- The best BIAB bag fits your kettle's diameter, has a strap or drawstring that survives a wet grain lift, and fine enough mesh to hold back husks.
- The Brew Bag by Wilser is the sturdy pick: sewn-in 1-inch straps, X-stitched joints and a 200 lb lift-and-hold rating per the maker.
- Budget mesh bags (CONIE, Boao, JJUNW) work for small batches; check the bag diameter against your kettle.
- A hop spider keeps pellet debris out of the fermenter; the Mangrove Jack's and Homebrewers Outpost AG460 use stainless mesh and hang from the rim.
The best BIAB bag and hop spider let you brew all-grain in a single kettle: mash the grain in a bag, lift it out, boil, and keep hop debris in a basket instead of the fermenter. We compared ten picks from nine brands, six bags and four hop filters, using the dimensions, mesh, materials and load figures each listing gives. Where a figure is missing, we say not listed.
BIAB (brew in a bag) is the simplest step into all-grain. It suits a large kettle on an outdoor burner, an induction plate, or an electric kettle. For kettle sizes, see our brew kettle picks.
Our picks
The Brew Bag for 50–60 Qt Kettles
Wilser (The Brew Bag)
- Volume
- Fits 50 and 60 qt kettles
- Material
- Mesh with 1 in. poly straps
- Type
- BIAB bag
The Brew Bag sized for 50 and 60 qt kettles uses 1-inch poly straps sewn into the bag to carry the grain weight, with X-stitching at every strap crossing. The maker rates it for a 200 lb lift-and-hold, says it holds over 100 lb of grain, and describes it as food-safe polyester. Turn it inside out to hand wash.
Best for: 5–10 gallon BIAB in 12–15 gallon kettles
Skip if: Your kettle is 8 gallons or smaller
- Sewn-in lifting straps
- 200 lb lift rating (maker)
- Smooth interior seams for cleaning
- Sized for 50–60 qt only
- Mesh size not listed
The Brew Bag Pro-Series for 10 Gal Coolers and Larger Kettles
Wilser (The Brew Bag)
- Volume
- Fits 10 gal round coolers and larger kettles
- Material
- Mesh with 1 in. poly straps
- Type
- BIAB bag
The Pro-Series version of The Brew Bag fits 10-gallon round Igloo and Rubbermaid coolers and larger kettles, with the same sewn-in straps, X-stitched joints and 200 lb rating per the maker. In a cooler it replaces a false bottom and filters the runoff.
Best for: Cooler mash tuns without a false bottom
Skip if: You only brew in a 5–8 gallon kettle
- Fits 10 gal round coolers
- No false bottom needed
- Reinforced straps
- Too large for small kettles
- Mesh size not listed
JJUNW Extra Large Brew Bags, 26 x 22 in., 3-Pack
JJUNW
- Volume
- 26 × 22 in.
- Material
- Fine mesh
- Type
- BIAB bag
JJUNW's three 26 × 22 inch fine-mesh drawstring bags fit kettles up to 17 inches across and hold up to 20 lb of grain, per the listing, with double-reinforced stitching.
Best for: 5-gallon BIAB with spare bags on hand
Skip if: Your grain bills go over 20 lb
- Three bags
- Fits up to 17 in. kettles
- 20 lb grain rating (listing)
- Drawstring, no lifting straps
- Mesh size not listed
CONIE Nylon Straining Brew Bag, 18 x 24 in.
CONIE
- Volume
- 18 in. diameter × 24 in. high
- Material
- Food-grade nylon, 75 micron
- Type
- BIAB bag
CONIE's straining bag is BPA-free food-grade nylon, 75 micron, 18 inches in diameter and 24 inches high, with a drawstring. Fine mesh holds back more grain flour, which helps clarity in small BIAB batches.
Best for: 2–3 gallon BIAB and straining fruit
Skip if: You need straps for a heavy 5-gallon grain lift
- 75 micron nylon
- 18 in. diameter
- Reusable
- Drawstring only
- Fine mesh drains slower
Boao Reusable Fine Mesh Brew Bags, 4-Pack
Boao
- Volume
- 16 × 18 in. and 26 × 22 in.
- Material
- Polyester mesh
- Type
- BIAB bag
Boao's four polyester mesh bags come in two sizes, about 22 × 26 inches and 16 × 18 inches, for buckets or pots up to about 17 or 11 inches across. Each has a drawstring.
