BIAB guide for beginners.

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Oct 4, 2012
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Near Chester
Hello everyone! :hat:

Thought I'd drop by with a few photos and comments from my latest brew. I'm not an expert by any stretch of the imagination but the intention is to turn this into a basic how-to guide for BIAB in a way that can be followed by someone with some kit brewing experience. Also the images in the older guide on this forum seems not to have been archived properly so I think it may be useful to have a guide which includes photos. Also, when I started out I found it useful to have multiple sources of information. The existing guide was certainly a very useful guide in my first brew so I don't intend to replace it at all, but rather work alongside it! I collate my knowledge from reading said guide and other threads on this forum, from a Graham Wheeler book and from other assorted internet sites and forums, most of which I can't remember the name of.

I'll assume that the reader knows a bit about brewing already, such as what the basic equipment is for (hydrometers, airlocks etc), and the need to sterilise equipment. The glossary on this website is useful for those who aren't familiar with some of the terms I use.

The Recipe
The recipe I'm using comes from Graham Wheeler's "Brew Your Own British Real Ale" Third Edition, which I've found to be a very handy reference and covers a lot of information in a way which is accessible to a non-specialist such as myself! Also, given the large amount of malt used in the recipe I scaled it from 19L to 13L by multiplying the quantities by 2/3. Therefore the ingredients are:
Pale malt: 3000g
Crystal malt: 164g
Chocolate malt: 116g (All malts were crushed and milled.)
At start of boil:
Challenger hops: 16g
Fuggles hops: 8g
Last ten minutes of boil:
Golding hops: 8g
Irish moss: 3g
1x sachet of Safale S-04 yeast. I can't imagine that other ale yeasts would ruin the beer, but I use this as it's readily available from my nearest brewing shop and hasn't caused me any problems yet.
Strictly speaking the recipe also calls for dry hopping with "a few cones of" Styrian Golding hops, but I've omitted this as I didn't have any to hand and it's a long way to go to my nearest brew shop for such a small amount.

The Equipment
BIAB is a nice method that doesn't require a huge amount of expensive equipment, especially if you've already done a few brews from kit before. But here's a comprehensive list of everything I use here. Not all of them are essential; these ones are marked with an asterisk:
  • Boiler - I use this 30L Burco Cygnet electric boiler: Some people use stock pots on their gas hob.
  • Mesh bag - I use this as it's large, strong and has very small holes in it:
  • String - for tying up the bag so the grain can't escape during the mashing process.
  • Kettle or another method of generating hot water.
  • Fermentation bins and airlock (ideally 2)
  • Long handled plastic paddle or spoon - for doughing in the grain for the mash and aerating the wort. It could also be metal, but I wouldn't recommend using a wooden one as bacteria can lurk in the wood grain.
  • Colander* - useful for cleaning fruit and vegetables, but also handy while sparging.
  • Measuring jug - for making sure you're adding the right amount of water at all stages of the process.
  • Sieve* - used in sparging process.
  • Tin foil*- used in sparging process.
  • Sewing needle* - for poking tiny holes in the tin foil.
  • Thermometer - essential for knowing when your mash is at the right temperature and when the wort is cool enough to transfer from the boiler. I use a cooking one that you're supposed to stick into meat as it's accurate to a single degree Celsius and easy to read. It should be able to read temperatures below between around 20degC and 100degC.
  • Immersion Chiller/wort chiller/heat exchanger* - useful for getting the wort down to a temperature where you can pitch the yeast as quickly as possible. Mine is home made from copper tubing and runs off the outside tap. I may produce a guide on how to make this separately in the future.
  • Siphoning tube
  • Hydrometer
  • Trial jar* - Some may say this is essential but I only just bought one, having managed perfectly well for two years without!
  • A steel tray from a pressure cooker* - This is to stop the bottom of the bag coming into contact with the heating element of the boiler and burning the malt or melting the bag. Totally not essential as I've done two brews without it that haven't ended in disaster, but it's a precaution to prevent long term damage to the bag.
I know it sounds a lot, but much of this is already available to someone with some experience of kit brews and the rest can be found in most kitchens.

The Mash
The mash is where the grains are steeped in warm water to release sugars and flavour. This part is what separates BIAB from other all grain methods. Instead of steeping your malt in a separate insulated container, leaving it and then draining into another vessel the grain is held in a mesh bag in the boiler.

1) First off, heat up the correct amount of water in the boiler to around 70degC. In this recipe the specified amount is 12.3L but I'm reducing the quantity to 8.2L plus an extra one so that all the grain is covered, so it's 9.2L. I place the boiler on a Workmate as it's a stable and raised surface for when you siphon the cooled wort at the end of the process. You'll want to avoid moving the boiler as much as possible to avoid spillages. If you're using the steel tray I mentioned in the equipment section then now is the time to place this at the bottom of the boiler.

