It looks like it needed to be indexed in a special way, you might want to try customizing the indexing for that property by implementing a custom org.hibernate.search.bridge.FieldBridge.

I'd suggest to clone the source repository, import the project in your IDE and see the many included implementations of FieldBridge to have some examples.

Also, FYI if you checkout master right now it's already updated to latest Lucene 4.10.1