I know most of us use tea as a source of tannin when making juice wines but I was watching a video about medieval ink making (don't ask) and they mainly used oak galls / oak apples because of their high tannin content.
A bit of googling and indeed they are used to make commercial wine tannin. I must give this a try.
A bit of googling and indeed they are used to make commercial wine tannin. I must give this a try.