2) Next, hold the bag around the top edge of the boiler and put all the grains in. I alternated between 1kg of pale malt and then a speciality malt to try and get a nice even distribution of the speciality malts. Apologies in advance for the large pictures:

3) Using the paddle, 'dough in' the grain so that the water is freely flowing around the grain and all the grain is in contact with some of the water. At this point you'll probably notice the water is turning a pale brown colour.

4) Once this is done, keep the paddle in the bag and tie the bag off with some string. At this point you can start your timer for the mash. Many recipes say 90 minutes, some specify 60 minutes. Keep the lid on the boiler/stock pot during this time to help insulate it and help prevent any big nasty things getting in (such as insects or leaves if you are also brewing outdoors!)

5) Your aim is to keep the temperature of the water as close to the one specified in the recipe. Commonly this is 66degC but I read somewhere than something in between 62degC and 70degC is acceptable, so don't worry too much if you're not dead on. The boiler I use is thermostatic so I usually leave it on a setting I know is around the right temperature. Every ten minutes or so, give the bag a stir with the paddle and take a temperature reading. Adjust the thermostat up if it's too cold and down it it's too warm. I've found this is an effective way of moderating the temperature without requiring a really expensive thermostat or loads of insulation as you'd find in a mash tun. If you're using a stock pot on a gas hob then you'll probably be able to find a gas level that keeps the temperature just right, but it's good to give it a stir every now and then to keep the temperature uniform.

The Sparge
After the mashing time is up you're ready to sparge, which is where you pour hot water over the grain to release more sugars. Some people have really sophisticated methods to slowly distribute the water evenly over the grains such as in this video I just found: [ame][/ame]
As I'm not in possession of a suitable piece of equipment to sparge with, I improvise.

6) Take the bag out of the boiler and let the sugary water run from it into the boiler until it's just dripping a bit.

7) Place the colander into a fermentation vessel and then put the bag on top of that. This just creates some space for the water to drain into rather than staying in the bag. It's not necessary but I find it helps.

8) Now stretch the top of the bag over the top of the fermentation vessel. If you've used a colander then this shouldn't be difficult as the weight of the grain is supported by it.

9) Now here's the improvised (and potentially controversial) bit. The objective is to have hot water draining slowly and evenly through the grain in the bag. Initially I just used water from the measuring jug but I've since found that putting tin foil in a sieve and poking some hole through it works a bit better. In the future I intend to try connecting a funnel to a sprinkler from a watering can. There are multiple ways of doing this on the cheap and the limit is your imagination!


10) The amount of water you need varies on the recipe but ultimately you want a certain amount of beer at the end of the process and you will lose some when you boil the wort later on. Most recipes have a 'total liquor' value included in them. The difference between the 'mash liquor' and 'total liquor' is the amount I add during the sparging process. I also scaled this down from 16L to 11L as this recipe uses less grain. I find that my brews tend to be a bit short on volume (and high in strength) because I either don't add enough water when sparging or I lose too much during the boil.

11) The temperature of the water for sparging seems to vary depending on what source you read. Typically I see figures of 80degC and 85degC quoted so somewhere around there ought to be fine. I mix tap water and boiled water from the kettle in a 1:4 ratio and in theory that will produce 82degC water if my calculations are correct, assuming tap water is 10degC.

12) Take your time and pour the water over the grain as in the previous photo. I tend to transfer the liquid at the bottom into the boiler after 4 or 5 litres of added water. While you're doing this you may want to be heating the contents of the boiler up towards boiling point so there's less waiting around in step 13!

13) Once you've added the correct amount of water, transfer all of the liquid into the boiler and turn the boiler to full heat until it comes to the boil. In my case this means waiting around for ages as I'm terrible at estimating how long it takes to come to the boil. You don't need the grain any more so you can throw this away. The bag can be useful later so it's worth cleaning and sterilising it now.

The Boil

14) When the liquid is at a nice rolling boil, add your hops. The recipe will usually say which hops are at the start of the boil and which are to be added later. It's a good idea to weigh these out before the boil begins. I start the timer for the boil length (usually 90 minutes) when I add the first hops and then add the other hops when necessary. Keep an eye on the boiler while it's boiling to make sure it doesn't boil over or turn off. Mine sometimes needs resetting as turns itself off when on full boil for too long.

15) You may find that bits of hops will stick to the side of the boiler during the boil, if this happens I just push them back down with a paddle.

16) Usually in the last ten minutes of the boil the recipe calls for the addition of something called "Irish Moss" which is some kind of dried seaweed. This is a fining agent which, in theory, makes the proteins and bits of hop fall to the bottom of the boiler so they don't end up in your beer. I have made perfectly drinkable beer without this, but if you can get some then it does help.

