This should help some..from Jack Keller:
Starch Haze: Starch hazes form when starchy materials used to make wine are misused, usually by boiling them too long or squeezing their pulp too severely to extract additional flavor. Starch haze is tested by adding 5 drops of iodine to 8 ounces of wine. If starch haze is present the wine will turn indigo blue. Treat with Amylase or Amylozyme 100. Amylase is used just like pectic enzyme is used to treat pectin haze. For each gallon of wine draw off one cup of wine and stir into it teaspoon of Amylase. Set the treated sample in a warm place (70-80° F.) and stir hourly for four hours. Strain the sample through sterilized muslin cloth and add to the bulk of the wine. Leave the wine at 70° F. for 4-5 days. The haze should clear. If it does not, strain the wine through sterilized muslin cloth and then through a vacuum-pumped filter. Amylozyme 100 is used differently. Treat with 1/2 ounce Amylozyme 100 (one tablespoon) per gallon of wine and bring into a warm room (70-75° F.) for a week. The wine should clear.
Parsnips, potatoes, turnips, grains, apples, pears, or any starchy material can produce a haze. A number of recipes warn the reader to put the material in a nylon straining bag and later to drip drain the ingredient or very lightly press it. These instructions almost always accompany ingredients which produce starch hazes and the reader will have no problem if the directions are followed.
Any one know what causes this and what I can do to prevent it? I know I read about it somewhere but can't recall the source any more. (Actually Bert's question but he's got a Polish Wine Princess to handle his secretarial duties.)
