Acid test kit

[mainecr]

I can't seem to get my acit test kit to work.
I add must, 4 drops of reactive agent, and then add 1cc of change chemical at a time...until the test tube is full. Narry a color change.
Help! What an I doing wrong?

 

[Wade E]

If you doing this with a dark wine it is very hard to see a color change. Can we see the recipe you used as maybe the acid is way too high already to read without a bigger vial.

 

[Tom]

I'm betting its a dark red.

 

[Wade E]

Ive heard there is a way to dilute the wine to a certain extent to do this and will look into this for you.

 

[Tom]

dilute the wine 50% and multiple the result by 2

 

[Wade E]

Okay, I had to do some deep searching searching in another forum that I moderate which has a very scientific guy on there who deals with stuff like this as he works in the water treatment plant dealing with this syuff and here is what he wrote which I really neeed to know again.
"When you dilute a red wine with distilled (always use distilled) water you are adding neither hydrogen ions (acidity) nor alkalinity, which neutrailzes acidity. Tap water contains varying degrees of alkalinity, so you don't want to use that as it will give you an atrificially low reading.

The titration test is like counting the hydrogen ions in the sample. Thus, since distilled water adds no hydrogen ions, you can add as much distilled water as you need to and it won't change the test result. You don't even need to measure the distilled water, as it has no effect on the results. No matter how much distilled water you add, no correction factor is needed when calculating acidity from the results of your test.

So pretend you never added water to the samples and re-calculate your results. That will be the real acidity.

 

[mmadmikes1]

Damn , thats nice to know. I have been making it way to complicated

 

[Luc]

You can use the dilluting method I described here:

http://wijnmaker.blogspot.com/2008/11/zuurmeting-02-measuring-acidity-02.html

Great info Wade !!!!

Luc

 

[mainecr]

WOW.....
Lot's of dialogue...

Here's the recipe...from Jack Keller

· 6 lb blackberries
· 2-1/2 lb granulated sugar (I adjusted to 1.085)
· 1/2 tsp pectic enzyme
· 7 pts water
· wine yeast and nutrient
I used lalvin 71B 1112 yeast and a tsp nutrient per gallon

No color change....

 

[Luc]

Ok try this,

Take a cup of water and dissolve a bit of acid in it.
Acidity should be very low.
Best would be to take a liter water and dissolve about 3 gram tartaric acid in it. You would be certain that acidity would be 3 !!

Now test with that.
This should certainly give a colour change.

Luc

 

[Wade E]

Distilled water is the best to use as itwill not change your wine as all of the minerals have been removed.

 

[mainecr]

I added distilled water...worked great on tonights blueberry. Acid was about
.35
Thanks for the advise...bob

 

[Wade E]

Cool, glad to be of help.

 

[lovethepirk]

I am going to be making a blueberry wine next from scratch and need to test the acid. Will I be diluting and multiplying or not. I read through Luc's excellent descriptions on testing but Wade mentioned that multiplying is not necessary. I am confused.

Thanks.

 

[Wade E]

I retrieved my info from a water specialist who has many degrees in this area and runs the water plant in Memphis. He is a moderator on another wine forum and whenever anyone has anything super scientific he is usually the only one who can truly answer the question.

 

[lovethepirk]

So I can test this myself I assume. Just dilute the Must as needed and test it. Then dilute another same even more and test it. Should get same result.

--i take it 'blue indicator' is sodium hydroxide - NaOH

 

[lovethepirk]

In this article:
http://www.grapestompers.com/articles/measure_acidity.htm

This guy mentions using "phenolphthalein" as an indicator. Is this a different system than the method used in Luc's article? I don't remember him ever using anything but the must and the blue indicator.

Also what do you think about the acidity recommendations giving in the above article?

 

[Wade E]

The acidity recommendations are the same as Ive always gone by. I dont have the time to go back over Lucs method of testing but this is the way Ive always used my TA kit. If you are trying to test a dark wine it is very hard to test both of the results unless you are diluting both samples cause a dark wine is very hard to see a color change.