Originally Posted by marcelo
I used s-23. bothers me is also the fact of having first used a hop bag, and he was made of a very thin voile, this could have reduced the IBU and making the beer becomes acidic?
No, that can't happen. If you reduce the IBUs, the beer will taste sweeter, but there are not other flavor impacts.
It really sounds like stressed yeast combined with a too-high fermentation temperature.
It sounds like you've got esters (the fruity flavors), fusels (the hot alcohol flavor and smell) and possibly some phenols (the "clove" medicinal smell). I've never used S-23 so I don't have any experience with the temperature tolerance of it or the pitching rate.
One thing I'm considering, since you say you cooled the wort for two days and then added the yeast at the appropriate temperature, 12C, and then fermented at 12C- it could be from in infection while the wort sat and waited for the yeast.