Author: AHB Brewing Team Date Posted:2 June 2026

BIAB (Brew in a Bag) is the most accessible way to start all-grain brewing at home. One pot, one bag, and full control over your grain bill ,this guide covers everything Australian home brewers need to know.

Brew in a Bag (BIAB): The Complete Guide for Australian Home Brewers

BIAB (Brew in a Bag) is a single-vessel all-grain brewing method. You mash malted grain directly in your pot (kettle) using a fine mesh bag, lift it out when you're done, and boil the wort in the same vessel. One pot, one bag, complete control over your grain bill.

BIAB appeals to a particular kind of brewer: someone who wants to work with malted grain, design recipes from the ground up, and engage with the full technical process of converting starches to fermentable sugars. That relationship with the process is the win. The beer it produces is excellent, but so is a well-executed extract or kit brew. The difference is in what you do to get there.

One of BIAB's real advantages is its accessibility. If you already have a large pot, basic fermentation gear, and a stove, your main cost for a small experimental batch is the ingredients and a bag. There's no reason to invest in specialist equipment before you know whether the process suits you.

Key Takeaways
BIAB is a single-vessel all-grain method using a pot and a bag — a distinct brewing approach with its own satisfactions
It does not automatically produce better beer than a well-executed extract or kit brew. The difference is the process, not the result.
Small experimental batches can be done in a large pasta pot on your stove — no specialist equipment needed to get started
Ingredient costs vary by batch size; AHB all-grain recipe kits range from around $60 to $90
Mash temperature sits at 65–67°C for most Australian ales; hold it stable for 60 minutes
AHB stocks BIAB bags, all-grain recipe kits with freshly crushed malted grain, and individual grains for those building their own recipes — with a crushing service available

What is BIAB and who is it for?

All-grain brewing uses malted barley instead of malt extract made by a brewery. The brewer controls the mash: converting starches to fermentable sugar in hot water, which determines fermentability, body, colour, and flavour at the source.

Traditional all-grain setups use three vessels: a mash tun, a hot water vessel, and a pot (kettle). BIAB simplifies this significantly. A single pot does the whole job: the BIAB bag goes in, the grain goes in, temperature is held, and the bag is lifted out when the mash is done. The wort stays in the pot and goes straight to the boil. For someone curious about all-grain brewing, this means you can experiment without committing to a three-vessel setup or the space it requires.

This matters for Australian home brewers because BIAB fits the typical home setup well. A large pasta pot on the stove is enough to try a small batch. If you want to brew 19–20 litres at a time you'll need a bigger pot, but the principle is the same.

BIAB is not for everyone, and that's worth saying up front. It requires a brew day of several hours. There's more to clean, more variables to manage, and a steeper learning curve than kit or extract brewing. Most home brewers who are producing excellent beer every batch have no reason to switch, and plenty of reasons to stay where they are.

The honest appeal of BIAB is this: if you're the kind of person who wants to build a recipe from scratch, understand every decision that shaped the beer in your glass, and engage with mashing and fermentation as a craft in itself, then BIAB gives you that. It's a different relationship with the process of making beer.

Start Here
For your first BIAB batch, a simple pale ale or an Irish stout is the right call. Both have forgiving grain bills, a clear flavour target, and enough character to make the result genuinely satisfying. AHB all-grain recipe kits contain freshly crushed malted grain, Whirlfloc tablets, and instructions — everything you need except the pot and the yeast.
If you brew extract kits and want to experiment with grain without committing to a full BIAB setup, you already have options. Mini-mashes, dry hop additions, and grain steeping can all be done with your existing equipment. Many extract brewers incorporate grain regularly and find it gives them everything they want. Fresh Wort Kits are also worth a look — you ferment actual brewery wort at home, no mash required, and the results are outstanding.

Start Here

For your first BIAB batch, a simple pale ale or an Irish stout is the right call. Both have forgiving grain bills, a clear flavour target, and enough character to make the result genuinely satisfying. AHB all-grain recipe kits contain freshly crushed malted grain, Whirlfloc tablets, and instructions — everything you need except the pot and the yeast.

If you brew extract kits and want to experiment with grain without committing to a full BIAB setup, you already have options. Mini-mashes, dry hop additions, and grain steeping can all be done with your existing equipment. Many extract brewers incorporate grain regularly and find it gives them everything they want. Fresh Wort Kits are also worth a look — you ferment actual brewery wort at home, no mash required, and the results are outstanding.

What equipment do you need for BIAB?

The short answer is: you may already have most of it. A large pot, a stove, and basic fermentation gear are enough to brew a small batch. The BIAB bag is the one piece most people don't own already, and it's inexpensive. AHB stocks BIAB bags and can crush grain to order, so there's nothing stopping you from starting with a single small batch before investing in anything else.

