Clear Beer or Cloudy Beer
Part of the character and charm of a Hefe-Weizen or Belgian Wit beer is the cloudy appearance. In most other beer styles, the presentation should be clear. Yeast and/or proteins in suspension can cause a beer to be cloudy before and after it is chilled. If it becomes cloudy only when chilled, the beer is said to have a chill haze. A chill haze is caused by the combining of proteins and tannins which come out of suspensions and occurs only when the beer is chilled.
The first step to making clear is the used of Irish Moss or Whirlfloc Tablets which are an Irish Moss derivative. Irish Moss is added the last 20 minutes of the kettle boil facilitate the 'hot break' which aids the proteins in coagulation and precipitation. This looks a bit like egg drop soup in you kettle. Then getting a good 'cold break' when chilling the wort following the boil also breaks proteins out of suspension. Allow the proteins you broken out of suspension to settle to the bottom the the boiling kettle for about 30 minutes before transferring to your fermenter. When transferring, leave the proteins you've worked so hard to break out of suspension behind in the kettle along with the spent hops.
After fermentation is complete, there will be a lot of yeast still in suspension in your beer. Gelatin Finings are added 5-8 days prior to bottling. Gelatin is a positively charged protein which reduces polyphenolic compounds (astringent or bitter husk and hop tannins) by attracting these negatively charged compounds along with yeast. Since they work like a magnet, when they become heavy enough the gelatin along with all the compounds they have attracted will fall to the bottom of the fermenter. Rack off this sediment to a clean vessel prior to adding priming sugar and bottling. The result will be a clearer beer, less sediment in the bottle and what is there will be more compact and easier to decant off of.