A/O formula needed

[rhoffart]

Well I completed my first 2 A/O tests. On the first sample it never moved off green indicating no free SO2's. Then I tested a store bought wine at it came in right at 160 ppm.

Then I was double checking the formula and I'm finding many different formula's out there.

Is there a place or book I can find the formula standard? Do you have one you would share?

I used the one pinned on winepress ... but I found about 5 different versions and they seem to all have a little different ingredients.

 

[BobF]

Did you purchase an A/O kit, or did you put one together yourself? Use the formula provided by the kit vendor or the formula that matches the wine sample size and strength of NaoH you're using.

Strength and volume of phosphoric acid isn't critical. Strength and volume of peroxide shouldn't matter as long as it's sufficient to bind with the SO2.

The final titration is the critical step and the strength of NaoH matters just like it does for a TA test - which is what you're essentially doing.

 

[ibglowin]

+1 to what Bob has said. I use 0.01N NaOH and a 20ml sample size. Formula is your ml of NaoH required to neutralize x 16 = PPM free SO2 under those conditions.

That 160ppm sounds like your off by a factor of 10 perhaps.

 

[rhoffart]

It’s home made … my concern was the quantity of the different chemicals used, but the more I read the more I understand.

My confusion is not knowing what the heck I’m doing … and reading somewhere to use 10ml of this and 20ml of that and 3 drops of the dye. And the clicking on another page and it says to use 10ml of this and 30ml of that and 5 drops of dye.

I believe I’m starting to understand … but until I get there I was looking for a guide of quantities and kinda step by step for dummies. I have found several they are all a little different.

 

[ibglowin]

I use the $99 one from morewine personally and love it. Here are the instructions with the kit in case you have not seen them.

A/O Instructions

What are you doing for Phosphoric Acid?

 

[rhoffart]

I use the $99 one from morewine personally and love it. Here are the instructions with the kit in case you have not seen them.

A/O Instructions

What are you doing for Phosphoric Acid?

Thanks

I bought it from morewine ... it's 25% as per most instructions