Brewing with extract is fun a simple. You can make some amazing beer using extract but it does impose limitations. The hobby of homebrewing becomes all the more exciting and dynamic when you’re brewing with all-grain. All-grain brewing offers more control over fine-tuning recipes and brewing increasingly complex styles of beer. So what’s holding you back?
The cost associated with building or buying a mash tun can put people off. It’s true that, If you want to brew 23L (6 gallons) of all-grain beer, there can be a substantial initial investment of either time or money (although it’s surely worth it in the long run!). BUT there is another way! If you’re already brewing extract you can make the leap to all-grain by simply buying a nylon strainer bag ($3.50!). All you need to do is downsize to a half-size batch of 11.35L (3 gallons). As a bonus, these smaller batches allow you to experiment more with different styles and different ingredients. The method you’ll use is called “Brew In A Bag” or “B.I.A.B.”
You’ll need a 19L pot (if you don’t already have one, pick one up for $29 at Barley’s) another large pot (10 to 15L) and a nylon strainer bag. depending on your recipe you’ll have about 2kg to 3.5kg of milled grain which you will need to mash. This is different than steeping in two ways: temperature and time. When you steep grains, it’s in “hot” water for about 30 minutes. Mashing, at it’s most basic, includes hitting a precise temperature and holding it there for 60 minutes. The temperature depends on your recipe but it’s typically within a few degrees of 65C. Traditionally, mashing is done in a mash tun, which would be a separate vessel than your brew pot. When you’re doing BIAB, your brew pot IS your mash tun and everything can be done right on the stove top.
Fill your brew pot with water leaving enough room for the grain. An easy way to do this is to put your grain in a plastic bag and place that in your brew pot while filling it with tap water. Remove the bag of grain and, voila, you now have the correct amount of water in your pot. OR if you prefer, the ratio of water to grain is about 3L/kg. Bring the water up to “strike temperature”. This is about 10 degrees hotter than your mash temperature. Turn off the heat and place your nylon strainer bag into the pot. Add your grain into the nylon bag, stirring it into the water gently. By the time all your grain is added, the temperature should stabilize. If it’s too hot, stir gently or add cool water to bring the temperature down. If it’s too cold, turn the heat on low and stir the mash as the temperature rises. Be sure to take temperature reading from different areas of the mash. The sides and bottom will be a bit hotter than the middle. Leave the lid on but stir the mash every 10 minutes over the course of an hour. The grain insulates itself pretty well but it may be necessary to add some heat (on low) once in a while.
During the mash, you’ll want to heat up more water in a separate pot to use for sparging. heat this water up to about 80C. You’ll need enough sparge water to fill your brew pot after the grains have been removed. You’ll want a pre-boil volume of about 16L (Not too much. You don’t want a boil-over). You’ll lose about 4L to evaporation over the course of a 1 hour boil and end up with about 12L of wort to add to your primary.
Sparging is the process of rinsing sugars out of the grain after the mash. When the mash is finished, you’ll pull the nylon bag out of the pot and allow the water to drain out. This is the equivalent of the traditional Lautering process, which is just removing the wort from the mash. You can sparge by showering the hot water over your grain bag, allowing the runnings to drain into the brew pot, OR you can dunk the entire grain bag into your pot of sparge water. Stir gently and let sit for 2 minutes. Pull out the grain bag and add the sparge water to your brew pot.
From that point on the process is the same as extract brewing but now you’ll have a full volume of wort in your brew pot and it will not be necessary to top your fermenter up with tap water.