Brew in a Bag (BIAB) Primer By: Ron Witkowski

Brew in a Bag (henceforth referred to as BIAB) is a method of all-grain brewing requiring minimal setup and investment when compared to traditional all-grain brewing.  BIAB has some advantages and disadvantages when compared to traditional all-grain brewing which we will cover today.  In addition there are varying methods of BIAB (e.g. Sparge / No-Sparge) that you may customizes to fir your brewing style and preference.  BIAB is a great way to get into all grain if you are a little strained for space, somewhat tight on budget, or if you just want to make your all-grain brewing a bit more convenient in return for some adjustments in recipes and technique!

Let’s start with the equipment you’re going to need to BIAB.  All of the equipment documented in our photos is available here at love2brew!

·         Brew Kettle (10 gal. minimum for a 5 gallon batch)  BIAB  |

·         Burner – We currently sell Blichmann burners and are working on getting them on the site; please contact us for info.  (Note:  This should technically read a source of heat; technically you could do BIAB on your stove but we highly recommend against it due to the amount of excess time and inconvenience wasted.)

·         Large Grain Bag – We use these large straining bags and they work great.  Depending on your kettle size they may/may not fit completely around your kettle.

·         Mash Paddle

·         Thermometer

·         Method to transfer your wort – Auto-Siphon or a kettle with a Ball-Lock Valve will also work.  If brewing with friends multiple people may also funnel the wort directly from the kettle into a your carboy.

·         Wort Chiller – While not necessary the amount of time and money (ice) necessary to chill a full boil BIAB is not worth the stress.  You’ll thank us later! 

·         Method to Strain Grains (more on this later)


When using the BIAB you will need to make some modifications to your brew day in order to achieve the best possible results.  Today we’ll be discussing a no-sparge BIAB method so I will address the adjustments accordingly.  Our biggest challenge with a no–sparge BIAB brew is efficiency; there are several steps in our process that if not properly accounted for will reduce the overall efficiency in our batch.  The good news is that there are some easy solutions to increase our efficiency using this method.
1.     Crush grains very fine:  Often referred to as a “double crush”, your objective is to have a very fine crush on your grains to allow more of the sugars to be extracted.  Here at the shop we will run the grains through their standard crush and then re-crush the already crushed grains again. 
Note the fine crush in the malts.

2.     Increase grain volume:  Although not always a necessity increasing the amount of grains in your recipe will help to recover lost efficiency.

3.     Increase water volume:  In the example we will cover today we started with 9 gallons of water.  We started with this much to account for the water absorbed by the grains and the amount of water we would lose in the boil.  We ended up with a little over 5 gallons so if we were to redo this recipe we would start with 8- 8.5 gallons for this 10 lb. grain batch.  In another recent batch we mashed 12 lbs. of grain and used 9 gallons which turned out perfect.

4.     Increase mash time:  Here at love2brew we BIAB with the following schedule; 70 minute mash and a 20 minute mash out.

5.     Mash Temperature Range:  Because we’re mashing at a high water to grain ratio we need to be conscious of our mash temperature.  This ratio can create more dextrines in a finished beer which may result in a thicker body at higher temperatures and a think mash at lower temperatures.  We recommend you keep your mash temperatures around 150-156°F.

Once we’ve accounted for these modifications in our technique we’re ready to move forward with our brew!

The Brew
1.     Preparation:  Line the kettle with your bag.  In our case we’re using a 15 gallon kettle so our bag will not fit properly around the entire edge.  We have two potential options in this scenario; a.) we can insert the bag into a turkey fryer and insert the fryer with grain bag into the kettle or b.) Clip the bag to the kettle.  We opted for option B but only because we did not have access to a turkey fryer at the time.
2.      Strike Temperature:  We’re going to start by bringing up our water to our strike temperature (strike is the temperature of you water in your mash tun (in this case our kettle) before adding grains).  We mashed at 154°Fso our strike temperature was 162°F


Grain additions

3.     Mashing:  At this point you may turn the heat off on your burner and slowly add in your grains while stirring with your mash paddle.  As you add your grains be sure to stir with your mash paddle to avoid clumping and dough balls in your mash.  If brewing with friends you may have someone pour the grains in and someone else stir the mash.

a.     At this point you should be checking your temperature.  If the temperature is too low you may turn the heat source back on until your target temperature is reached.  If it is too hot you may add a little bit of cold water.  Be careful with the water additions as you are beginning with all the necessary water volume from the start of your batch. 

b.    With the method we are reviewing today you’d rather risk being under target mash temp instead of over.  We had no issues hitting our mash temp correctly.

c.     Cover your kettle with a blanket/towel/etc. to help maintain your mash temperature.  You will mash for 70 minutes.  Be sure to periodically check your temperature to ensure consistency.
BIAB  |                                         BIAB  |
4.     Mash-Out:  After 70 minutes of mashing you will bring the temperature of your mash to 170°F to complete your mash-out.  Just like our mash we recommend increasing your mash out time from 10 minutes to 20 minutes in order to achieve the highest efficiency possible with this method of brewing.
5.     Draining of Grains:  Upon completion of your mash out you will need to raise the grains out of your kettle.  Depending on which guide to BIAB you’re following you may hear some different methods of achieving this.  Some people have built a hook/pulley system that enables them to use minimal manpower; this is definitely something you should research if you often brew alone.  Lifting a soaking wet bag of grains by yourself out of a mash tun can be very challenging since you’re pulling it from the top of the bag.  Here at love2brew it’s a rarity to brew alone so we improvised a method that was significantly quicker than building a pulley system.  First we cleaned off our mash paddle and then tied the bag in a knot around the center.  Then we put up two wooden dividers (we had them left over from shelves) on both sides of the kettle and hung the paddle on the two of them.  This allowed the wort to drain from the bag back into the kettle.  After the wort drains you may press slightly on the bag to drain any remaining wort out.  When you’re done you may dispose of your grains or use them for some delicious dog treats!
6.     Record Results:  If you would like to measure your efficiency you may take a gravity reading at this point.  (More on that in a future article)
7.     The Boil / Cooling:  At this point you’re ready to bring your wort to a boil; everything from here on out is just like an extract batch!  Bring your wort to a boil, add your hop additions at the correct times, boil for 60 minutes, and then cool to 70°F!  Take your gravity reading and move forward.
Addition of wort chiller at the end of the boil for sanitation

8.     Transfer to Carboy / Pitch Yeast: After cooling transfer your wort to your carboy.  There are a number of methods to do this; if brewing alone we highly recommend using an auto-siphon or if your kettle supports it just racking directly from the spigot into your carboy.  In our specific case we had multiple people around for our brew so in order to get some great aeration in our wort (which Kay just wrote a great article about here) we used an anti-splash funnel and multiple people to carefully pour the wort into our carboy.

Fermenting away the next day!

That pretty much sums up BIAB!  This guide is meant to serve as a primer; as with most aspects of brewing there is a lot to learn outside of the basics.  We’re confident that this guide will serve you as a basis of BIAB.  If you have any questions or comments feel free to add them below!