grapestompers - winemaking supplies and wine kits
Search Products
Shopping Truck
Home
Catalog
Winemaking Information
Specials
Customer's Corner
Contact Us
About Us
Policies
Location

Testing for Acidity in Peach Wine

Acknowledgement | Photos | References

Acknowledgement
We would like to thank Brian Shuhart for providing all the photos and the basis of the text for this page. He noticed that no one offered actual images of the entire process of adding reagent and swirling, as well as photos of the endpoint. We could not have made this page without his help.

Here is the note Brian sent::
I have only been making wine for a little over 2 years and have been blindly following recipes to the letter. Doing so, I have been creating wines that, to me, have an acid bite flavor. So I have been searching the web for a walk through process on how to test the acidity of wine that contains pictures. During my search, I came across a few forums with people looking for the same info. Since I could not find one, I recently bought a test kit from a local wine supply store, began testing, and created the attached document to share. You have my permission to use as is, or modify the attached document for your web page.

Photos
Here is a series of photos taken during the acid testing process. For this demonstration, I am using the Wine Acid Test Kit made by Crosby and Baker (Item #2716 in our online catalog), which comes with 4 oz. standard sodium hydroxide solution (0.1 Normal), 0.5 oz. acid indicator solution (phenolphthalein), calibrated syringe, test tube, and complete instructions.

I started with a 3 ml. sample of peach wine that has no additives. This is a good example of testing for acid in a white wine. If you'd rather see a blush colored wine being tested, please see our strawberry wine example

peach wine - no additives

Photo 1

Peach wine:  no additives

This is our starting point, a small 3 ml. sample of wine or must. Make special note of the beginning color.

peach wine - after 3 drops phenolphthalein

Photo 2

Peach wine: after adding 3 drops phenolphthalein and swirling a bit to mix

No real color change noted. The phenolphthalein serves as our color indicator.

peach wine - after 0.5 ml NaOH

Photo 3

After adding 0.5 cc sodium hydroxide

The initial pink color that appears when the NaOH is first added goes away after swirling

peach wine - after 1.0 ml of NaOH

Photo 4

After adding 0.5 cc more sodium hydroxide (for a total of 1.0 cc to this point)

  • left photo shows initial pink color when NaOH first introduced
  • right photo shows return to normal color after swirling
peach wine - after 1.5 ml of sodium hydroxide

Photo 5

After adding 0.5 cc more sodium hydroxide (for a total of 1.5 cc to this point)

This photo shows that the color still returns to normal after swirling.

peach wine - after adding a total of 2.0 ml of sodium hydroxide

Photo 6

After adding 0.5 cc more sodium hydroxide (for a total of 2.0 cc to this point)

This photo shows that the color still returns to normal after swirling.

peach wine - after 2.5 ml of NaOH

Photo 7

After adding 0.5 cc more sodium hydroxide (for a total of 2.5 cc to this point)

  • (left) The initial pink color change is growing. We must be getting close!
  • (right) after much swirling, the color finally goes away. Be careful to add the NaOH more slowly now.
peach wine - endpoint has been reached

Photo 8

After adding 0.5 cc more sodium hydroxide (for a total of 3.0 cc to this point)

The pink color change becomes final. Swirling no longer makes the color go away.

OK - now that we've successfully found the endpoint of our acid titration, let's do some quick math to discover the acid level of our wine.

According to the directions that came with the acid test kit, we multiply the amount of sodium hydroxide used (in ml) by 0.25 to find out the percentage of acid or T.A.:

3.0 ml NaOH
X   0.25
0.75 %

WARNING: All acid test kits are NOT the same; please refer to the instructions that came with your kit to determine the correct mathematical formula to use to arrive at your calculated acid level.

Since I personally like my sweet wines to have an acid level between .55% - .65% I will want to lower the acid a bit to get it to my desired taste. Please understand: Everyone has a different taste or preference for acid in their wines. Discover what yours is based on the type of wine you are making (sweet vs. dry, red vs. white, etc.) then aim for that target acidity in your future wines.

If you do need to make an adjustment based on your test results, here's a page that explains how to raise and lower wine acid levels.

See our page that shows an acid test being done on a strawberry wine. Strawberry is more of a blush wine, so the colors you will see on that page are bit different than the peach photos you just saw.

Further Reading on this topic
Clicking on any of the reference links below will open a new browser window: