If you have been brewing beer as an extract homebrewer looking to step-up to all-grain brewing, or if you are already an all-grain brewer who is looking for an easier brew day, learning how to brew in a bag, also known as the BIAB brewing method, is the way to go.
So no matter what you may have heard or read from other seasoned homebrewers, there is nothing wrong with brewing in a bag when being introduced to all-grain brewing. And yes, you can still use all of your favorite recipes, while still saving an hour or more of time on brew day.
When you brew in a bag, all of the mashing, boiling, and cooling is done in just one vessel, instead of the standard three vessel system with traditional all-grain beer brewing.
Table of Contents
What Is The Brewing In A Bag Method?
Brew in a bag is a simple and cost-effective way for any homebrewer to enhance their brewing skills without all the extra equipment.
With traditional all-grain beer recipes, you need a large kettle, mash tun with a false bottom, and a hot liquor tank, in addition to your regular extract brewing equipment.
But with the brew in a bag method, you don’t need the mash tun and a hot liquor tank. All you need is the same brewing kettle, a good heat source, a brew bag or a large nylon grain bag, and an optional false bottom to keep the bag off the bottom of the pot.
The crushed grains will be added to the brew bag inside of the kettle, and everything before fermentation will be completed from just the brew pot. Plus no sparging is necessary when BIAB.
Equipment Needed For Making a 5-Gallon Batch of Beer
The good news is if you have been brewing with extract and previously bought a home beer brewing kit, you will still be using most of the equipment you already have, and will probably just need a few more things on BIAB brew day.
It is a good idea to have a brewing kettle or pot that is double the size of the batch of beer you are brewing, and is large enough to hold the pre-boil volume of water. So if you are making 5 gallons of beer, you should get a 8 to10-gallon pot, which will hold the full volume of liquid.
With extract brewing, you can get away with a smaller brew pot because most brewing recipes call for a partial boil of 2 or 3 gallons.
Because of 5 gallon extract recipes call for a partial boil of 2-1/2 to 3 gallons of water, most kitchen stoves can bring the water to a boil without a problem.
But when boiling a 5 or 6 gallon full volume of water, an induction burner or propane burner will most likely be needed. If you want to use an induction burner, just make sure your brew pot is compatible.
As is with most products, you usually get what you pay for, and a brew bag is no different. A good quality brew bag can last for hundreds of brews if taken care of.
Brewing bags come in various sizes and made of different materials. When brewing in a bag, you will want to get one that has a fine mesh that will catch as much of the crushed grains as possible.
But keep in mind that your grain bill will also be limited to the bag size, so make sure you get one large enough to handle your grain batch.
Clamps To Secure The Bag
Many bags come with a draw string to keep the bag falling into the pot during mashing. Even if the grain bag you choose has a draw string, investing in some simple and inexpensive clips is a wise choice to keep the bag off the bottom of the kettle.
Draining Rack or Pulley System
You will need a way to lift the bag that is filled with water-logged grains out of the kettle. Maybe you have a cherry picker in your garage or a pulley system hanging from the ceiling, but a clean bbq grill grate (step #6 below) with do just as good of a job.
It might be a good idea to have a helper when it’s time to lift the bag.
Like any batch of beer, you need to get the wort down to yeast pitching temperature quickly as possible.
For partial boils, using an ice bath in the kitchen sink can do the trick, but for a full volume boil, an immersion, counter-flow, or plate wort chiller is highly recommended. A wort chiller can get the wort temperature down from 212° to yeast pitching temp within 15 to 20 minutes.
Many larger brew pots already have a thermometer installed, but sometimes they can be inaccurate. A instant read digital thermometer will quickly let you know what the mash temperature is.
Brewing Equipment You Probably Already Have
Moving to BIAB from extract brewing still uses most of the same equipment that you already have.
- Plastic bucket and/or glass carboy for primary and/or secondary fermentation
- Stirring spoon
- Cleaner and sanitizer
- Hydrometer to measure original gravity and final gravity
- Bottling bucket
- Transfer tubing
- Bottling wand
- Bottle capper and caps
- Glass bottles or kegging system
There are quite a few advantages of using the brew in a bag method instead of the traditional all-grain brewing method.
- Cost effective way to brew with all-grain
- Ideal for new homebrewers as well as advanced brewers
- Less equipment is needed (no mash tun or hot liquor tank)
- Requires less space
- Less equipment to clean and sanitize
- Losing some efficiency in the mash
- Mash temperature can be more difficult to control, especially when brewing in colder environments
The BIAB Process
The brew in a bag method is a simple way to brew with all-grain, but can be done with less equipment than traditional all-grain brewing. After a few beginning steps in the BIAB process, the following steps will be the same, as if brewing with extract.
