As I sit in the driveway, reading a book, listening to the migrating geese in the pond, and occasionally glancing at the brew kettle, I took a deep swig of my coffee. It was a great day for brewing, with the sun shining and only a bit of breeze. Even though most of my equipment is electric, I still enjoy taking a day to brew outside with my old homebrew set up. Even when you have all the brewing gadgets and “toys”, it’s just nice to take a step back and get back to brewing basics. For me, one of the best ways to scale back my brewing procedure is to do a brew in a bag session. Many brewers only do brew in a bag and it’s very easy to see why. Brew in a bag offers many distinct advantages including minimal equipment, less mess at the end of the brew day, and reasonably good brew house efficiency. The only two disadvantages with brew in a bag are temperature stability and mash control.
Below, I’ve outlined my Brew in a Bag Process. This is just one way which you can conduct a brew in a bag session and it far from the most efficient. I take a very low tech approach to brew in a bag which can be adapted to whatever equipment you have. If you don’t have any some of the tools Ive used, feel free to experiment (this can be your time to MacGyver some Homebrew)
Step 1 – Heating the Mash Water: As a general rule of thumb, put 1.5 quarts of water into your brew pot for every pound of grain your have (Example: For 10 pounds of Grain you would use 15 quarts of Water). Bring the water to approximately 160° F and remove the brew pot from the heat. If you want a more precise tool for estimating the amount of water you should use for the mash, go to Brew 365 and plug in your brew day numbers into the calculator.
Step 2 – Adding the Grains & Mashing: This is where you start to have a bit of choice. Personally, I add the bag to the water first (lining the brew kettle with the bag and allowing a pocket in the middle) and then add my grains while stirring. Alternatively, you can add your grains to the bag and then add the bag to the water. I prefer the former method because it allows you to stir the mash and get a homogeneous mixture, where as adding everything at once can give you the dreaded dough balls and decrease your efficiency. In either case add the grain bag and grains to the mash water and stir. Then put the lid on the pot and store it somewhere warm. If you are very concerned about loosing heat during your mash you can wrap your brew kettle in blankets. Let the mash rest for approximately an hour while you heat up your sparge water to approximately 170° F.
Step 3 – Lautering: Once again, you have some choice in how you want to lauter. I take the edges of the brew bag and form a very loose knot in the bag, so no grains can slip out. I then take a colander (or on this day a pizza cooling rack) and place the brew bag on top, over the brew kettle. At this point I use a measuring cup to slowly poor the sparge water over top of the grain bag, making sure to hit all areas of the bag. I continue this until I have reached my desired pre-boil gravity (again calculated through Brew 365). I have heard of other people putting their grain bag directly into the sparge water and simply mixing, but I think that this creates more mess and possibly less efficiency. Additionally, Ive heard of people adding all of their water at once and not doing any sparge. I would not recommend this last method since it could dilute the mash so much that the enzymes could not effectively reach the sugars, but the choice is yours.
Step 4 – Boil: At this point you will be conducting the boil as you would normally for any all grain brew day. Once the wort is collected, you can add heat and begin your boil. Once a boil is achieved, add hops as directed by your recipe.
Step 5 – Chill: Once the wort is finished its boil you begin your cooling process. Your goal it to get the wort down to approximately 70 degrees. Once it is cool, you will rack (transfer) your wort into your fermenter. The only special consideration you may need to make is how carefully you siphon off the wort. Brew in a bag can create more trub than when using a mash tun (partly due to the lack of a vorlauf step) and so more care is needed to avoid this greater amount of debris.
The remaining fermentation is exactly the same as with any other wort production method. Once again, my process of brew in a bag is certainly not the only way, but hopefully I have given you some tips on brewing with this awesome method.