Pot size depends on batch size. As a rough guide:

A standard pasta pot (8–12L) will handle a small experimental batch of around 4–5L
A 15–20L pot works for batches of around 8–10L
For a full 19–20L batch you'll want a 35–40L pot — these are large and purpose-built for brewing

Essential

A pot (kettle) — size depends on your batch size; see above. You need enough room for the grain, the full water volume, and boil-off.
A BIAB bag — fine mesh, purpose-built for all-grain brewing, sized to fit your pot. The bag holds all the grain and acts as a natural filter when lifted.
A heat source — for small batches, your regular stove is fine. For larger volumes (15L+), a gas burner gives you more heat output and faster boil times.
A thermometer — essential for hitting and holding mash temperature. A digital probe is more accurate than a stick-on or float thermometer.
A hydrometer — to check pre-boil and post-fermentation gravity. This tells you whether the mash did its job.
Standard fermentation gear — fermenter, airlock, yeast.

Useful additions

An insulated vessel — an insulated drink cooler (the kind most households already own) works well for maintaining mash temperature. You can sit your pot inside it during the mash to hold heat without wrapping it in towels or a sleeping bag.
A pulley or bag holder — for larger grain bills, suspending the bag above the pot to drain adds to your yield and saves effort. Not necessary for small batches.
A grain mill — only worth buying if you want to mill your own grain. AHB offers a crushing service and crushes to order, so the grain in your kit is always fresh.

How do you brew using the BIAB method?

Step 1 — Weigh and prepare your grain

AHB all-grain recipe kits are crushed to order at the time of purchase, so your grain arrives ready to use. If you're building your own recipe from individual grains, AHB can crush these for you too. Weigh your grain accurately: 100g variance across 5kg of grain will shift your original gravity noticeably.

Step 2 — Heat your strike water

Fill the pot with your full batch volume — for a 19L batch this is typically 25–28L, accounting for boil-off and grain absorption. Heat to strike temperature (the temperature you heat the water to before adding grain — set slightly higher than your target mash temperature to account for the temperature drop when grain goes in). For a target mash of 66°C, strike around 69–70°C.

Step 3 — Mash

Lower the BIAB bag into the pot, add your grain, and stir thoroughly to break up any clumps. Check the temperature and adjust if needed. Hold at 65–67°C for 60 minutes.

Most Australian ale recipes target 66°C. Lower temperatures (63–64°C) produce a drier, more fermentable wort with higher ABV. Higher temperatures (68–69°C) produce a fuller-bodied, sweeter result. Start in the middle and adjust from there once you've got a few batches under your belt.

To hold temperature without constant heating, sit the pot inside an insulated drink cooler or wrap it in a towel. In an Australian summer, ambient warmth often keeps the mash stable without any insulation at all.

Step 4 — Lift and drain the bag

Lift the bag slowly and let it drain back into the pot for 5–10 minutes. Gentle pressing is fine. Don't squeeze hard — this can release tannins from the husks and cause astringency in the finished beer. For larger grain bills, a pulley or bag stand makes this easier.

A 5kg grain bill in 25L of water will typically give you a pre-boil gravity of around 1.040–1.050 for a standard ale.

Step 5 — Boil

Bring to a rolling boil and add hops per your recipe. A 60-minute boil is standard. Whirlfloc tablets added in the final 10–15 minutes improve clarity — these are included in AHB all-grain recipe kits.

Step 6 — Chill and pitch

Chill the wort to pitching temperature (18–22°C for ales) using an immersion chiller, ice bath, or by leaving it to cool overnight (see the no-chill section below). Transfer to your fermenter, pitch yeast, and ferment as normal.

When you lift the bag after the mash and see the colour of the wort — somewhere between gold and deep mahogany depending on your grain bill — you'll understand what draws people to this. It smells like a brewery. That's because it is one.

How do Australian conditions affect BIAB brewing?

Summer heat and chilling your wort

Australian summers create a practical problem for chilling wort quickly. Immersion chillers lose effectiveness when tap water approaches 25–30°C — not uncommon in inland areas or during a Melbourne or Adelaide heatwave.

One option used by some Australian home brewers is the no-chill method: instead of chilling immediately, you transfer the boiling wort into a food-safe HDPE cube (available from Bunnings and similar stores), seal it, and leave it to cool overnight. The hot wort self-sanitises the cube. You pitch yeast the next morning once the wort has dropped to pitching temperature. It's a practical solution in summer when chilling quickly isn't feasible.

No-chill does require adjusting hop additions slightly for the extended contact time. The BIAB community has established conversion tables for this, and it's worth looking them up if you plan to use the method.

Other options include chilling with an ice bath, brewing in the cooler months, or brewing smaller batches that chill faster.

Maintaining mash temperature in winter

In cold conditions — a Tasmanian or Victorian winter — maintaining mash temperature for 60 minutes without insulation is harder than you'd expect. Sitting the pot inside an insulated drink cooler works well for most situations. Wrapping in a towel or sleeping bag is also effective. For very cold days (below 10°C ambient), a small amount of supplementary heat mid-mash keeps the temperature stable.