Step 1: Decide On Which Beer You Will Be Brewing
Once you decide on which beer you would like to brew, it’s time to gather up all your ingredients. Your beer recipe will tell you the type of grains and hops will will need, along with the amount.
You can get your ingredients from your local homebrew shop, or you can order them online. BrewersFriend is a great resource for all your homebrewing recipes and calculations. You could also consider buying an all-grain ingredient kit that already has everything pre-packaged.
Step 2: Calculations For The Water Volume
You need to figure the amount of pre-boil volume of water you will need to begin with for the beer batch size you are brewing. You will also need to calculate how much water you will lose during the boil, due to grains adsorbing some of the water, along with losing some through evaporation.
This will ensure that you have the correct amount of liquid for fermentation after the boil is completed. Once you have the correct amount of strike water ready to go in the brew pot, begin heating the water to the desired mash temperature.
Keep in mind that you will lose a few degrees once the grains are added to the water, so you will be heating the water to a bit higher strike temperature.
But not to worry. You can find a number of online brewing calculators to help you get these strike water numbers.
If you are using plain tap water that is high in chlorine, now is the time to add Campden tablets to the strike water. When you use store bought bottled drinking water, adding the Campden tablets is not necessary.
Step 3: Measuring/Milling The Grains
When you buy your grains from your local homebrew shop, ask them to crush your grains very fine, or run them through the mill twice.
If you plan on milling your own grains, you should start doing this now while your strike water is heating up. Make sure you measure the grains by weight and not volume.
If you already own a grain mill, you can crush the grains to your desired grain crush. Like the homebrew shop, you might need to run the grains through the mill twice. For the BIAB method, you can crush your grains to the finest setting possible without any problems.
Step 4: Adding Grains To Kettle and Mashing
After the water has reached the calculated strike temperature, put your nylon brewing bag inside of the kettle and begin adding the grains. You can use a false bottom or clips to keep the bag off the bottom of the kettle.
Keep adding the grains a little at a time while continuing to stir with a long spoon until all the grains have been added. Make sure you mix well to avoid the dreaded and unwanted “dough balls”.
As we said earlier, it is normal for the water temp to drop a few degrees after adding the crushed grains. Once the mashing temperature has been reached, turn off the heat source, cover the pot, and set the
timer for 60 minutes.
You might need to wrap the kettle with blankets or some sort of insulation jacket to keep the temperature from dropping too much during the next 60 minutes.
Don’t worry too much if you don’t hit all your target numbers exactly, especially if it’s your first time brewing in a bag.
Step 5: Mash Out (Optional)
After the 60 minute mash, “mash out” is the process of raising the temperature of the the wort to approximately 170°F for about 10 minutes.
Increasing the temperature for the extra 10 minutes will extract more sugars from the grains. It also is intended to denature the enzymes, and “set” the final profile of the beer.
Although you can mash-out with BIAB, it is not necessary since the time between mashing and boiling is relatively short. But if you do, make sure your brew bag is not touching the bottom of the brewing kettle if you do.
Step 6 : Removing the Bag
After the mash, time to lift the bag from the pot. Depending on your specific grain bill, the bag will be heavy and could weigh as much as 20-pounds when the mash is complete.
Some homebrewers like to use a hoist that is attached to the ceiling, or a lift system made from a ladder and pulleys to help remove the bag from the brew kettle.
We find that the easiest and most simple way is to grab a partner, lift the brew bag from the kettle, and set the bag on top of a clean bbq grate, or some kind of wire rack over the top of the pot.
Let the bag drain for a few minutes and then begin squeezing the bag to extract as much as the sugary liquid as possible.
Some experts say that squeezing the bag can extract unwanted tannins from the grain husks and shouldn’t be done. Go ahead and squeeze the bag, it isn’t going to hurt anything.
Step 7: Sparging (Optional)
Sparging is a standard step in all-grain brewing, but it’s not required when you brew in a bag. Sparging is when you use hot water to rinse off the grains to extract as much of the fermentable sugars as possible.
If you really feel like you want to sparge, go ahead and do it by heating up some hot water to 170°, but it’s not needed for the BIAB method and can be skipped.
At this point, the rest of the process is the same as if you were brewing with extract.
Step 8: Boiling
After you have removed the grain bag, it’s time to crank up the heat and get the wort boiling. Most beer recipes are centered around a 60-minute boil, but that can vary.
