A Guide to Mini-BIAB

Post #1 made 10 years ago
[center]BIABrewer Note: All brewers, new and experienced, are encouraged to start new topics in this section provided they have read the below.[/center]

[center]A Guide to Mini BIAB
by Ralph deVoil (Ralph)

This guide describes the making of All- Grain beer with the most basic, domestic kitchen equipment with no complicated processes whatsoever. This is the simplest BIAB anyone could possibly undertake, but it nevertheless has the potential to produce some of the finest beer.

Experienced all-grain brewers should also consider using this method to brew small batches of experimental beers.

In this guide, we will use a 19 litre pot to brew 9.5 lts of American Pale Ale - NRB's All Amarillo APA.

The following guide is laid out in a similiar manner to BIAB - The Master Guide. Readers seeking further information on any area should be familiar with The Master Guide and refer to it where further clarification is required.

This guide is made up of the following posts...

Mini-BIAB Equipment
Scaling Recipes to Mini-BIAB Size

Please feel free to ask any questions in this section.

Happy brewing,

All brewers, new and experienced, are encouraged to start new topics in this section provided they have read the steps below.
Last edited by Ralph on 03 Apr 2010, 13:29, edited 11 times in total.

Post #2 made 10 years ago
[center]Mini-BIAB Equipment[/center]

As can be seen from the below, nearly all Mini-BIAB equipment can be found around the home or acquired with considerable ease. To brew our American Pale Ale (APA), we will need the following...

Heat Source

Usually a domestic gas or electric stove-top is sufficient for Mini-BIABs. The heat source just needs to be capable of boiling around 15L of water. Occasionally it is possible to utilise two elements or gas rings though generally the big one is sufficient. Some brewers have used the BBQ for heating which can be handy in moving everything out of the kitchen.

Stock Pot/ Kettle

This guide uses a 19L stockpot as the kettle. This is a size that is widely available. Larger stockpots are fine although your stove-top may be incapable of boiling more than 15 or 20L. Before brew day, experiment to see how much hot water you can bring to the boil within say 25 minutes. Tall narrow kettles are better for mini-BIABs than wide squat ones due to the decreased evaporation rate. Also, thoroughly test the handles of the pot for strength and integrity, it will have to picked up when full.


A BIAB bag can be made simply as is shown in FAQ: Should I make a bag or can I buy one? Make your bag to the correct dimensions by following the formulas in that thread. Some home brew retailers sell a bag made up, perhaps order your milled grain, hops and yeast along with a BIAB bag all from one supplier.

Accurate Measuring Jug

An accurate measuring jug is essential to get our volumes correct. A 5L jug available at good home brew stores is an ideal choice.


An accurate thermometer is a must for any type of all-grain brewing. [EDNOTE: Link needed.] This thread shows a cheap and reliable thermometer that is suitable for stove-top brewing. The alcohol thermometers seem to be fine, a few also use infra-red thermometers but you'll find they don't work on many common surfaces in a brewery (eg. stainless) so do not rely on it for mashing.

Domestic Kettle

A domestic kettle is not essential equipment but can be used to speed up some parts of the brew day.

Laundry Tub or Kitchen Sink

Either of these can be used to chill the wort after the boil. Laundry tubs are usually better than kitchen sinks due to their larger volume.


A kitchen sieve of about 200mm (8”) diameter with a handle that can sit in the opening of your fermenter is ideal. Chilled wort will be poured through this into the fermenter so as to filter out some hop debris and kettle trub.

Mash Paddle

A large spoon or ladle works well as a mini-BIAB mash paddle.

Here is picture of most of the equipment required (not shown- domestic kettle, measuring jug, laundry tub.)
Last edited by Ralph on 03 Apr 2010, 14:13, edited 12 times in total.

Post #3 made 10 years ago
[center]Scaling Recipes to Mini-BIAB Size[/center]

Most recipes found by brewers are written for batches much larger than mini-BIABs. For example, the volumes listed in the APA recipe we are using for this guide are much too high for our mini/ domestic equipment.

The Calculator can be used to scale recipes.

[EDNOTE: Example of how to convert recipes needs to be written.]

Our new mini-BIAB APA recipe will now look like this one.
Last edited by Ralph on 03 Apr 2010, 14:13, edited 11 times in total.

Post #4 made 10 years ago

Follow the steps in The Checklist. Being prepared in advance and using a BIABrewer Checklist will help your brewday be free of hassles or mistakes and run more smoothly.

