Flavor

• Unmalted oats generally do not contribute much to the flavor of beers. Due to its hard outer shell and the characteristics of its glucose molecules, the oats must be cooked prior to inclusion in the beer recipe. This cooking process breaks down the starches, effectually leaching out the flavors. By the time the oats are used in the beer, any oatmeal flavor has been broken down. This, combined with the relatively small amount of oats needed in a home brew recipe, results in the absence of a flavor contribution.
  
  

Texture

• Many grains are cooked to produce beer and are filtered out before the beer goes into fermentation, so there is no oatmeal texture to the beer itself if using unmalted oats. The texture of the finished beer however, is highly influenced by the high fat, oils and protein contents of the oats used earlier. Leaving the oats unmalted means that much of the original starches are utilized. The result is a very smooth beer, somewhat thick with the effect of the flavors having been bonded together by the oats.
  
  

Process Considerations

• If you decide to use unmalted oats in your recipe when you brew at home, there are a few things to take into consideration. The oats will enhance the viscosity of the beer and potentially cause problems during sparging. The density of the oats may inspire a stuck runoff, where sparging becomes impossible due to the impermeability of the grains. The more oats used, the slower the lautering must become to prevent a stuck runoff. The oats must be gelatinized before brewing with them by fully or partially mashing them - effectually cooking them to break down their most structured starches. Without these starches available, the oats are useless in the recipe.
  
  

Types of Oats

• Processed oats are easier to use when brewing beer at home, as they have already gone through a starch breakdown once. Flaked, or rolled oats are already gelatinized and do not have to be cooked by the brewer at all. These are the same oats you eat for breakfast and can be found at a grocery store. The oats labeled quick oats or one-minute oats are cut down into very fine pieces.Flaked oats can be found at a brew supply store and have the same pre-gelatinized features as the breakfast oats. The steel cut-labeled oats are the entire kernel and must be boiled and stirred constantly for between 45 minutes and two hours.