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total acidity

The Winemaker’s Think Tank: Vol 23 – How do I test for Acid?

Wine being checked on component saturation in laboratory on winery factory

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.

Carmenere, Cabernet Sauvignon, and Malbec Numbers

Hello Winemakers!

We hope everything is fermenting along well! Below are some numbers were able to take on the grapes yesterday. Cheers and Happy Fermenting! :)

Musto Wine Grape_Chile_1 (4)

pH= 3.55, TA= 4.27, Brix 21.5

cabsav_1

pH= 3.85, TA= 3.31, Brix =23.5

carm_1

pH= 3.95, TA = 4.25, Brix = 23.2

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.

(sources: 12)

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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