Pinch of baking soda in boiling water (add sugar at this point if you use it and stir, while boiling, until melted)
steep in glass jar, pouring boiling water over tea (I use a huge Mason jar.)
remove tea bags after 10 minutes or so, do not squeeze them
let cool quite a bit on the kitchen counter, then
refrigerate, covered with lid.
I drink mine into the 3rd day without noticing an off flavor. But I also use sugar AND lemon.
Jan in VA