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How To Easily Brew All-Grain Using The BIAB Method

biab mashing

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 that is looking for an easier way on brewing day, using the “brew in a bag” method, or also known as BIAB, 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.

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 brewing.

Table of Contents

What Exactly Is The Brew In A Bag Method?

BIAB is a simple and cost-effective way for any homebrewer to enhance their brewing skills without all the extra equipment. In addition to your standard extract brewing equipment, you also need a large kettle, mash tun with a false bottom, and a hot liquor tank.

But with the BIAB 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, and a brew bag or a large nylon grain bag.

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.

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.

  • Large Brew Kettle:  It is a good idea to have a brew pot that is double the size of the batch of beer you are brewing.  So for a 5-gallon beer batch, you should get a 10-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.
  • Heat Source:  Because of 5-gallon extract recipes call for a partial boil, most kitchen stoves can bring the liquid 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.
  • Brew Bag:  As is with most products, you usually get what you pay for, and a brew bag is no different.  Brewing bags come in various sizes and made of different materials.  When BIAB, you will want to get one that has a fine mesh that will catch as much of the crushed grains as possible.  A good quality brew bag can last for hundreds of brews if taken care of.
  • Clamps To Secure Bag To Kettle: 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 inexpensive clips is a wise choice.
  • Draining Rack or Pulley System: You will need a way to lift the heavy 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 grill grate with do just as good of a job.
  • Wort Chiller: Just like any batch of beer, you want to get the wort down to yeast pitching temperature quickly as possible. For partial boils, using an ice bath can do the trick, but for a full volume boil, a wort chiller is recommended. A wort chiller can get the wort temperature down within 15 to 20 minutes.
  • Thermometer: 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 temperature of your mash is.

Standard Brewing Equipment You Probably Already Have On Hand

  • Primary Fermenter – Plastic Bucket and/or Glass Carboy
  • Airlock
  • Stirring Spoon
  • Cleaner and Sanitizer
  • Hydrometer (Optional)
  • Bottling Bucket
  • Transfer Tubing
  • Bottling Wand
  • Bottle Capper and Caps
  • Glass Bottles

Pros of Brewing In a Bag

There are quite a few advantages of using the BIAB 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 and Hot Liquor Tank)
  • Requires Less Space
  • Less Equipment To Clean and Sanitize – (Woo Hoo)

Cons of Brewing In a Bag

  • Lose Some Efficiency In The Mash
  • Mash Temperature Can Be More Difficult To Control, especially when brewing in colder environments.

Step-By-Step 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 Your 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. 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 Strike Water

You need to figure the amount of pre-boil water you will need to begin with for the beer batch size you are brewing.  You will 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 temperature.

Not to worry.  You can find a number of online brewing calculators to help you get these 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 and/or 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.

putting barley in a grain mill hopper

Step 4: Adding Grains To Kettle and Mashing

After the strike water has reached the calculated temperature, put your nylon brewing bag inside of the kettle and begin to add the grains.  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 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.

biab mashing

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.

Step 6 : Removing the Bag

After the mash or mash out, time to remove the brew bag from the pot, and depending on your specific grain bill, the bag is heavy and could weigh as much as 20-pounds.

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 lift the heavy brew bag from the brew kettle.

We find that the easiest and most simple way is to grab a partner, lift the 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.

draining grains after mashing

Just remember to use a pair of brewing gloves, when squeezing the hot bag, or you can even use the lid from the brew kettle to push on the bag to extract as much liquid as possible.

Step 7: Sparging (Optional)

Sparging is a standard step in all-grain brewing, but it’s not required when brewing in a bag.  Sparging is when you use warm 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, but it is 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: The Boil

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 first hop addition.  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 hops 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:

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.

picture of immersion chiller in wort

One popular way is to submerge the brew kettle in a ice bath while continually adding fresh water and new ice 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.

cooling wort in an ice bath

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.  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 that the jug you are using is a food-safe 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, while leaving as much of the hop sediment 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, but is totally optional as well.

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 that is filled with star san or vodka.  Set aside in a cool dark area for 7 to 14 days, depending on the style of beer you are brewing.

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.

Bottle conditioning and carbonation

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. Finally!

Happy Brewing!


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