December 13, 2016
What is Brix?
As gardeners, we strive to grow a delicious, nutritious, pest-free harvest. For the scientifically-minded, there are many measurements we can use to help us along the way, such as pH and PPM. (I like this pH meter and this PPM meter.) However, there is one measurement that many gardeners overlook: the brix. Increasing this one measurement will improve the flavor, nutrition, and shelf life of your produce. It will also keep pests at bay.
Increasing your brix will improve the flavor, nutrition, and shelf life of your produce. It will also keep pests at bay.
Brix measures the total dissolved solids in the sap of a plant, which includes sugars, organic acids, vitamins, minerals, amino acids and phytonutrients. The higher your brix value, the sweeter and more nutritious your plant is. Brix has traditionally been used in the wine, sugar, carbonated beverage, fruit juice and honey industries. However, brix can be used with any crop.
Refractometer and fresh beets
Brix values can be measured with an instrument called a refractometer, which measures the refractive index of a liquid. A couple drops of sap or juice from the plant is squeezed onto the tool. When light strikes the carbohydrates, salts, and molecules in the liquid, it bends or refracts. The more dissolved solids there are in the liquid, the greater the refraction, and the higher the brix value.
The higher the brix level, the sweeter and more nutritious your plant is.
If the fruit, vegetable, or leaf does not produce juice easily, the best way to extract it is to use a mortar and pestle to smash them and then strain it through a mesh screen onto the instrument. You could also use a garlic press.
Dr. Carey Reams, a leader in high brix gardening, developed a chart of the poor, average, good and excellent brix levels in a variety of fruits and vegetables. By using this chart in conjunction with a refractometer, you can judge the produce you grow and buy. Armed with these tools, you can find the highest quality farmers to buy from, or push your own garden to new limits.
Refractive Index of Crop Juices.
You’ll find that produce from the grocery store is consistently on the mediocre side of the chart. (And we wonder why kids don’t like to eat their veggies.) In fact, our taste buds are an even better tool than the refractometer for measuring sugar content and nutrient density in our food. Sugar and mineral content are responsible for the sweetness tingling your taste buds, and if you start tracking the food you measure, you’ll find the tastiest, most nutrient-dense fruit and veggies have the highest brix levels.
Low brix values mean poor nutrition, which leads to pests.
Low brix values mean poor nutrition, which leads to pests. Pests are nature’s clean-up crew. They ensure natural selection in plants. Only the strong survive. Plants with a brix value over 12% are much less likely to have pest issues, if they have them at all. It’s only when a plant is weak and sick that bugs attack to clean up the mess. When a plant has deficiencies, simple sugars and incomplete proteins leak out to the surface of the leaves and stems, drawing the bugs in for lunch.
There is a story of two farmers whose fields were right next to each other. One farmer took care of his soil so that his brix levels were high, and the other one didn’t. One terrible year, an infestation of grasshoppers attacked the farmer’s crops who had the low brix. If he stood in his field, swarms of grasshoppers swirled about him. However, if he took just a few steps over to his neighbor’s field, there wasn’t a grasshopper to be found. The farmer with the high brix levels had such healthy crops that the grasshoppers barely noticed them.
Fruits and veggies with high brix levels will not rot and mold. They simply dehydrate.
Not only will your harvest be better for you, but it will last much longer. Fruits and veggies with high brix levels will not rot and mold. They simply dehydrate. This is news to most people who are used to grocery store produce going bad within a few days of buying it. It may lose enzymes and vitamins with time, however the mineral content remains the same. Even if you can or freeze your produce, you will still gain the same exceptional nutritional benefit a year later.
Higher brix levels also mean your plants will have a lower freezing point, which means they will be tolerant of extreme temperatures. Outdoors, this can be helpful when dealing with first and last frost.
Higher brix levels also means your plants will have a lower freezing point, which means they will be tolerant of extreme temperatures.
Now that you see the value of high brix levels in your fruits and veggies, you’re probably wondering how to get those higher levels. As always, it starts with the soil.
How to Increase Your Brix
The key to increasing your brix levels is to increase the mineral uptake so the plants can produce more sugars. You do this by focusing on building your soil so that it is full of organic matter, beneficial bacteria and fungi, and the proper nutrient ratios. It can take 4-5 years to build truly healthy soil. For raised beds and containers, you can build a soil with the proper amendments that will do the job quickly.
A simple soil recipe would be to mix 1/3 compost, 1/3 peat or coco coir, and 1/3 vermiculite as your base. Then add beneficial microbes, and food for those microbes. Earthworm castings, mycorrhizal inoculants, compost teas, humus, amino acids, humic and fulvic acids, rock dust, and seaweed are the best soil additives to use if you want higher brix.
Beneficial microbes have a symbiotic relationship with plants. They attach to the roots, eat the root exudates, and then feed their waste back to the plant in a form that is more readily available.
Sunlight plays an important role in a plant's ability to produce sugars. In fact, harvesting on a cloudy day can result in lower sugar content.
Sunlight plays an important role in a plant’s ability to produce sugars. In fact, harvesting on a cloudy day can result in lower sugar content, and therefore lower brix levels.
Iron uptake is also important for this reason. Chlorophyll, the green pigment, manufactures sugars during photosynthesis, and iron acts as the catalyst. If iron is readily available, plants will efficiently produce sugar. Add humic and fulvic acids to the soil to make iron more readily available to your plants.
Seaweed is excellent for increasing root mass, chelating micronutrients to make them more available, and stimulating cell division. The increased root mass offers more surface area for minerals to be taken up into the plant.
Amino acids improve the uptake of minerals, specifically calcium. Calcium allows water and minerals to be taken up easily by strengthening the stem and vascular system of the plant.
Be cautious not to give your plants too many nitrates. They burn carbohydrates and reduce brix.
Be cautious not to give your plants too many nitrates. They burn carbohydrates and reduce brix. Too many nitrates will result in large cells with thin cell walls, which attract pests. If your goal is to increase brix, use minimal synthetic, bottled fertilizers. Their salts can disrupt the soil environment and the microbes that live there.
It is not overly complicated to create the soil that produces a high brix. Following a few good soil practices will deliver a delicious reward.
This article was first published in the November 2016 issue of Maximum Yield Magazine.
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