Australian grain

Malted grain is produced by a maltings, not a brewery. AHB primarily stocks Joe White malt, which is one of Australia's most widely used base malts, alongside a range of English and European specialty malts for colour, body, and flavour. We crush grain to order so it's always fresh when it reaches you.

BIAB vs all-in-one systems: where should you start?

The honest recommendation: Start with BIAB. Learn what you need. Then step up if you want to.

All-in-one systems like the Grainfather have a built-in element, pump, and recirculation. They're more consistent, require less manual attention, and produce very clean wort. They also cost significantly more — a Grainfather G30 is upward of $1,200.

Most brewers who go straight to an all-in-one system spend the first 10 batches learning things they could have learned for the cost of a bag and a few ingredient kits. By the time you've done 15–20 BIAB brews, you know exactly what you want from a system: whether temperature consistency is your main frustration, or yield, or setup time. That context makes the equipment decision much clearer.

BIAB is the right starting point if:	An all-in-one system makes sense when:
You want to try all-grain before committing serious money	You're brewing regularly and want a contained, consistent setup
You already have a large pot and fermentation gear	You want precise mash temperature without manual intervention
You want to brew in small batches to experiment	You're ready to commit to larger batches on an ongoing basis
Budget is a priority right now	Reduced setup and cleanup time is worth the investment

AHB stocks Grainfather systems. When you're ready to step up, we can talk through which system suits your setup and batch size.

Frequently Asked Questions

What is BIAB brewing?

BIAB (Brew in a Bag) is a single-vessel all-grain brewing method. Malted grain is mashed in a fine mesh bag inside a pot, then removed before the boil. It produces excellent beer — as does a well-executed extract or kit brew. The distinction is not quality; it's the process and the relationship you have with it.

What does a BIAB setup cost in Australia?

If you already have a large pot and basic fermentation gear, the main cost is the BIAB bag (inexpensive) and your ingredients. For a small batch in a pasta pot, the barrier to entry is very low. If you're setting up for larger batches from scratch — pot, burner, fermentation gear — costs will vary considerably depending on what you already own. The ingredient cost for an all-grain recipe kit is roughly $60–90 depending on the style and batch size.

What size pot do I need for BIAB?

It depends on your batch size. A large pasta pot (8–12L) is enough for a small experimental batch of 4–5L. For 10L batches, you want around 15–20L of pot capacity. For a full 19–20L batch, a 35–40L pot is recommended — these are purpose-built brewing pots and a significant piece of equipment.

What temperature should I mash at for BIAB?

Most Australian ales mash at 65–67°C for 60 minutes. This produces a balanced wort with good fermentability and body. Lower temperatures (63–64°C) produce a drier, higher-ABV result; higher temperatures (68–69°C) produce a fuller, sweeter beer.

Can I do no-chill brewing with BIAB?

Yes. Transfer boiling wort into a sealed food-safe HDPE cube, let it cool overnight, and pitch yeast the next morning. These cubes are available from Bunnings and similar stores. It's a practical option in Australian summer when tap water is too warm to chill wort quickly, though it does require adjusting hop additions slightly.

Is BIAB the same quality as traditional all-grain brewing?

In practice, yes. Efficiency is typically slightly lower with BIAB — around 70–75% vs 75–80% for three-vessel systems — but this is accounted for in recipe design and has no impact on finished beer quality. Many brewers who've used both prefer BIAB for smaller batches.

What grains can I use in BIAB?

Any malted grain: Joe White base malt, crystal malts, roasted malts, wheat, oats, rye, and a range of English and European specialty malts. AHB stocks all-grain recipe kits for those who want a ready-made grain bill, and individual grains for those building their own recipes. We crush to order so your grain is always fresh.

Do I need a grain mill for BIAB?

No. AHB offers a crushing service and all-grain recipe kits are crushed at the time of purchase. A grain mill is only worth buying if you want to mill your own grain at home — useful if you're buying base malt in bulk or want full control over your crush.

I enjoy kit brewing. Is there a reason to try BIAB?

Not unless the process itself interests you. If you're producing beer you're happy with and enjoying the hobby, that's the point. BIAB adds time, equipment, and complexity. What it offers in return is a different kind of engagement: building a recipe from scratch, working with malted grain directly, and understanding every decision that shaped the beer.

Some kit and extract brewers experiment with BIAB occasionally just for variety, or incorporate grain steeping and mini-mashes into their existing process without committing to a full BIAB setup. Both approaches are legitimate. There's no hierarchy here.

You might also find these useful
Home Brewing for Beginners: Your Complete Guide — a solid overview of the full range of brewing methods and where each fits
Fresh Wort Kits — ferment actual brewery wort at home, no mash required. Outstanding results with minimal equipment.
All-Grain Recipe Kits — freshly crushed malted grain, Whirlfloc tablets, and instructions, ready to brew