Apologies for taking so long to get back to you on this. It's actually quite easy...
Exit Awasu and open up your user's <tt>CONFIG.INI</tt> file
in Notepad, find the lines that start with <tt>FeedItemDescriptionExcerptMinWords=</tt> and <tt>FeedItemDescriptionExcerptMaxWords=</tt> and adjust them accordingly.
Changing this will affect channel summary pages, channel reports and search result pages (if they are configured to show excerpted item descriptions, of course).