17) When the boil time is done you can turn off the boiler/gas and now you need to cool the beer as quickly as you can to prevent infection before you pitch the yeast. Yeast doesn't respond well to high temperatures or rapid changes in temperature so you want the wort to be below 30degC. There are many methods of doing this. The worst is just leaving it to cool naturally, the best is with an immersion chiller. You can buy these for about £60 or make them for about £20. I've included a couple of photos of my home made one below.


If you use an immersion chiller then put it in the wort a few minutes BEFORE the end of the boil. This is so it's sterilised by the boiling water. Beware of steam coming from the in and out pipes when you do this. The idea of the immersion chiller is to pass cold water through a network of copper piping immersed in the hot water. The heat will flow into the cold water and then get taken away down the drain. I've found that a brew can be brought down to temperature in about 20-35 minutes using this method.

18) Once you've cooled the wort down to below 30degC you can transfer it to a fermentation vessel. I use a siphoning tube, some people fit their boilers with a device called a hop strainer so that they can use the tap provided with it. In my experience if you try this without a hop strainer you will clog the tap with hops. You can use the bag here to catch any bits of hop that come through the siphoning tube if you stretch the bag over your FV.

19) When all of you wort is in a FV you can pitch the yeast, fit the airlock and wait. Take a measurement of the original gravity of the beer with your hydrometer. In this case it's supposed to be 1.058 but I got 1.063. the final gravity was supposed to be 1.015 but I ended up with 1.013. As a consequence my version of Old Peculiar is about 1% stronger than normal. The process from now on is the same as a kit beer in terms of conditioning and bottling. Generally 'cask' (e.g. a secondary FV) conditioning for about three weeks and then bottle conditioning for another three weeks will be enough time.

20) Enjoy your beer - you've earned it!

A few closing thoughts
  • This process takes time. Weighing the ingredients takes me about an hour, mashing takes 90 minutes, boiling takes 90 minutes, sparging takes me and my dad about 45 minutes, cooling takes at least 20 minutes, so assuming everything goes to plan it will take at least 5 hours so plan ahead and make sure you don't have too much to do.
  • While I've assumed that the reader knows about sterilising equipment I'd like to reiterate that after the boil has finished EVERYTHING that comes into contact with the beer must be sterile. Prior to the boil you can be a bit more relaxed, but I try to maintain the same levels of cleanliness as a good practice.
  • My most recent brew, which is the source of the images here, took four days to ferment (From the 2nd of October 2014 to the 6th) which I found to be exceptionally rapid compared to the wines and ciders I normally do, therefore keep an eye on how active the airlock is and take hydrometer readings when it starts to slow down. Although it's still early days and I'm currently in the conditioning process, the samples I've tried so far have been really good.
  • I've heard a few people say that 'once you go AG you'll never go back' and I have to agree with them. I'm only on my third AG brew and I'm already producing beer than I would be happy to pay normal prices for in the pub.
  • I hope this guide is clear, I may make revisions and additions to it if people feel certain parts are not quite as clear as they could be (or incorrect!)
  • Please feel free to distribute this text as you see fit for non-profit purposes. I would greatly appreciate being notified and acknowledged if you do so! :)
  • I should acknowledge my dad as my 'lab assistant' here. He built the immersion chiller and helps with the brewing process. There are some things that in this process that are difficult to do with one pair of hands, so if you have a significant other/child/parent on hand then by all means recruit them in the process - it's a good bonding experience, I find!

Phew - I pretty much got through an entire bottle of Wilkos Chardonnay while putting this together! I really hope it is of use to somebody somewhere and encourages them to take the brave step into the world of all grain brewing. It takes a while to understand the processes and why each step is important, but when you taste the results it is absolutely worth the effort.

Cheers - I open the floor for comments/suggestions/spelling corrections/grammar corrections :drink:
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10 Gallon Tosspot
Oct 7, 2014
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Liverpool, UK
Beautifully written and easily understandable guide for BIAB users!

I'm planning my first ever all grain BIAB brew in a week or so, so I'll be using this guide to reference.

Will let you know how I get on, thanks!


Oct 4, 2012
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Near Chester
Beautifully written and easily understandable guide for BIAB users!

I'm planning my first ever all grain BIAB brew in a week or so, so I'll be using this guide to reference.

Will let you know how I get on, thanks!

Thank you for the kind words and good luck. If you encounter any problems I'm sure there'll be someone on here who will be able to help.

Mr Sworld

New Member
May 21, 2011
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Nice. I've been looking at getting into AG and this looks like an excellent way to start.



New Member
Mar 10, 2014
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Can I just add a note of thanks to this guide. Did my first BIAB today using this method nearly exactly and I can tell its going to be great - that real beer taste of sweet malt/bitter hops and flavour I just didnt seem to get with extract.

The only thing I feel is a bit complex is how much water to use - I scaled down a recipe to 13l but clearly didnt use enough sparge water and didnt realise how much was lost in the 90 minute boil. I topped up to about 11.5 litres with water and the OG was 1047 so pretty pleased with that though.

thanks again

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