1 L water (may be less for denser concentrate - used this much for simpler measuring)
10 Lipton Green Tea bags - cut the strings, boil in that water for 5 minutes
7 ml citric acid crystals (? g)
8 ml potassium citrate crystals (Ostrovit, 4.8 g)
2 ml vitamin C powder (Adox group, 1.2 g)
4 ml caffeine powder (Adox group, 1.2 g)
40 mg potassium sorbate (Browin, not strictly necessary if consumed early)
250g erythritol
75g xylitol
Makes 4 L of resulting drink, mix 1:3.
Saturate with ~4 bar of CO2 after the mix has been cooled down to 4 C.
Does not foam, concentrate should keep rather well due to antibacterial and antifungal contents.
High caffeine content warning.
Yes, this is not mate, but it's chaicola modeled on Club-Mate Ice-T. Will be further improved and contain actual yerba mate once I get it.