The next step in home beer brewing is learning how to use a partial mash. This tutorial assumes you have an understanding of the Malt Extract Version of brewing. A partial mash is a slight modification of the straight extract brewing system from my previous article. It involves substituting some of the malt extract you would have used in a batch with a given quantity of grain. Mashing grain simply means mixing a given quantity of water with a given quantity of grain and allowing the mixture to steep for approximately an hour. The liquid is then strained from the grain and the grain is discarded. You are essentially making your own malt extract. Some people will even add a small grain rinsing, or sparging technique to partial mashing in order to extract more sugars from the grain. This, however, requires some extra equipment and we will not focus on this technique for now. Brewing using a standard partial mash adds approximately an hour to your standard brewing schedule. However, the benefits of performing a partial mash are many. You can have more control over the flavor of your beer and mashing some of the grain yourself gives a fresher flavor. Some lighter beer styles require that you at least do a partial mash because the lighter color that is required by the style is unobtainable due to the carmelization that occurs during the malt extract production process. Interestingly, Beamish uses a partial mash coupled with the use of malt extract during the production of their stout. The partial mash brewing process is no more difficult than the previous method and there are only a couple more items necessary to brew in this manner. I have chosen a different recipe for this tutorial and the ingredients are listed below. You can, of course, substitute a different partial mash recipe if you choose.
Beer Brewing Equipment
- Stock pot of at least 4 gallons in size (16 quarts)
- Long spoon to stir the brew
- Fermenter (a 6 1/2 gallon food grade plastic bucket or glass carboy)
- Airlock (available at your local home brew store)
- A sanitizing agent (chlorine bleach, iodophor is better)
- Optional bottle filler
- 1 brewing thermometer
- A brewing hydrometer
- 54 cleaned and sanitized bottles (non twist-off type)
- Bottle caps
- A bottle capper
- Optional secondary fermenter (a 5 gallon food grade vessel)
- A 5 gallon food grade bucket for bottling
- A brewer’s racking cane with hose (for siphoning beer)
- A large pot of at least seven quarts in size that you can put in the oven.
- A large colander
Ingredients For A Flaked Barley Stout
- 6 lbs Amber Liquid Malt Extract
- 1.5 lbs Crushed British Pale Malt
- 1 lb Crushed Flaked Barley
- .5 lb Crushed Caramel/Crystal Malt — 120L
- .5 lb Crushed Chocolate Malt
- .5 lb Crushed Roasted Barley
- 2 oz Kent Goldings Hops
- 1 oz Fuggle Hops
- 1 vial of pitchable White Labs Irish Ale Yeast
- 1 teaspoon Irish Moss
- 3/4 cup corn sugar
- The brewing day begins by making sure that all of your “tools” have been thoroughly cleaned and sanitized. This means that every piece that will come in contact with your brew has been thoroughly cleaned and has been soaked in a solution of one tablespoon chlorine bleach to 1 gallon of water for at least an hour. After everything has been cleaned, sanitized, and rinsed well, it is time to begin the brewing procedure.
- Make sure you allow the yeast you are using to warm to room temperature for at least 6 hours before you begin your brew.
- Bring 1.2 quarts of water per pound of grain to 150 degrees on your stove in your large pot or Dutch oven. For this particular recipe, this amounts to 4.8 quarts. While you are waiting for the water to get to the appropriate temperature, turn your oven on and set it to its lowest setting.
- Place your crushed grains into the water and thoroughly mix them. Put the top on the Dutch oven or large pot and place the vessel in your oven. Leave it in the oven for exactly one hour. During this time, enzymes are activated in the grains and the fermentable sugars are extracted.
- After the hour mashing process is complete, remove the pot from the oven. Place the colander over your brewing pot, and slowly dump the mash into it. Allow the liquid to enter your brew pot and discard the spent grain.
- Add enough water to the brew pot to bring the volume of liquid up to 2 gallons. Bring the solution to a boil. Once it has reached a boil, turn off the heat and dump your Amber Malt Extract into the water. Use the hot water to soften the extract left in the container and dump the remains into the boil kettle. Make sure to stir the liquid (now known as wort) to avoid having your malt extract scorch.
- Place one of the one ounce Kent Goldings Hops packets and the one ounce Fuggle Hops packet into the kettle and begin boiling your wort. Make sure you pay attention, it is possible to have a sticky boil over when the boil begins. This wort boiling procedure will take exactly 60 minutes. During this time, the bitterness, flavors, and aroma of the hops will be extracted and the wort will be sanitized.
- 45 minutes into the boil, place one teaspoon of Irish Moss into the boil. This will aid in the coagulation of proteins and will result in a cleaner tasting final product.
- 50 minutes into the boil, place the remaining one ounce packet of Kent Goldings Hops into the boil. This is the Hops addition that will add a nice aroma to your beer.
- After the 60 minute boil process has completed, it is time to cool the wort to yeast pitching temperature. This means putting the boil kettle into your sink filled with ice and water. Frequently stirring the ice around the boil kettle will assist the cooling procedure. Also stir the boiled “beer” with a sanitized spoon in order to speed the process.
- Once the liquid has cooled to approximately 80 degrees, it is time to transfer it to your sanitized fermentation bucket or carboy. Use sanitized water to bring the final liquid volume up to 5 gallons. It is at this time that you might want to use your brewer’s hydrometer to measure the specific gravity of your beer (including the added liquid). Fill the hydrometer’s tube with the beer and allow the hydrometer to float in a container. Read the number that appears at the liquid line. It should be a number that looks something like 1.052. This number can allow us to determine the final alcohol content of our brew.
- Pitch your yeast into the beer and vigorously shake your fermentation tank. This agitation will help to increase the amount of oxygen in the beer. At this point, the yeast need a lot of oxygen in order to begin a healthy fermentation. Seal your fermentation vessel with the water-filled sanitized airlock.
- For most beers, fermentation will begin within 36 hours. Depending upon the style of beer you are making, the fermentation process will last anywhere between 4 to 7 days. If you have a secondary fermentation tank, it is at this time that you would siphon your beer off the yeast sediment in the primary fermenter and transfer it to the secondary. Fermenting beer that is treated in this manner and left in the secondary fermentation tank for at least 2 weeks will become much clearer and have a cleaner flavor. This process, however, is completely optional.
- Once fermentation is complete, transfer the beer to a bottling bucket. Add 3/4 cup of corn sugar that has been boiled with a cup of water. Stir the beer well to make sure the sugar solution is evenly mixed into the solution. Be very careful not to splash the beer at this point. Splashing can cause oxidation in the beer which can lead to off-flavors.
- The beer may now be transferred to the cleaned and sanitized bottles. It is also at this time that you should use your hydrometer to measure the final gravity of your beer. Place bottle caps on the bottles and allow them to sit in a warm place for approximately 14 days. You can enter your original and final gravities into the Beer Statistics calculator on my Calculator and Texts page in order to find out the alcohol content, calories per 12 ounces, and carbohydrate content of your beer.
- Enjoy your home brewed beer. Home brewed beer is best enjoyed in a clean glass. Pour all but the last quarter inch of beer from the bottle into the glass. This will leave behind the spent yeast cells that have finished performing their duties.