Partial Mash Brewing Technique
Brewing Partial Mashes
I had been brewing extract beers with specialty grains for a number of batches and really enjoyed this advancement in my home brewing. However, I was ready to take my brew again again a notch. I knew I could not yet afford to go all grain, but I wanted to experience all grain some way. What I discovered was brewing with partial mash kits.
Moving up to partial mash kits did require a few more pieces of equipment, most of which were easily found in my kitchen. Here is a list of the additional equipment.
- Second large pot with a capacity of about two gallons. This will supply the sparge water.
- A large fine mesh colander. This will be used to separate the grain from the wort before boil.
Start heating water in your brew pot. The quantity of water will be determined by the weight of grain included in your kit. For each pound of grain you need one quart of water. So if your kit has 3 1/2 pounds of grain, you need to start heating 3 1/2 quarts of water. This is known as your strike water.
Bring the temperature of your strike water to 10 degrees warmer than the desired mash temperature. If you want your mash temperature to be 151 degrees F, then your strike water needs to be 161 degrees F to proceed. The kit will tell you what your mash temperature needs to be for that particular beer recipe.
Add all of your grains to the water and stir them in well. If you have any clumps, they will need attention to break them up. Once the mash is created, measure the temperature and compare to the desired mash temperature. You can add either cooler water or hot water to achieve the desired temperature.
This temperature needs to be carefully maintained for the specified time found in your kit's instructions. Very often the time is around an hour. Gently adding heat to your pot to maintain the temperature will be needed. Be sure to stir when adding heat. I found if I had an electric burner on low I could add the pot to the burner just long enough to bring the temperatures back to the proper mash requirements and then take the pot off of the burner. I also found if I wrapped the pot with towels, it helped maintain the heat better. Be sure and remove any towels when adding the pot to the burner!
When the mash has about ten minutes left, start getting your sparge water ready. In the second pot, add the same quantity of water as your strike water and start heating. You will want this water to be brought to a temperature of 170 degrees F.
When you reach the end of your mash time, start raising the temperature of the mash until it reaches 170 degrees F. Constantly stir your mash so it does not burn. Once you have the mash at mash out temperature carefully pour it through the colander and collect the wort. I used my bottling bucket to collect the wort and was able to easily secure the colander to the bucket.
After you have separated the wort from the grain, you will sparge the grain by slowly pouring the 170 degree F sparge water through the grain in the colander. This step helps get the last bit of converted sugars out of the spent grain. You can now dispose of the spent grain. I like to use the spent grain as a compost product; however, the birds discovered the grains and had a smorgasbord feast.
The reminder of the process is just like you have always done with your extract brews .. Bring the water to a boil. Remove the pot from the heat source and add the liquid malt extract, mixing very well. Place back on heat source and bring to a nice rolling boil. Watch out for the hot break, which is the foaming up of the wort. This can result in the wailing boiling over. It is easily controlled with a spray bottle of cold water. Simply spray the foam to control it!
Once a good controlled rolling boil is reached add the hops. I always recommend using a hop bag.
The wort is boiled for an hour and then quickly cooled to yeast pitching temperature. Transfer the wort to your fermenter, aerate and add the yeast.
Place the fermenter in a dark cool location where the temperature can be maintained around 65 degrees.
This partial mash technique will give you a good idea of what is involved in all grain brewing and help you make the jump to all grain.