It’s time for your first all-grain, BIAB brew! Today’s post is going to walk you through each step of brewing all-grain beer in a bag. We’ll be using a BIAB American Pale Ale recipe. For the full details, check out the recipe here. American Pale Ales are lovely, hoppy ales that balance malt complexity with a great hop kick up the butt. Nice!

It might also be a good idea to review the basic steps of all-grain brewing before going on.

First things first: Prep

Just like last time when we brewed the extract beer, good prep is key to a successful BIAB brew day. Here’s what to do:

  • Measure out the grains you’ll be using.Since this is an all-grain recipe, you’ll be using only grains and no extract. Make sure that the grains are pre-milled, or if you have a mill, now’s a good time to mill your grains. Don’t mill too finely. You’re really only trying to crack the grain hulls to expose the starchy goodness underneath.For this recipe, we’ll be using 3.55 kg (7.8 lbs) of 2-Row Pale Malt, 350g (12 oz) of Carared Crystal Malt, and 70g (2.5 oz) of Carafa Special III Chocolate Malt.

    All the grains mixed, milled, and ready to go!

  • Measure out the hop additions, and place them in order of adding (check out the recipe for the correct quantities)
  • Get the right quantity of water ready: about 27-29 litres (7.5 gal)
  • Clean everything, from the brew kettle (stock pot) to your spoons, whisk, fermenter,and measuring instruments.
  • Measure out and prepare other ingredients, like Irish Moss
  • Prepare the ice bath or wort chiller you’re going to be using.
  • Get a timer ready with all the steps you need to take into consideration.
  • Wash out the viole bag in hot water to remove any residual soaps / detergents
  • Get some iodine tincture from your local pharmacy. We’ll use this to test for full conversion at the end of the mash (more about this later).
  • Get your sanitation stationready. That’s a nice, big container filled with the sanitation of your choice (I recommend Perisan). Also, fill a spray bottle with the same.

Step 1. The “B” in BIAB.

First off, you need to fit the viole bag in your brew kettle. For this, you’ll need:

  • Your brew kettle
  • The viole bag
  • Binder clips
  • A small metal colander that can fit into a spare fermenter bucket as well as your kettle

Place the metal colander upside down in the center of the brew kettle. Now fit the bag into the kettle, and clip the top with your binder clips.

Finally position your kettle and bag on the burner or stove top. I recommend a low pressure gas burner, since it’s easier to control temperature this way. Second prize is your stove top, but temperature control during the mash can be a challenge, especially if you’re using an electric cooker.

Step 2. Heat your water.

Next, add 27-29 litres (7.5 gal) of water to your brew kettle. You’ll have to judge this based on the size of your kettle–remember that you’ll be adding about 4 kg (9 lbs) of grains, which will displace the water, so be cautious of adding too much H2O!

Bag in the kettle. Note those handy binder clips. The wire leads to a digital thermometer.

Our mash temperature for this recipe is around 66-67C (151.7 F). But, the grains we’ll be adding are at room temperature, and will, therefore, cool down the water. To hit the right temperature (referred to as your strike temperature), we’ll have to heat the water to 70-72C (160 F).

Step 3. Mashing In.

It’s time to mash in your grains. It’s a good idea to place all the grains we’ll be using into a bowl of some kind. That way, it’s easier to pour into the water. It doesn’t matter that you’re grains are mixed up–they’ll all go into the kettle (now a mash tun). Check the recipe for the grains that we’ll be using.

Important Caution: During the entire mashing process, you want to avoid introducing too much air into your grains and mash. So do everything gently and slowly. Don’t splash, don’t agitate, don’t breathe (just kidding about that last one).

Why? Getting air into the mash is referred to as hot-side aeration, a fancy term for oxygenating your as-yet-unmade wort and risking off-flavors and flavor stability issues down the line. To be fair, this is more of an issue for commercial brewers who deal with massive volumes of wort, but you can’t harm your beer by being careful.

So now that you’re sufficiently forewarned, you’re going to slowly pour the milled grains into the heated water. Have your brew spoon (or mash paddle) handy! Stir the grains gently. When you spot the occasional dough ball, eliminate that sucker.

Your goal here is to fully mix in the grains with the water, avoiding dry clumps. This is actually far easier than it sounds, mostly because you’re working with a large volume of heated water, which is one of the factors that make BIAB such a joy.

The grains busy mashing in. Note the closed lid. That’s to keep the heat in!

Once you’re grains are fully mashed in, check the temperature of the mash. It should now be really close to 66-67C (151.7 F). If not, you can either goose it a little by applying heat, or if its too hot, add some cold water.

Pro Tip: Keep some refrigerated brew water handy so you don’t have to add too much H2O at this stage.

If you’re happy with your temperature, close the kettle lid, turn off your burner or oven, and go have a beer.

We’ll be mashing the grains for 75 minutes.

Because of the large volume of water, your mash should stay at the right temperature for most of the mashing time (depending on ambient temperatures). Check it after 30 minutes or so, and adjust the temperature as needed.

You can also stir the mash gently once or twice during the 75 minutes to distribute heat more evenly, but don’t overdo it: we don’t want to aerate or cool down the mash!

