Brew in a Bag (commonly referred to as BIAB) is a method of brewing that eliminates the need for a mash tun and consolidates brewing into a single vessel prior to fermentation. To understand how BIAB differs from other methods of brewing you must first become familiar with the language that brewers use (which is needlessly complex so apologies in advance) but more importantly how you make beer. If you know how beer is made then you can skip the next few paragraphs and jump directly to the ‘How does BIAB work?’ section.
In simple terms (and let me stress the simple aspect!) beer is made by introducing sugar to water then adding yeast and leaving it somewhere cool. The yeast ‘eats’ the sugar and converts it into alcohol. This, in a nutshell, is how you make simple alcoholic beverages. The sugars in beer come from a variety of sources but the foundation of any great beer is malted grains. Malted grains are simply grains taken from various crops (wheat, barley, rye etc.) that are then specifically cooked. The grains take on various properties due to the heat (the science is interesting but not necessary to know) that activate enzymes which break down complex carbs into simple sugars . Now that you have your sugar and water combined you introduce yeast and voila – you have beer.
Brew in a bag is a method of brewing all-grain. All-grain is a fancy way of saying that you are going to brew from scratch by first breaking the sugars away from your malted grains in hot water to get sugar-water. The sugar-water is known as ‘wort’ and that’s what we’ll refer to it as from here on out. To start a BIAB brew day you’ll need a few bits of equipment which I’ll list below:
Pro Tip: All of these items can be found in Homebrew Kits which are put together in order to help new brewers not have to decide what they need to get started! There are a few stages to brewing but BIAB cuts out a few steps to make brewing quicker, simpler, and easier. The aim of your BIAB brew day is to:
Look, I get it – I was impatient and eager to get started on my first brew – perhaps you’ve skipped straight to this section thinking you know everything you need to know about the theory. Maybe you’ve read the whole thing. Either way, you will make mistakes but you will learn from them! It really is very very difficult to completely ruin beer. So, with that in mind, let’s get started… Once you’ve chosen your recipe and decided on the measurements you’ll need to heat up som e water in your big ol’ soup pot. This is commonly called the ‘strike’ water. There are plenty of calculators online that will help you decide what temperature to heat your strike water up but the general principle is that it must be hotter than your mash temperature. This is because the addition of grains to that water will lower the temperature. A good rule of thumb is to have your strike water be 10F higher than your desired mash temperature. I hear what you’re thinking “Everybody talks about the mash… what the hell is the mash?”. In simple terms the mash is what you get when you combine your water and grains. Like adding milk to cornflakes it becomes a mushy mashed mess of gloopy horrible wetness. And then the magic happens as the sugars separate from the grains and give you your lovely sweet wort. Put the straining bag into the kettle with the strike water (remember to tie it to the handles so it doesn’t slip, oh and try not to burn your hands!) and slowly add your grains into the bag. Stir them as you add them so they don’t clump up in balls. Congratulations, you’re almost done with step 1! Check your temperature in the kettle and make sure you’re at the mash temperature your calculator has suggested. Too hot? Add a little cold water. Too cold? Heat up the kettle from underneath. Now, you’ve got to insulate the kettle as best as possible and allow the grains to mash (that is to steep at a specific temperature) and release their sugary goodness. I use blankets, towels, whatever comes to hand. Let the grains mash for however long your recipe says. Step 1 complete! (told you you were almost done)
With mashing done try and take a pre-boil gravity reading with your hydrometer. Hydrometers measure the gravity of the liquid which is to say how viscous (thick) it is compared to water. It sounds sciencey, and I suppose it is, but for beer purposes you don’t need to know the specifics behind it only the implications for your beer. Every recipe you look at will tell you the OG (original gravity) of the beer and the FG (final gravity). In a nutshell your wort should be made up of water and sugar. Sugar is denser than water so this will cause the liquid to become more viscous (thicker) – not syrup thick (if you’ve got syrup at this point something has gone wrong!) but thick enough that the hydrometer registers a value greater than water. The gravity of water is 1.000. Anything greater (1.050, 1.110 etc.) indicates there is something altering the composition of the substance (in this case, sugars) to make it thicker. Taking a pre-boil gravity will give you an idea of how efficient your mash technique is. Efficiency is something that homebrewers and commercial brewers alike strive to increase and it simply means “How good was your mashing technique and did you get all the sugars from the grains?”. The higher the value (which can be calculated using an online calculator) the better. Your first time you might not hit optimum efficiency. The second time you might not either. With every different style of beer you make you might not hit it. But remember, it’s really hard to mess up a beer and if your gravity doesn’t exactly match the recipe you’ve not failed – you might just have a less malty tasting or less alcoholic beer than you had expected. As the godfather of homebrewing Mr. Charlie Papazian says “Don’t worry, relax. Have a homebrew.” Once you’ve checked the pre-boil gravity it’s on to the boil. At this point you should only have wort in the kettle, no bag and no grains. Start heating the kettle up until you hit boiling temperature and then start your countdown keeping the kettle from boiling over but still having a consistent, rolling boil. Every recipe will differ in regards to hop additions, but remember, a "60 minute hop" is added at the very beginning. Its called a 60 minute addition because it boils for 60 minutes, not because its added at 60 minutes. So, using this logic, a 15 minute hop addition would be added 15 minutes prior to the end of the boil. Congratulations, step 2 is complete!
Once your boil timer is up it’s important to cool the wort down as swiftly as possible. Techniques include placing the kettle in an ice bath (remember to not scratch the bath and also… well… remember to get ice!), leaving the lid on and putting it out in the snow (if it’s that time of year) or using a wort chiller. It doesn’t matter which way you do it, you’ve simply got to get the wort down to a cooler temperature. Your yeast packet will likely tell you the optimum temperature for fermentation. Use this as a guide for the temperature you have to get the wort down to before pitching the yeast. Once it’s cooled it’s pitching time. Transfer, or "rack" as brewers say, the wort from the kettle into an empty FV and be sure to aerate it (that is, make sure it catches at least some air and bubbles!), and then drop in the yeast. Put the lid on top of your bucket (or bung if you're using a carboy), fill your airlock up to the fill mark with sanitizer, and fit the sanitizer into the hole of your lid or bung. Now place your FV in a cool place, preferably around 68F with most ales. Congratulations, you’ve just completed your first BIAB brewday! About the Author David Evans is a 30 year old cyclist who balances beer drinking and endurance riding by working out how many miles it'll take to work off a couple of Imperial IPAs... a keen homebrewer for just over a year with his best mate Paul, their attempts at IIPAs have been mostly successful, if overly ambitious!
All contents copyright 2024 by MoreFlavor Inc. All rights reserved. No part of this document or the related files may be reproduced or transmitted in any form, by any means (electronic, photocopying, recording, or otherwise) without the prior written permission of the publisher.
.png)
.png)
(1).png)
.png)
