dissolved in water; it corresponds directly to the refractive index scale. A refractometer allows you to accurately measure the percentage of sugar or Brix in any liquid with just 2 or 3 drops.

Using a Refractometer

You can use a refractometer on all plants, vegetables, flowers, trees and lawn. Experiment for proper brix levels for the type of plant you are testing. Very simple to use. Just press a liquid sample of either the fruit or the leaf down against the glass plate. Point it toward a light source and look through the eyepiece to view the reading. A refractometer is a “must have” for anyone growing their own food and/or wants to know what the Brix levels are for their fruit trees , plants, vegetables, anything that grows.

For most vegetables , flowers, etc, a good Brix level to maintain is 18 or higher (get to 22 and you will be singing).

A refractometer is a tool you can use to measure the health of your plants re their sugar content, re their mineral levels. Often used to measure the dissolved sucrose in a liquid it gives you the Brix reading. A refractometer was invented by a cook/scientist ( Ernst Abbe: Invented the first refractometer, and many other devices) who wanted to know how sweet his fruit was such as an apple. Gardeners soon found out that you can not only measure the “sugar” levels of wine and beer (it is used mainly for beer or wine making) but also fruit, vegetables, lawns, flowers, and you can also measure the plants levels of minerals and complex carbohydrates.

A Refractometer device measures sugar concentration in plants both from the fruit and it’s leaves. Refractometers are also used for  drug diagnosis of what’s in your blood, and used in gemology to see what it is crystals, etc, are made of, used in veterinary medicine to determine what a disease is doing, used in aquariums upkeep to determine the right pH of the water, and for farming (in wine making, and beer making). It is a tool that can be used to test the health of your crops by showing you what the Brix  level is of the fruit or plant or vegetable you are testing.  A refractometer uses refractive light passing through plant sap or fruit or vegetable juice to take a reading of nutrient (sugar, mineral, carbohydrates)  levels. The higher the Brix, the healthier, disease and pest free (more resistant) is the plant; the higher nutritional (dense) value the plant will have. 

A low Brix means that your crop will not grow to its potential due to some external limiting factor, such as:  low levels of nutrients, low mineral levels or mineral imbalance in the soil which allows weeds to grow and compete for food and light,  low calcium content in the soil or deficiency in boron and other exotic minerals, which usually indicates other problems with the translocation of sugars. This happens when you get a low Brix reading in one part of the plant and a higher Brix reading in another part. For gardeners, a refractometer will tell you if your plant has watery cells. Watery cells means the plant is very low in the sugars it needs to function. You want your plants to have lots of dissolved solids like sugar.

Using a refractometer on a regular basis to keep track of your plants’ health over a period of time will help you to determine problems before they crop up, as you can tell if what you are doing is working or not.

If you test your tomato plants with a refractometer and you notice a declining Brix reading, then you can correct it by either foliar applications or soil applications to raise it before it translates into a serious problem. Healthy plants will naturally have a very high Brix reading.

Higher Brix equals higher sugar level and the sweeter the fruit will be.

Higher Brix equals higher minerals. Higher minerals means less diseases and pests.

Higher Brix equals higher complex carbohydrates. Insects can’t eat complex carbohydrates (but they do love simple carbohydrates!). Plants with high Brix levels are no longer “food” for insects. Insects often spread diseases.

A plant with a high Brix reading means a few things to me:

1. The higher the Brix the higher the complex carbohydrates

2. The higher the Brix the higher the minerals. A fuzzy line between the dark and light not only tells you the Brix level, but the fuzzier the line the more blend of minerals you will have (its called the Fuzzy Line rule).

3. The higher the Brix the higher dissolved solids.

4. The higher the Brix the less the pests

5. The higher the Brix the less diseases it will have.

6.  A plant with a high Brix reading is that way because the soil is alive with Mycelium. The Mycelium provides all plants with the minerals they need.

Brix levels are important to know if you want to be able to detect problems before they become an issue. Knowing that a Brix level is low, low enough to attract insects, is an important warning sign to know and one can use this information in order to control and eventually not have this problem at all.

Understanding that low Brix levels usually means trouble to your plants and to you is one that has taken me over 55 years to learn and so now I pass this knowledge to you. Living in such a wonderful year round climate (that Malibu has), one can see from my location that I have developed into a very specific niche and within that niche grow only specific plant varieties and have done so forever. In Malibu, we do not have to worry about snow and our plants show it.

Using a refractometer to measure the Brix level of your plant (not the juice) will tell you how much minerals and complex carbohydrates the plant has available to it. A good gardener can tell if a plant is getting all its minerals or not by the way the plant looks, but sometimes it is helpful to have a tool that can guide you in the right direction.

You can obtain a good inexpensive refractometer by any of the following:

Go to EBay  type in Sugar Refractometer in the search box. Pick a  good analog one to start with. They come in either analog or digital. The digital usually cost more and are harder to use but well worth it once you get good at using it. You can expect the cost to range from around $50 to  around $200. If you buy it too cheap don’t expect it to last, so I would  buy around the $100 mark for an analog type of refractometer

Refractometers and charts are available from:

Pike Agri-Lab Supplies Inc., RR2, Box 710, Strong, ME 04983 (207-684-5131)

Rex Harrill, PO Box 6, Keedysville, MD 21756 301-432-2979 .

How to get a reading

First you must get the juice from either the fruit, the leaf, or whatever part you want to read. You can also use it for carrots  and other below ground crops.

This can be done by placing a small amount of the juice onto the glass and then looking through the eye piece to read the Brix level. The Brix level is the point (line) where the dark part on top meets the white solid bottom. where the two meet, you read the Brix number next to it. That’s it!

any questions

email me at

andylopez@invisiblegardener.com

andy Lopez

Invisible Gardener