Where to start when Adjusting and Balancing Must
There are two main steps to Adjusting and Balancing Must, which consist of adjusting your Brix and adjusting your pH/TA. We’ll cover what they are, what they mean, and how to do both.
Where to start when Adjusting and Balancing Must
Firstly, you’ll need your starting numbers. You’ll have to measure your Brix, pH, and TA. To measure your Brix, you can use a Triple Scale Hydrometer. To measure your pH and TA, you’ll need a titration setup or an acid test kit, and some mathematical skills. If I lost you at math skills, don’t fret – Musto Wine Grape Company offers a wide variety of testing including pH and TA testing!
What are Brix, pH, and TA?
Brix is a measurement of the sugar content within your must. This indicates the degree of the grapes’ ripeness at harvest. The higher the Brix, the higher the alcohol content in the finished wine. To get an alcohol conversion level, simply multiply your Brix by .55. pH is the measurement of the ripeness in relation to acidity. A low pH wine is crisp and tart, while higher pH wines are more prone to bacteria growth and spoilage (3.9 pH and higher). Wine generally falls between 3 or 4 on the pH scale, with 3 – 3.4 being the average for white wines and about 3.3 – 3.6 for reds. Finally, TA is measuring acidity by volume. TA stands for Total Acidity. Usually, the higher the pH the lower the TA and vise-versa. This is not always the case though, and you may need to make adjustments to your must. Hold tight, how to do that is next!
How to Adjust and Balance Must
If you need to lower your TA, we recommend using Potassium Bicarbonate. Adding Potassium Bicarbonate to your must will reduce acidity. Make sure to add slowly, as it foams significantly. It is also recommended to add to water first, then add the mixture to your must. Under typical conditions and normal use, Potassium Bicarbonate neutralizes Tartaric Acid. It’s best used when the TA is high and pH is low, due to the fact it causes an increase in pH. It also adds potassium to the must and that requires cold stabilization. Potassium Bicarbonate can contribute to tartrate instability in wine, which is also why cold stabilization is recommended. It is also good to note that the addition of Potassium Bicarbonate will cause a reaction in the wine which will vary from wine to wine and the pH will not shift in a predictable manner. Bench trials should always be done first when attempting to adjust pH.
To lower pH, the most effective method is to add Tartaric Acid. If both TA and pH are too high, tackle the pH. The pH is more critical to the wine chemistry. This addition also requires bench testing to find the best addition.
To raise the brix, we can add table sugar to the must, be sure to dilute the sugar first with hot spring water before adding it to the must or juice. There are good formulas available to calculate sugar required based on the brix you are trying to achieve.
To lower the brix, we will add spring water to the must to “dilute” the high sugar content in the must or juice. Just beware there is a limit on how much water you can add to a must or juice before you reduce the wine quality. There are also good formulas for this adjustment too.
For exact measurements and instructions, follow the directions on the manufacturer’s packaging, contact a winemaker at Musto Wine Grape Company for assistance, or download our Full Class offering at WinemakingInstructions.com.
We’re here to help when you need it
As stated above, Musto Wine Grape offers a variety of products as well as services including testing and support. Email winemaker@juicegrape.com or call (877) 812 – 1137 to speak with someone who can assist you.
The Winemaker’s Think Tank: Vol 23 – How do I test for Acid?
What’s the Winemaker’s Think Tank?
Every Thursday we will post about a few frequently asked questions that our winemaker has answered. If you have a winemaking question you would like to have answered, please email us at support@juicegrape.com and we will try to get into next week’s post. Cheers! 🙂
How do I test for Acid?
When testing for acidity in wine, you are looking for the Total Acidity value, or the amount of acids in grams per liter of wine. While this may sound complex, it will help you in achieving a proper balanced flavor in your end product. You will need a few basic lab supplies: a test tube, a small 10ml graduated syringe, phenalthalein, sodium hydroxide. Draw a 15ml sample of the wine to be tested into the test tube. Add three drops of the phenalthalein. Swirl the drops around in the wine to mix it in thoroughly. (Note: When using sodium hydroxide, be very careful. It is a strong base that can cause burns. We suggest wearing eye and skin protection.) Using the 10 ml graduated syringe, slowly drop in the sodium hydroxide by .5ml at a time. Every drop, swirl the test tube contents to mix and observe any color reactions. Upon adding the drop, you will see an immediate color change, that will then dissipate. For white wines, you will observe a pink color and for red wines you will observe a grey color. Keep repeating the process of adding a drop, swirling and observing until the color change is permanent. The amount of sodium hydroxide used, when the color change is permanent, will give you the Total Acidity. If 6ml of Sodium Hydroxide are used, then the wine contains .6% or 6g/L of TA.
We hope this information helps with your winemaking. If you have any follow up questions or winemaking questions in general, please email us at support@juicegrape.com.
Bring On The Bordeaux! – A Home Winemaking Experience (2)
So before we start going into how our wine is doing, we wanted to outline some winemaking terms. Here’s a mini wine vocabulary lesson.
Degrees Brix: Expresses the percentage of sugar by weight. This scale is on a Triple Scale Hydrometer. Measuring the Brix by using a hydrometer will help you determine the level of alcohol you wish to produce in your wine.
pH: This is the potential Hydrogen ion. The pH scale spans from 0, representing extreme acid, to 14, representing an extreme base or alkai. For winemaking purposes only the 0-7 scale is considered and wine should between 3-4. The more intense the wine acid is, (the lower the number) the less free sulfite is needed to afford proper protection and hence wine stability.
Total Acidity: This measurement refers to the amount of acid that is in your wine in grams/liter of percent of volume. Ideally, your TA should be between 0.65%-0.85% for white wine and 0.60%-0.80% for red wines. If the acid is too low your wine is susceptible to bacteria and spoilage. If it is too high your wine will taste too tart.
We took the must out of the cooler on 10/28 and waited for the must to heat up. Once the must started to heat up we took our measurements. The Brix were 25.5, TA was 5.985, and pH was 3.88. My pH is a little on the higher side. My TA is pretty good for a dry red and my Brix are at a great level to make a 12.5% alcohol per volume wine.
Some tips for taking your pH and TA measurements. I would suggest purchasing some type of all in one SO2, pH, and TA testing equipment. To test TA on your own can be very complicated and not very accurate. I would suggest looking into a Vinmetrica kit. They do all of the tests and it’s easy and accurate.
Also, try not to get distracted and mix up your solutions like I did. It took me 30 minutes to get the correct TA reading because I was mixing in the wrong solution. #airheadmove
Thanks again stopping by and checking out our winemaking process. The next post will concentrate on yeast, yeast nutrient, and other additives that help the wine during fermentation.
Cheers ~ CM & FJ
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