Best for: Brewers who also strain fruit for cider or wine
Skip if: You want one heavy-duty bag
- Four bags, two sizes
- Drawstrings
- Washable
- No load figure listed
- Polyester mesh size not listed
Mangrove Jack’s Hop Spider
Mangrove Jack's
- Volume
- 5.9 in. diameter × 11.8 in.
- Material
- 800 micron 304 stainless mesh
- Type
- Hop spider
Mangrove Jack's hop spider is an 800-micron 304 stainless mesh tube, 5.9 inches in diameter and 11.8 inches long, with a stainless support band and a single hook to hang it on the kettle.
Best for: Keeping pellet hop debris out of a pump, chiller or fermenter
Skip if: Your kettle rim is too thick for a single hook
- 800 micron 304 stainless
- Rigid support band
- Hangs from the rim
- Single hook can tip if bumped
- 11.8 in. long, check depth
Homebrewers Outpost AG460 Hop Spider
Homebrewers Outpost
- Volume
- 13.75 in. tall × 5.9 in. opening; up to 10 oz pellets
- Material
- Stainless steel mesh
- Type
- Hop spider
Homebrewers Outpost's AG460 is a stainless mesh hop spider 13.75 inches tall with a 5.9-inch opening that hangs from the kettle side and holds up to 10 oz of pellet hops, per the listing.
Best for: IPAs with large hop additions
Skip if: Your kettle is shallow
- Holds up to 10 oz pellets
- Tall 13.75 in. basket
- Hangs from the side
- Mesh size not listed
- Tall basket needs deep wort
Hicarer 4 x 10 in. Stainless Hop Spider, 2-Pack
Hicarer
- Volume
- 4 × 10 in.
- Material
- 304 stainless steel
- Type
- Hop spider
Hicarer's two-pack of 304 stainless hop spiders measures 4 × 10 inches each, with built-in hooks that rest on a kettle or fermenting bucket rim.
Best for: Boil hops in one and dry hop in the other
Skip if: You want a wide 6-inch basket for big additions
- Two spiders
- 304 stainless
- Built-in hooks
- 4 in. diameter is narrow
- Mesh size not listed
Strange Brew Hop Spider
Strange Brew
- Volume
- 3 3/4 in. opening, 9 in. arms
- Material
- Stainless
- Type
- Hop spider
Strange Brew's hop spider is a stainless frame with a 3 3/4-inch opening and 9-inch arms that rests across the kettle and holds a hop bag. It is basic, light and easy to store.
Best for: Extract brewers who already use hop bags
Skip if: You want a rigid mesh basket
- Simple frame
- 9 in. arms span the kettle
- Uses any hop bag
- Bag sold separately
- Small opening
Fdit 6 in. Stainless Hop Filter, 1/2 in. NPT
Fdit
- Volume
- 6 in.
- Material
- 304 stainless mesh, 1/2 in. NPT
- Type
- Kettle hop filter
Fdit's 6-inch 304 stainless mesh filter threads onto a 1/2-inch NPT fitting inside the kettle or mash tun, so whole hops and pellet debris stay behind when you drain through the valve.
Best for: Kettles with a 1/2 in. NPT valve and a pump or plate chiller
Skip if: Your kettle has no valve
- Threads onto 1/2 in. NPT
- 304 stainless
- Free-floating hops stay in the kettle
- Pellet sludge can still clog it
- Needs a threaded fitting
What size BIAB bag do you need?
A BIAB bag should be wider than the kettle so it drapes over the rim, and deep enough to reach the bottom with room for the grain. Measure the kettle's inside diameter and height first. The table lists what each listing gives.
BIAB bags and hop filters: listed dimensions and materials
| Pick | Type | Size | Material or mesh | Lift or load |
|---|---|---|---|---|
| The Brew Bag, 50–60 qt | BIAB bag | Fits 50 and 60 qt kettles | Polyester mesh, 1 in. poly straps | 200 lb lift (maker) |
| The Brew Bag Pro, 10 gal cooler | BIAB bag | 10 gal round coolers, larger kettles | Polyester mesh, 1 in. poly straps | 200 lb lift (maker) |
| JJUNW 3-pack | BIAB bag | 26 × 22 in., kettles to 17 in. | Fine mesh | 20 lb grain (listing) |
| CONIE | BIAB bag | 18 in. dia × 24 in. | Nylon, 75 micron | Not listed |
| Boao 4-pack | Straining bag | 22 × 26 and 16 × 18 in. | Polyester mesh | Not listed |
| Mangrove Jack's | Hop spider | 5.9 in. dia × 11.8 in. | 304 stainless, 800 micron | Not listed |
| Homebrewers Outpost AG460 | Hop spider | 13.75 in. tall, 5.9 in. opening | Stainless mesh | Up to 10 oz pellets |
| Hicarer 2-pack | Hop spider | 4 × 10 in. | 304 stainless | Not listed |
| Strange Brew | Spider frame | 3 3/4 in. opening, 9 in. arms | Stainless | Not listed |
| Fdit | Valve filter | 6 in., 1/2 in. NPT | 304 stainless mesh | Not listed |
Source: Product listings, November 2026
Hop spiders compared by size
A hop spider has to sit deep enough in the wort for the hops to work, but not so deep that it touches a heating element or blocks a chiller. Compare the basket length with your wort depth.
