Is there an easy way to read acid test results with red must? I heard somewhere that you can proportionally reduce your sample, then multiply your results. Is this accurate? My problem is not being able to determine color change at the right time with any degree of confidence. Suggestions?
Hi....from a previous post somewhere....maybe on here........
Subject: Re: Re: New (old) way to measure TA
Always trying to beat the system without spending $300 on equipment and not being very scientific to start with while snooping around on Winepress yesterday I found an article about T/A posted by "WineTheif," the eighth post down from the top at the following link that made a lot of sense to me.
The only trick seems to be to master the flow rate from the buret. Here's the article with the link below in case the photo does not show up in this email.
**** Here's a hint on doing acid tests on red wines and red fruit wines.. It is really hard to look through the glass of the test tube and tell if the color has changed on red wines.. It is easy with white and amber color wines but it is hard to detect the change in red wines.. So here is an easy way to look for the change. You will need your test kit and a stir stick or back end of a spoon, and a white 3x5 card or white printer paper.Lay down the blank white paper or white 3x5 card and use your stir stick to put a test drop of your wine on the cardboard or paper, before any chems are added so you have a starting point. (in my case I use the back end of a spoon to stir with and place the drops) Then add the 3 drops of indicator and stir well. Then add the first .5-CC of Sodium Hydroxide... Stir vigoriously with your stick then lift the stir stick out and put a drop next to the last drop and compare. If no change then repeat with the next .5-CC of Sodium Hydroxide., stir and put another drop on the card and compare. When you see that the color changes to grey you have reached your Acid Content..
As you can see from the attached picture of this BlackBerry wine that I just started today, it's change of color took place exactly at 6-CC's of Sodium Hydroxide.. Therefore having a TA of .60.
The test right before this one (I forgot to take pics) changed to grey at exactly 4.5-CC, so I added 3 level tsp's of Acid Blend to my 3 gallons of must (1 tsp per gallon) and stirred it in well. The test pic attached here is the next test taken after this addition..
This test is the 5th test on this must to get the Acid where I wanted it at .60. As I said before, I go slow, and add in stages so I don't over do it.
Hope this helps.
Treetoad - If you're serious about your winemaking you cannot test for acid using color change as the end point. You need a pH meter that reads to 0.01 pH units. It should have a replacable electrode that can be placed in the test sample. Titrate to pH 8.2 as an end point. Also, buy a burette that's calibrated in 0.1 ml increments to add sodium hydroxide solution. You can get excellent results that are very repeatable with such a system. I buy my sodium hydroxide and buffers from Presque Isle and have good, consistent acid testing results.
Bill Frazier Olathe, Kansas USA
DrinksForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.