Hi!
I've created a new plugin for ES. Now your ES can support Morfologik
(http://morfologik.blogspot.com/) it's a very good polish stemmer in
alternative to Stempel Plugin.
You can you is as analyzer or token filter. Check it
out: https://github.com/chytreg/elasticsearch-analysis-morfologik
I did also a pull request
(https://github.com/elasticsearch/elasticsearch-analysis-stempel/pull/3) to
Stempel plugin to support using Stempel as a token filter.