Partial Mash versus Steeping with Specialty Grains
Completing a partial mash and steeping with specialty grains are two very similar processes, so we thought we'd point out the small but crucial differences for our brewers. If you are more interested in the execution of one versus the other, be sure to visit our blog on just that, titled "Steeping and Mashing 101." A great starting point is understanding the all-grain beer brewing process of "mashing," which is the process they are standing in for. Mashing is soaking crushed grains (nearly always malted barley) in water. Put simply by BYO,
As the grains soak, the water dissolves the starch in the grains. Enzymes from the grain attack the starch and chop it up into its building blocks, sugars. Once the starch is fully converted, the sugars are rinsed from the spent grains.
This same process is mimicked with a partial mash. However, partial mashes use less grain, so soaking and rinsing the grain (sparging) is easier and doesn't require the special equipment standard mashing does. A partial mash only calls for a grain bag and measuring cup. When comparing mashing, partial mashing, and steeping with specialty grains – the key difference is where the fermentable sugars are coming from.
Fermentable Sugar Source
Mini biology lesson: Fermentation = Yeast convert Sugar into Alcohol (to Obtain Energy).
Therefore you, the brewer, need to complete a process or add an ingredient that will give the yeast those sugars. All-grain brewers extract those fermentable sugars through mashing. However, mashing requires strict attention to temperature, pH, and water chemistry. Because of this, those who are just starting out, those who do not wish to invest in lots of equipment, and those who want to save time all turn to simpler processes like partial mashing or steeping their grains. With both a partial mash and a steep, you will use malt extractto provide most of the fermentable sugar to the yeast. It is the use of malted grains in both processes that will further differentiate them. If you are brewing with extract and steeping specialty grains, nearly all the fermentable sugars come from extract. For a partial mash, you will do what is called a "mini-mash," (mashing like an all-grain brewer, but on a smaller scale) and then supplement those fermentable sugars with malt extract.
Grains for a Steep or a Mash
Steeping and mashing will both call for soaking the crushed grains in water, but with mashing you have a narrower range of temperatures and grain-to-water ratios (you don't want to soak the grains in too much water). So, of the three processes – mashing, partial mashing, and steeping – steeping with specialty grains is the simplest approach as there are fewer factors to control. With a partial mash, you use grains that will convert their starches into fermentable sugar (i.e. Munich, Maris Otter, Vienna, etc.) In a steep, you usually use pre-converted specialty grains, such as crystal malts, cara- malts, roasted malts, etc. With those grains, sugars have been caramelized (crystal and caramel malts) or charred (roasted malts) through a special heating process. The grains also play a role in why brewers will spend the extra time and focus to do a partial mash, even if a steep is simpler. A partial mash will allow you flexibility with your grains. You won't be limited to crystal, roasted, and other pre-converted grains. Still, various specialty grains in a steep will add color, flavor, and aroma beyond a standard extract brew. It should also be noted that a partial mash can allow for a lighter-colored beer, compared to extract brewing then steeping with specialty grains. Both methods boast their benefits, but hopefully the difference between the two is now clearer. If ever you want guidance or tips with either method, don't forget to reach out to our customer service pros (email@example.com or 1-800-852-4263).