system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does cold brew tea have half the caffeine than hot tea, but cold brew coffee has more caffeine than hot coffee?
gpt
Almost certainly it's the brew time. the solubility of caffeine is not great at low temperatures (thus takes longer to extract), so the tea was probably not brewed for very long.

another thing to consider for coffee is that hot water likely doesn't contact the coffee for very long, where tea often is seeped for longer.