Once the wort has begun to boil, it is usually time to add the beginning hop additions. Adding the hops at the beginning of the boil is what will give the wort bitterness, and balance out the sugars from the malt.
It is important to have a large enough pot to eliminate boil-overs which can be messy and dangerous. Propane burners with a high-powered BTU output can create a boil-over very quickly. Using an electric kettle can be a more gentle heating process and cut the risk of a boil-over.
During the 60-minute boil, and depending on your recipe, you might also be adding additional hops or other ingredients at specific times during the boil process.
Step 9: Adding Late Addition Hops and Fining Agents
Usually with about 10-minutes left in boil, additional hop additions might be added for flavoring and/or aroma. This is also the time where Irish Moss or Whirlfloc tablets can be added to the wort.
Adding these fining agents to wort will help to clear the beer. Also, if you plan on using a wort chiller, you can submerge the clean coils in the boiling wort to sterilize the wort chiller.
Step 10: Cooling the Wort
Before you can transfer the wort to the fermenter and add the yeast, the hot must be chilled to the correct yeast pitching temperature as
quickly as possible.
There are many ways this can be done:
Depending on the batch size, the fastest and safest way to rapidly cool the boiling wort is with a wort chiller.
An immersion chiller, counterflow chiller, or a plate chiller are the three types of wort coolers you can use, and each one of the three types of chillers has their own advantages and disadvantages.
If you are looking to purchase a wort chiller and need a little help deciding on which one would be best for you, check out our reviews of the best wort chillers for homebrewing.
*One popular way is to submerge the brew kettle in a ice bath while continually adding fresh water and new ice to the sink as it melts. This method can take up to 45-minutes or more before you can get the wort chilled to the right temperature.
Stirring the wort one direction with a clean and sanitized spoon, while rotating the kettle in the opposite direction can speed up the process. Just make sure you don’t splash any of the ice water into the wort.
* This method is best when cooling down partial boils, and not really recommended for full boils because of the amount of time it will take to get down to the right temperature.
And the last way is with the “no chill” method, and one we do not also recommend for large batches either. This is when you pour the hot wort into a clean and sterilized high density polyethylene (HDPE) cube or jug, and allow the wort to cool naturally over-night.
Just check and make sure the jug you are using is a food-grade plastic.
If you have a spigot on the brew pot, attach some clean and sanitized transfer tubing to the spigot, and drain the wort into the jug. After
you have transferred all the wort, make sure the lid is sealed tight.
Step 11: Transferring To The Fermenter and Pitching The Yeast
After you have cooled the wort to an acceptable temperature range for the yeast, transfer the wort to your cleaned and sanitized plastic fermenting bucket or glass carboy. Avoid transferring any stray grains and hop additions by carefully leaving them behind in the kettle.
Now is also the time to use a hydrometer to check the original gravity (OG) of the wort before fermentation begins. The OG is a reading that will be used with the final gravity (FG) to measure the alcohol by volume of the finished beer and the only true way to know when fermentation has been completed.
Add the yeast to the fermenter, put the lid on the bucket or use a rubber stopper if using a carboy, and install the airlock. Set aside in a cool dark area for 7 to 14 days, depending on the style of beer you are brewing.
After a week or so, take another hydrometer reading to see the progress of the fermentation. Once you have hit your target final gravity, it’s time to package your fresh beer.
Step 12: Bottle Conditioning
Once your wort has finished fermenting, it is now beer, but still needs a bit more time before it is ready to drink. Follow the recipe and the directions, but usually about 5-ounces of priming sugar is dissolved into 2-cups of boiling water for 5-minutes.
This liquid is then poured into a separate bottling bucket (yes cleaned and sanitized), and the fermented beer is racked on top of the priming sugar liquid.
Avoid stirring the beer as it can add oxygen which is not good for the beer. The flow of the beer from the transfer tubing will be enough to mix the priming sugar with the beer.
Finally, transfer your 5 gallons of beer to about 48 twelve ounce bottles and securely cap with crown bottle caps and a bottle capper. Now you need to put the bottles in another cool and dark area and wait 10 to 14 more days for the beer to naturally carbonate.
After the beer has carbonated, chill to your preferred drinking temperature and enjoy.
So there you have it.
Going from extract brewing to the brew in a bag method is a great introduction into the world of all-grain brewing, but with less equipment than the traditional brewing equipment.
When you brew in a bag, you still have full control over the recipe and the complete brewing process. BIAB will save you time because you will be eliminating specific brewing steps, and the prep-time and cleanup is much easier.
Plus it will save you money because you won’t need the extra equipment that is required for standard all-grain brewing.
Go ahead and give it a try on your next brew day.