How to Monitor the Brix of Fermenting Wine Must

Brix is a measurement of the amount of sugar in a liquid. The sugar converts to alcohol during fermentation. As Brix numbers decrease, the amount of alcohol in the liquid increases. Measure Brix with a device called a hydrometer.

Instructions

Difficulty: Moderately Easy

Things You’ll Need:

• Hydrometer And Testing Jar
• Fermenting Wines
• Granulated Sugars
• Thermometers
• Record Logs And Pencil

Measuring Brix

1. Be sure the hydrometer is clean and free of oils from your fingers.
2. Fill 3/4 of a graduated cylinder or testing jar with juice. Avoid including seeds, stems, skins and bits of fruit in the sample.
3. Check the temperature of juice with a thermometer and note it.
4. With the bulb end first, place the hydrometer into the juice and give it a gentle spin with your fingers.
5. After about 5 to 10 seconds, at eye level, inspect the location of the bottom portion of the meniscus against the hydrometer. (The meniscus is very top of a column of liquid; when seen in a clear container, it almost looks like a thin lid.)
6. Record the number on the hydrometer that coincides with the lowest portion of the meniscus.

Adjusting Sugar Level in Liquid

7. To increase Brix by 2 degrees, add 3 1/2 ounces of standard granulated sugar (sucrose) to 1 gallon of juice.
8. Add water to sugar to create sugar syrup.
9. Add sugar syrup to must (juice with seeds and skins) in small amounts. Stir thoroughly.
10. Check the Brix and add more sugar to raise the level.
11. To decrease the Brix, add water, in small amounts, to dilute the must, or add low-sugar grapes. If you add water, check the acid level and make the necessary adjustments.

Tips & Warnings

• If bubbles accumulate on the hydrometer, gently spin the hydrometer. When the hydrometer floats without bouncing, record the number immediately.
• Determine the amount of alcohol the juice will yield by multiplying the initial measurement of Brix - taken before fermentation - by .6. Approximately 60 percent of the sugar will convert to alcohol during fermentation.