Hop basket length (inches)
Listed length or height; the Strange Brew frame holds a separate bag
Mesh size is a trade-off. Fine mesh holds back more debris but lets less wort through, which can slow hop extraction; coarser mesh flows freely but passes some pellet sludge. The Mangrove Jack's 800-micron rating is the only listed mesh among the spiders here.
IBU calculator (Tinseth)Hop spiders can lower utilization slightly; check your IBU estimate and adjust if your beers taste less bitter than planned.How to brew in a bag: the short version
- Heat the full water volume
BIAB uses all the water at once, so the mash is thin. Heat to strike temperature; the strike water calculator handles the math.
- Line the kettle and add grain
Drape the bag over the rim, clip it if needed, and stir the grain in to break up dough balls.
- Mash and hold temperature
Hold for about 60 minutes, insulating the kettle with a blanket if you heat with propane, and with the burner off.
- Lift and drain
Wet grain is heavy. Lift slowly with the straps, or use a pulley or a rack across the kettle, and let it drain. Wear heat-resistant gloves.
- Boil with a hop spider
Hang the spider before the first hop addition and lift it out at flame-out, before chilling.
Safety for BIAB on a burner
BIAB in a large kettle usually means an outdoor propane burner, and that burner belongs in open air, away from the house, never in a garage. Turn the flame off before lifting the bag so the mesh can't touch the burner, and never lift a heavy wet bag over a lit flame. Electric kettles and all-in-ones avoid the open flame; run them on a GFCI-protected circuit.
BIAB and hop spider mistakes to avoid
- Letting the bag touch a heating element. Use a false bottom, a basket or keep the heat off while the bag is in.
- Buying a bag smaller than the kettle. It slides into the wort; measure the diameter.
- Squeezing over a lit burner. Turn off the heat first, and protect your hands.
- Overpacking a hop spider. Hops swell; leave room for wort to circulate.
- Forgetting to clean the mesh. Rinse, turn bags inside out, and dry fully before storage.
Which bag or spider should you buy?
- 5–10 gallon BIAB in a 12–15 gallon kettle: The Brew Bag for 50–60 qt.
- Cooler mash tun without a false bottom: The Brew Bag Pro-Series.
- Budget 5-gallon BIAB: JJUNW 3-pack.
- Small batches, fine mesh: CONIE.
- Beer plus fruit straining: Boao 4-pack.
- One sturdy hop spider: Mangrove Jack's; Homebrewers Outpost AG460 for big IPA additions.
- Boil and dry hop: Hicarer 2-pack.
- Kettle with a valve and a pump: Fdit valve-side filter.
For steeping specialty grains in extract recipes, small cotton bags do the job.
Regency Wraps Cotton Hop and Grain Bags, 14 in., 10-Pack
- Volume
- 14 in. bags
- Material
- Cotton
- Type
- Steeping bags
Best for Steeping grains in extract brewing
Ready to replace the bag and burner with one appliance? Our all-in-one systems use a grain basket instead. After the boil, an immersion chiller is the simplest way to cool a BIAB kettle.
For most BIAB brewers, The Brew Bag sized to the kettle is the best BIAB bag here: sewn-in straps and a 200 lb rating per the maker make the wet-grain lift safer. Budget bags like JJUNW work for 5-gallon batches. Pair it with a Mangrove Jack's or AG460 hop spider to keep debris out of the fermenter, and keep any propane burner outdoors.
Before you buy, read how to brew all-grain: BIAB and all-in-one. For a closer look, see BIAB vs three-vessel brewing.
We compared bag and basket dimensions, mesh and materials, lift and capacity figures, and fit from current listings, and checked the BIAB process against Palmer's How to Brew and the AHA. Load figures are maker claims. We did not brew with these products, and we don't show scores, star ratings or prices.