Pausing to make sure everything is in place and working well is one way to make sure your first All- Grain brewday is a complete success. The process itself is well- tested and works just fine, so if you have all of the right ingredients and equipment working, then there's nothing to stop you from starting to BIAB!


If Mini-BIAB is your first foray into All- Grain brewing, it is unlikely that you will have access to accurate scales or a grain mill. An enthusiastic retailer will help you out here but consider paying them extra as the profit on weighing and and crushing a fairly small amount of grain will probably not cover their cost in time.

Some enthusiastic suppliers will however sell pre- milled and pre- mixed grain in a packet all ready to just add to the mash. A standard crush or finer is perfectly okay for BIAB.

Hops, Yeast and Miscellaneous

Make sure you purchase a packet of hops, we recommend steering clear of expensive smaller quantities such as the hops tea bags with about 12g of hops and getting the 50g, 90 or 100g packs for some economy. Don't forget the sachet of dried yeast as well and, importantly, store them all in the refrigerator.

The Yeast Nutrient and Whirfloc listed in the recipe can be skipped initially although they are wise additions to your inventory in the long run.


It is worthwhile checking your equipment in a wet test run, i.e. with just plain water.

So, add 2/3 kettle- full of water to the kettle and give it a test boil. Note how long it takes to bring the water to strike temperature and then how much longer to reach boiling, this will give you some ideas on how long your brewday is likely to be and help with your planning, plus confirm that the heat source is adequate for the task. If you are using a stand- alone gas burner, make sure you have enough gas in the cylinder to run it for at least three hours.

Test the kettle/stockpot handles too, so fill it right up and try lifting it, if the handles are able to pick it up full of cold water then that's great, because later on you're going to pick it up about 2/3- full of hot liquor after mashing and about 1/2- full of near- boiling wort at the end of the boil. A pot of near- boiling wort can be quite a problematic thing to handle, so make sure you properly assess all of the risks in this operation.

It won't hurt to calibrate your kettle beforehand. Use a stainless steel ruler to work out how many mms of the ruler each litre covers. (Yhis figure should closely match the Kettle Calibration Figure found in Cell D26 of The Calculator.
Last edited by Ralph on 03 Apr 2010, 14:13, edited 11 times in total.

Post #5 made 10 years ago

Just as explained in The Master Guide, our brew day begins when we add water to the kettle (our stock pot.)

Adding the Water

The Calculator we have completed tells us "Water Required is..." 18.49L. Our, "Approximate Mash Volume," shows a figure of 20.13L so if we added all 18.49L to our kettle, it is likely that when we add our grain, the kettle will overflow.
To avoid this, I am going to only initially add 15L of the 18.49L required. Using my 5L measuring jug, I will add 15L to the pot and apply maximum heat to it. You can of course, speed up this process a little by adding say 10L to the pot and boiling the last 5L in your domestic kettle and then adding it to the pot as it heats up.

Heating the Water to, "Strike," Temperature

Our recipe asks that we mash (soak) the grain at a temperature of 65°C. As explained in The Master Guide, when we add our grain, the temperature of our water drops by a few degrees. To compensate for this we heat our water to, "strike," temperature. For Mini-BIABs we recommend a strike temperature of 3°C above mash temperature. For our APA we therefore need to heat our 15L of water to 68°C. Regularly stir the water and check the temperature while waiting for it to reach strike temperature.

Adding the Bag and Grain

As soon as your water has reached 68°C, slip your bag into the pot and secure it firmly around the rim of the pot.

Now slowly, "rain in," the grain. To do this, hold the container of milled grain above the pot and slowly pour it in while gently stirring the mash around to submerge the incoming grain.
Here is a picture of raining in the grain...
Once you have added all the grain, we'll add the remaining 3-odd litres of water to fill the pot right up, however we need to know what temperature it has to be at, so give a further brief stir and then check the temperature reading. It is very likely to be within a degree or two of your desired mash temperature, this is great and if so, add the additional water at the mash temperature, if the mash is slightly cooler than the target add hot water etc.

Stir again then remeasure the temperature. If the mash is slightly hot, just leave the lid off the pot until the mash reaches the desired temperature. If it is too cool, apply heat while continually stirring the mash until mash temperature is acquired.*

You have a couple of options now, either leave the pot uninsulated and add some heat occasionally as it cools down, or insulate the pot with a jumper/ towels/ doonah as per Beachbum.

