Acid test question

[Joanie]

I tested the Cayuga must twice for acid and I used 9 ccs. before I got the color change. Does that mean my acid is high or low?

 

[scotty]

I tested the Cayuga must twice for acid and I used 9 ccs. before I got the color change. Does that mean my acid is high or low?

note the amount of reagent used and multiply by .25 9ml X .25=2.25 it looks to be extra high.
9 ml Seems strange because the little graduated dropper only holds 3ml ((at least thats what mine holds))which i think are the same as a cc-- I have done only 2 acid tests so far and never had to use the full 3 ml


Im just looking at my crosby and baker acid test kit instructions and im as far from an experienced tester as you can get.
Its 4 am here and im just reading the instructions from my kit.


Wish i coud be if better help Joan

 

[masta]

I would assume you are using a standard acid test kit where take a 15 cc sample and add 3 drops of phenolphthalein, a pH indicator. Then add the sodium hydroxide slowly while stirring until you reach a color change in the sample. Each cc of solution represents 0.1% TA. So if you used9cc of solution before you saw a color change, the TA of your must equals 0.90%.
I am not real familiar with this varietal but the acid seems to be a bit high. How do you plan to finish the wine...dry or sweet?


Older sodium hydroxide that has been opened and exposed to the air could cause an improper reading.

 

[Joanie]

You assumed correctly, Masta!

Cayuga's are a hybrid grown in the north and my numbers are right with in line with juice records from the last 5 years.

 

[Angell Wine]

Your right Scotty 1ml = 1cc

 

[scotty]

Your right Scotty 1ml = 1cc

How old were you when you took the photo for your avatar

 

[OGrav]

Masta, this sounds like the kit I am using. Do you know if the NaOHsolution in it is supposed to be .1 or .2? The kit when I opened it had .1 in it, and when making a blueberry wine back in Mar, seemed to make sense. Ibegan to question myself when I made a strawberry wine months laterfrom scratch, started at .65 w/acid blendand addedthree cans of Welchesfrozen white grape concentrateto five gallons at first racking in secondary. Acid shot up to over 1.2%. Wasn't sure if active fermentation effected readings. Possible bad chemicals. Next trip to store bought replacement bottlefor LD carlson kit, and found this one at 1/5 normal or .2. To add more confusion, the bottle that orig came with the LDkit, .1 is Crosby/Baker, and the new one is LD Carlson, the 1/5. Almost every book I read has a different take on this, diluting/multiplying, etc.Is that much acid to be expected in the frozen concentrates? I've read some of the posts here andalmost seems like theyare adding more concentrate than sugar, I wonder what some of their readings were.
LT

 

[masta]

I am surprised to hear that the TA of your batch jumped from .65% to 1.2% after adding 3 cans of Welches concentrate and don't remember anyone talking about this issue before.

I believe there is an issue using different concentrations of Sodium Hydroxide. The best I can tell the acid test kits from LD Carlson come with a .2N or 1/5Sodium Hydroxidesolution and the Crosby and Baker come with a .1N or 1/10 Sodium Hydroxide solution.


A .1N solution is 4 grams of Sodium Hydroxide in 1 Liter of water.


A .2N solution is 8 grams of Sodium Hydroxide in 1 Liter of water.


What I don't know at the moment is if the instructions included in the Crosby & Baker kit use a different calculation than the LD Carlson kit (1cc/ml NaOH = .1% TA) to determine the TA.


Does anyone have a C&B acid test kit with a .1N Sodium Hydroxide solution than can check the instructions how to perform the test?

 

[OGrav]

That sounds like good news. If the LD Calson's kits actually come with LD Carlon 1/5 acid solution, (go figure),then my readings probably were off and my acid is not really as high as I thought. I wondered at the different brand on the bottle when I opened the kit but since I didn't know any better, didn't give it much thought. It wasn't until I went for a fresher bottle, that I realized there are different concentration available. Someone must have swapped it on the shelf. I just ameloriated an Ocean Spray grape/cranberry/blackberry juicemust witha couple cups of watertwo days ago. I pitched yeast last night, guess I can check again with the .2to see if I now need to add acid blend. Might be a reason for me to increase batch to 2 gallons.

Calculation wise, if 1ml of .2 solution=.1% acid, then 1ml of .1 solution should equal .05% acid, or use twice as much to neutralize, 14ml=.7%. Looked up LD Carlson's site, didn't see any accessible info on the kit.
LT