Brew -in-a-bag (BIAB) is a full-volume, all-grain brewing process using a single kettle. The appeal of BIAB brewing to me is the great quality beer that you can make using a very simple process. In fact, if you stick with the basics, you could start brewing BIAB without ever brewing extract.
So here’s a down and dirty primer to get you started. Below are the items that may be different than what you are using for extract brewing.
Large Brew Kettle
This is a 17,000 BTU burner on our kitchen cooktop. I can get a decent boil out of it if I don’t feel like brewing outside.
With extract brewing, a 5-gallon kettle works well. You could brew just as easily on a stovetop as you could a propane burner. It’s easy enough to handle, so a ball valve isn’t necessary. With BIAB, you need a 10-gallon kettle at a minimum. Don’t bother trying to get one of those 7-gallon turkey fryer kits. It’s just not going to be large enough. Also, plan on installing a ball valve on your BIAB kettle. It’s going to be pretty heavy when full, so with a ball valve you can transfer your wort easily and safely.
Unless you have a high BTU burner on your stovetop, you’ll most likely be brewing outside on a propane burner. If you have an electric stove, you may want to see if you can get a canning burner element for it.
Large Grain Bag
Well this is the “bag” in brew-in-a-bag! You have a couple of options here. One is to simply buy a course-mesh nylon grain bag from your local homebrew supply and the other is to get grain bag specifically made for BIAB. Bags from your homebrew supply are typically 24″ x 24″ or 24″ x 36″ in size. The premium custom bags can be closely tailored to your kettle’s size and dimensions. They are also typically made of polyester and have reinforced seams with sewn-in handles.
Which do you choose? Start with the less expensive version from your homebrew supply. It’s cheap and reusable for a few brew sessions. As you dial-in your equipment and process, you may consider upgrading, depending on your needs. Since my kettle has a basket strainer, the basic bags work just fine for me.
So you can follow the all-grain recipe easily, just ask you homebrew supply to double-crush your grains. It will aid in the extraction process and allow you to order the same amount of grains that the recipe calls for. You could also add more grains to the grain bill in lieu of double crushing, but we want to keep things as simple as possible here, as we get started.
BIAB Water Calculator
This is another area of BIAB brewing that can get more complicated if you want it to. Basically, BIAB is a full-volume process, which means that you need to calculate how much water you need to start with and that will take you through the entire brew process. I’ve covered this more completely in this HBT article: Water Requirements For BIAB Brewing.
The BIAB Process Steps in a Nutshell
Here’s a quick rundown of what you’re going to do:
- Use the calculator to calculate your strike water quantity
- Bring that amount of water to the strike temperature you calculated. This number will be higher than the typical mash temperature of 152F to compensate for the cooler temperature of the grains before they are added.
- Mash your grains for 90 minutes, stirring occasionally. Your brew sheet will probably say 60 minutes, but always mash for 90 minutes to increase your efficiency.
- After the 90 minute mash is complete, raise the temperature to 170F. Stir the mash and let sit for 10 more minutes. This is the mashout.
- With the mashout complete, you simply pull the bag out of the kettle and let it drain off, or gently squeeze it. Be careful during this step – it’s going to be hot.
- After you’ve drained off the bag you have your wort. Now the process is the same as extract brewing. Take your pre-boil gravity sample, record the pre-boil wort volume and temperature, then start your boil.
If you’re new to BIAB, you can see how easy it is to get started with brew-in-bag. Hopefully you’ll also notice the quality difference in your beer. If you take the time to calculate your equipment’s boil-off rate (see Water Requirements For BIAB Brewing), you’ll have a better chance of hitting your final numbers.
To see start-to-finish BIAB brew sessions videos, please check out BIAB Brewing on YouTube.