Testing Acid in Reds

[K&GB]

I'm new to home winemaking, but I'm off to an ambitious start. I've fermented a Sauvignon Blanc and a Cabernet Sauvignon, which are currently clarifying, and now I'm fermenting a Viogner and a Sangiovese. I took initial readings of all four musts, but I wasn't able to accurately determine the acid content of either red wine because of their dark color. I doubled the volume in the test tube by adding water to dilute the color. Then I doubled the result, but in both reds the acid reading seemed impossibly high. The problem is that I can't really tell when there's a color change because the wine is already dark colored. Any advice would be appreciated?.

 

[JWMINNESOTA]

Testing for acid in the reds, and seeing the color change is a common problem. The best way to determine it is to verify with a pH reading, it will be 8.2 at the change.

 

[grapeman]

In order to check it for the 8.2 accurately use a digital pH meter. You can get inexpensive handheld sticks that work well enough for the home winemaker. Once the reading gets above 7, drip very slowly the sodium hydroxide because the last bit before change takes place very rapidly. Once you reach 8.2, you read how much of the NAOH you have added.

 

[K&GB]

I;m currently using a wine-acid test kit, but it looks like I'll be purchasing a PH meter.

 

[scotty]

I believe you are able to use water to double or even tripple the volume in a red wine test without having to double or tripple the result of the test.

Edited by: scotty

 

[Wade E]

Distilles water and I believe you an only dble it.

 

[scotty]

Distilles water and I believe you an only dble it.

i just threw my scanner out so ill do it the hard way.


crosby baker wine acid test kit.
condensed instructions
1-- fill test tube with 3 cc of must
2-- for dark or red wines add 2 syringes (6CC) of water preferably distilled
3---add 3 or 4 drops of phen-------etc
4 fill syringe with 3cc of indicator solution






etc etc
did i read it wrong??????

 

[smurfe]

You might look at the Accuvin test kits George sells. They are very nice, easy to use and read. Give him a call to explain which might work best for you. I used the sulfite's and pH tests and they were pretty well fool proof

 

[Wade E]

Scotty, you are correct as I was reading your post wrong thinking that you were adding 3 to 1 ratio. Using distilled water is a better idea especially if you are on well water.

 

[PeterZ]

K&GB,

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.

 

[Wade E]

Great info Peter and I think next year I will shoot for a digital PH meter as Ive run in to too many problems with testing reds, especially my blueberry. with a P.H meter, just add base until you reach 8.2 and your done for reds and whites, or so it says in "The Winemaker's Answer Book".

 

[K&GB]

Thanks so much for that explanation. This will really help when testing my reds.


Ken

 

[In 2 Wine]

Hi Wade, when you say "Just add base until you reach 8.2" What is base?

 

[grapeman]

Wade is referring to Sodium Hydroxide- NaOH. It is included with all the test kits. Just make sure it is fresh within 6 month old.

 

[In 2 Wine]

Ahh, Thank you Appleman