[center]You must always stir the mash when applying heat otherwise your bag will burn.[/center]
I prefer to just insulate the pot while it is mashing, I find temperature losses are only a degree or so if well- insulated, that is fine in most circumstances.
Last edited by Ralph on 03 Apr 2010, 14:13, edited 12 times in total.

Post #6 made 10 years ago

Follow the procedures recommended in The Master Guide. Basically during the 90 minute mash all we have to do is stir the mash occasionally and then check the temperature, applying heat when necessary. Keep in mind that every time you lift the lid off the pot you're losing heat, while stirring it too frequently will result in high heat losses too, so just be patient.

To finish the mash, use the Pulling the Bag by Hand method that is outlined in The Master Guide.
Last edited by Ralph on 03 Apr 2010, 14:13, edited 11 times in total.

Post #7 made 10 years ago

At the start of the boil, take a sample, cool it and measure the Specific Gravity with your hydrometer or refractometer. Also measure the volume. These values will give you an idea of the "efficiency into kettle." In this case I'm expecting a Pre- Boil SG of low 1.040s, it was 1.044, so quite a reasonable yield. The SG will increase as the boil progresses due to evaporation of water and concentration of the sugars in the wort.

So, put the pot on the stove and crank up the heat to boil the wort. Keep an eye on it as a boil- over is a distinct possibility. You'll see foamy scum forming, that can be skimmed off and discarded if you like. Once the wort actually starts boiling, that's when your boil time can start to count down, we're doing a 90 minute boil here with our first hops addition at 75 minutes, that's it in the plastic container below just about to be added.

One major purpose of the boil is to evaporate off undesirable flavours so it is important to allow the steam to escape.
Last edited by Ralph on 03 Apr 2010, 14:14, edited 11 times in total.

Post #8 made 10 years ago
Ok, the boil is finished. Take another gravity and volume reading so as to determine your efficiency at end of boil.

Leave the kettle on the stove for about 15 minutes and then move it to the laundry tub or sink to chill. (Make sure you have tested the handles of your pot with cold water as explained here.

With the pot moved carefully to the sink, add the cold tap water until it just about floats. Obviously we don't want it to float and risk tipping over though. After 20 minutes, change the water.
Change the water again when it gets hot, say another half an hour, the sooner we get the wort temperature down to pitching temperature the better, today it is an ale so that's 18 C.

It is vitally important to not infect the wort, so leave the lid on while it cools, no matter how tempting it is to lift it off and have a whiff. Chances are, you'll introduce airborne bug which will ruin the whole batch. Just leave it be!

We need the wort to be at around 18C for pitching, so keep changing the water as often as you see fit. This kettle- chilling is just so easy, particularly for new brewers as there's really no equipment to worry about apart from the stockpot and somewhere to chill it, but it can be wasteful on water.
Last edited by Ralph on 03 Apr 2010, 14:14, edited 11 times in total.

Post #9 made 10 years ago
Once the wort is cooled in the tub or sink, it is time to empty the stockpot into the fermenter.

What we'll do is take our sanitised fermenter and sieve, sit the fermenter on the floor (with the tap shut) and the sieve placed in the top of the fermenter. Carefully take the lid off the stockpot, lift it out of the tub, and pour the wort into the fermenter through the sieve. The hops debris will acumulate in the sieve but stop pouring before all the break material (tan- coloured muck) pours though. Some break will make it though, don't worry too much, but stop with about the last litre* or so of thick muck remaining in the stockpot. You're done! Congratulations, welcome to All- Grain brewing! Now pitch the yeast and relax.
If you haven't got the Post- Boil SG sample, now is a good time to get one. It should be in the low- 1.050s if everything went to plan for the demonstration recipe.

*That last litre or so of wort in the stockpot can be filtered and used for liquid yeast starters.

Happy brewing :)
Last edited by Ralph on 03 Apr 2010, 14:14, edited 10 times in total.

Post #10 made 10 years ago
[center]To provide Feedback or ask Questions on the Guide to Mini-BIAB, please use this thread.[/center]

Many thanks to Ralph for providing the above guide. Please use the thread linked above to provide feedback or ask any questions on this guide. Your feedback and questions will help identify if any aspects of the guide need clarification etc., after which Ralph may allow us to use it as an official BIABrewer guide/ADO - fingers crossed.

Thanks so much for spending this time Ralph and sorry we locked the topic without advising members how to give feedback etc. (We'll get it right for your Maxi-BIAB guide though :).)

Great job!
Last edited by BIABrewer on 30 Aug 2010, 18:27, edited 10 times in total.

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