At the end of 75 minutes, on, take a small, tablespoon-sized sample of the wort and put it in a bowl. Drip some of your iodine tincture onto it. If all has gone well, the iodine will remain brown. If not, it will color blue-purple.

If you get a blue iodine reaction, it means that the starches in your grains haven’t changed into sugar. You’ll have to extend your mash for another 10-20 minutes and re-test (also check whether your mash is in the correct temperature range. If it is below 55 C (131 F) or above 74 C (165 F), you won’t get much conversion happening).

The Iodine test. Brown = Good. Blue = Crying

Step 4. Mashing Out.

One of the downsides of BIAB is that you don’t always extract as much fermentable sugars from the grains as other all-grain methods. To counter this, you’ll be mashing out: that is, at the end of 75 minutes, you’re going to raise the temperature of the mash to 76C  (169 F) and hold it there for 10 minutes.

This step will help to extract more sugars, and aid in the next step, which is lautering.

Step 5. Lautering and Sparging.

When you use BIAB, lautering and sparging are as easy as lifting the bag out of the kettle. Yep, that’s as complicated as it gets!

Some BIAB brewers have taken to sparging more vigourously by washing the grain bag with sparge water. This will undoubtedly improve sugar extraction and increase your efficiency, but let’s leave that for a future post, shall we?

Because you’ve mashed out, the run-off from the bag will be less viscous and will, therefore, drain more sugars from the grains. Let the bag drain as much as possible, then stick it in a spare bucket. It’s a good idea to fish out your colander from the kettle and place that at the bottom of that bucket, underneath the bag.

The bag will slowly drain more sweet wort, and you can then add that to your kettle. Measure the specific gravity of the wort at this stage. If all went as planned, it should be in the region of: 1.038 to 1.040. If it’s much more than this, you can dilute it with some water. If much less, you’ll have to add some Dried Malt Extract during the boil. You’ll need about 500g of DME for every 10 points you’re off.

Now it’s time to continue with the regular wort boil. This step is identical to what you’ve already done with extracts, with the exception that no specialty grains are steeped, since their flavors have already been added in the mash. How cool is that?

Step 6. Boiling the Wort; Chilling; Fermenting

To save time and space, I’ll condense the next few steps and summarize what happens next. You’re going to:

  • Bring the wort up to a rolling boil
  • Add your first hop addition;  9 g Galena, @ 60 minutes
  • Add your second hop additions: 10 g Centennial and 10 g Mt. Hood, @ 20 minutes
  • Add 5 g Irish Moss @ 10 minutes
  • Add 15 g Mt. Hood @ 5 minutes
  • Add 28 g Cascade at flameout
  • Create a whirlpool
  • Add the final hop addition, 28 g Mt. Hood into the whirlpool
  • Measure your Original Gravity. It should be in the region of 1.046
  • Rehydrate the yeast in 120ml sterile water
  • Chill your wort to 27 C and pitch your yeast
  • Wait for beer to be created!

Wait for 2-3 weeks for fermentation and conditioning. Your target Final Gravity is around: 1.010-11.

Then bottle you beer, wait another 2 weeks, and enjoy! Let me know how it turns out!


  1. Charlie

    Brewing this as we speak. Will report back!

    • BrewerAdmin

      Thanks for that, Charlie! Let us know how it turns out and happy brewing!

  2. David W Hooley

    thank you so much for the Zoom conference today, i learned a lot. i am new to all grain brewing and have done 8 brews up to date. i have a 50L kettle and my wife made a custom brew bag to fit. i am now looking at getting a recirculation pump and modifying a 50L beer keg to suit. can you please give me some advice on how i whirlpool and what is needed.

    • BrewerAdmin

      Hi David. Thanks for attending, it was great to meet all of you! Well done on your setup, it looks like you’ll be brewing a lot of beer into the future! When it comes to whirlpooling, the usual way is to get yourself a very large whisk (the kind you can only buy in catering supply stores) and whisk the wort until a whirlpool forms. But with 50L of wort, that might be a challenge! So, since you’re getting a recirculation pump, you may be able to set it up to pump the wort from the kettle back into the kettle along the side, thus creating a whirlpool. A microbrewery I used to be part of had a kettle set up like that, and it worked pretty well. See if that works! Happy brewing and let me know how things turn out.

  3. Cainon

    Is this a 5 gallon recipe?

    • Harper

      Thanks for the question, Cainon! Yep, this is for a 5 Gallon batch. Hope it’s a good brew! Let us know how it turns out please.

  4. Hermann

    I only now noticed the use of the upside down colander in your kettle (don’t know how I missed it). Is this to prevent your bag from having ditect contact with the bottom and over heating?

    • Harper

      Hi Hermann. Yes, that’s exactly the reason. BIAB bags are not great with direct heat and can melt or be damaged. However, I have found that there is seldom a need to add heat to the mash unless you’re planning to add a mash-out stage at the end (i.e. raising to around 75 C). Then, a colander will be a good insurance policy (or anything else that will lift the bag from the bottom of the kettle.

  5. Hermann

    Thank you for the quick reply, I appreciate it.


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