Stempel Polish Analysis Plugin doesn't work

Hello everybody,
Belowe example it has been invoked on es 2.3 and 1.7.
At first I installed plugin: https://www.elastic.co/guide/en/elasticsearch/plugins/current/analysis-stempel.html#analysis-stempel

Next my step was check correctly installed plugin:
Result on my screen:
Installed plugins in /home/adam/Desktop/elasticsearch-2.3.0/plugins:
- analysis-stempel
- marvel-agent
- license

Next I added mapping for blog:

curl -XPUT localhost:9200/my_index -d '{ 
 "mappings": {
    "blog": {
      "properties": {
        "title": { 
          "type": "string",
          "fields": {
            "polish": { 
              "type":     "string",
              "analyzer": "polish"
            }
          }
        }
      }
    }
  }
}
'

Then I added document:

curl -XPUT localhost:9200/my_index/blog/1 -d
'{ "title": "Bardzo kocham zółwie"}'

When I used:

curl -XGET localhost:9200/_search -d
'{
  "query": {
    "multi_match": {
      "type":     "most_fields", 
      "query":    "zółwie",
      "fields": [ "title", "title.polish" ]
    }
  }
}
'

elasticsearch returned correct result but if I put:

curl -XGET localhost:9200/_search -d
'{
  "query": {
    "multi_match": {
      "type":     "most_fields", 
      "query":    "zolwie",
      "fields": [ "title", "title.polish" ]
    }
  }
}'

elasticsearch nothing returns.

Problem is with polish special characters.