Blue Wine Help

[ethalfrida]

I am brewing a tea wine using Butterfly Pea. It is blue and I want it to stay blue.
A group member told me to buffer with calcium carbonate so I won't have to use lemon. If I use lemon the color turns to purple.
So can anyone tell me how and when to use the calcium carbonate?
I am new to wine making. And, don't use any chemicals in my brews.
I appreciate any help I can get.

 

[jgmillr1]

I would guess that the pH of your tea wine is somewhere near the range of 7-8. What you are seeing with the color change is typical for the anthocyanin pigments often found in fruits and vegetables. Many wines will have a purple color that will change to blue as they are titrated with a base. Makes sense that this chemical process is reversible and you see that effect when you add lemon juice to the tea which lowers the pH.

Anyway to get back to your question... what is it you are trying to do with the calcium carbonate? That will only make the pH higher. I would go further and express concern that your wine will oxidize and spoil very quickly with such a high pH. Sulfites are essentially ineffective when the pH is above 4.0. Is there a recipe you are following from somewhere or are you experimenting?