IMS Big Bang Espresso Basket Review: Fit and Dialing In

A research-based review of the IMS Big Bang line, built from IMS Filtri spec sheets, the IMS filter code guide, and published retailer specifications. We did not bench-test these baskets.

Quick Answer

The IMS Big Bang is a ridgeless, flat-bottomed precision basket with 0.30 mm holes spaced 1.5 mm apart at the center and progressively wider toward the edge. The 58mm version (B70) has 585 holes and comes in four heights covering roughly 14 g to 26 g. The 54mm version (B62.5) fits Breville/Sage portafilters and covers roughly 12 g to 23 g. Pick the height whose IMS dose range matches your dose and roast, then dial in grind size as usual.

Comparing brands rather than one basket? The IMS vs VST vs Pullman precision basket comparison covers the broader choice. This page covers the IMS Big Bang line only.

What the IMS Big Bang Basket Is

The IMS Big Bang is a precision filter basket line from IMS Filtri, an Italian basket maker. The defining feature of the IMS Big Bang basket is its perforation: according to the IMS Big Bang line page, the distance between holes starts at 1.5 mm in the center and gradually increases toward the edge.

IMS states the Big Bang pattern is meant to counter side channeling and produce a more balanced extraction. IMS product pages describe the goal as increasing flow toward the edge (IMS B62.5 Big Bang). Water tends to find the path of least resistance along the basket wall, a problem covered in the espresso channeling guide.

IMS Big Bang baskets are cylindrical, flat-bottomed, and ridgeless, with electropolished surfaces and holes that are relaminated and recalibrated after perforation, per the IMS Big Bang overview.

IMS Big Bang Published Specifications

IMS publishes the IMS Big Bang basket specs per border size. The figures below come from the IMS product pages for the B70 (58mm), B62.5 (54mm), and B65 (53mm tamper) Big Bang baskets.

IMS Big Bang spec	B70 (58mm)	B62.5 (54mm)	B65
Border diameter	70 mm	62.5 mm	65 mm
Internal body	60 mm	54 mm	54 mm
Tamper	58/58.4 mm	53/53.4 mm	53 mm
Holes	585	497	497
Perforated area	49 mm	44 mm	—
Hole diameter	0.30 mm	0.30 mm	0.30 mm, conical
Heights listed	21.5 / 23.5 / 25.5 / 27.5 mm	21.5 / 23.5 / 25.5 / 27.5 mm	27 mm

IMS also lists a B66 Big Bang basket and machine-specific variants (B65 9 Barista, B65 Aram, B70 Superkop) on the Big Bang line page. Check the IMS product page for those exact codes before buying.

IMS Big Bang Fit by Portafilter Size

IMS Big Bang fit depends on the border code, the first part of every IMS filter code. The IMS filter code guide says the internal diameter of the filter body determines tamper compatibility, and the border diameter must match the machine's portafilter.

58mm portafilters (La Marzocco, Rocket, Rancilio, ECM and many E61 machines): the IMS Big Bang B70 basket, used with a 58/58.4 mm tamper. IMS lists 50+ compatible brands on the B70 Big Bang page.
58mm Gaggia, La Cimbali, and Carimali: the IMS filter guide assigns these machines the B68 border, not B70. IMS does not list a B68 in the Big Bang line, so confirm availability before ordering.
54mm Breville/Sage and Solis portafilters: the IMS Big Bang B62.5 basket with a 53/53.4 mm tamper (IMS B62.5).
La Spaziale, Aram, Astoria, and Wega: the IMS Big Bang B65 basket with a 53 mm tamper (IMS B65).

The IMS Big Bang basket is ridgeless, so it relies on the portafilter's spring clip differently than a ridged stock basket. For help identifying your portafilter size, see espresso portafilter sizes explained. To find the exact code for your portafilter and dose, including the B65 size, use the IMS Big Bang basket size and portafilter fit chart. If you are deciding between hole patterns within the IMS range, see how the Big Bang stacks up in our IMS Big Bang vs IMS Competition basket comparison.

IMS Big Bang Heights and Dose Ranges by Roast

IMS publishes IMS Big Bang dose ranges for each basket height and roast level. IMS notes these ranges were set with a dark 80/20 blend, a medium 100% Arabica Brazil, and a light Ethiopian single origin (IMS B62.5 23.5 mm). Lighter roasts take a slightly higher dose in the same IMS Big Bang basket.

IMS Big Bang B70 (58mm) dose ranges

Code	Height	Dark	Medium	Light
B702TFH21.5BB	21.5 mm	14–16 g	15–17 g	16–18 g
B702TFH23.5BB	23.5 mm	17–19 g	18–20 g	19–21 g
B702TFH25.5BB	25.5 mm	20–22.5 g	21–23 g	21.5–24 g
B702TFH27.5BB	27.5 mm	22–24.5 g	23–25 g	24.5–26 g

Source: IMS B702TFH27.5BB page and related-model table.

IMS Big Bang B62.5 (54mm Breville/Sage) dose ranges

Code	Height	Dark	Medium	Light
B62.52TFH21.5BB	21.5 mm	12–14.5 g	13–15 g	14–16 g
B62.52TFH23.5BB	23.5 mm	14–17 g	15.5–18 g	17.5–20 g
B62.52TFH25.5BB	25.5 mm	17–19.5 g	18–21 g	18–20.5 g
B62.52TFH27.5BB	27.5 mm	18–22 g	18.5–22.5 g	20–23 g

Source: IMS B62.52TFH23.5BB page and related-model table. Retailers such as Whole Latte Love sell the 58mm 23.5 mm model as a 17–21 g basket, matching the IMS dark-to-light span.

Dialing In an IMS Big Bang Basket

Dialing in an IMS Big Bang basket starts before the grinder: choose the basket height whose IMS range contains your dose. A dose outside the IMS Big Bang range for that height changes the space above the puck, which is why IMS sells four heights instead of one.

Match dose to the IMS Big Bang table. Weigh the dose and pick it from the dark, medium, or light column for your basket height.
Keep the old recipe as the starting point. Hold ratio and dose constant after switching to the IMS Big Bang basket, then adjust only grind size.
Adjust grind by shot time and taste. A fast, sour IMS Big Bang shot calls for a finer grind; a slow, bitter shot calls for coarser. The full method is in how to dial in espresso.
Use a tamper that matches the IMS Big Bang body. A 58/58.4 mm tamper for B70, and 53/53.4 mm for B62.5 or B65, per IMS.
Consider a matching puck screen. IMS makes Big Bang-perforated puck diffusers (DS58.5BB, DS53.5BB, DS51BB) listed on the Big Bang line page. A screen also takes headspace, so recheck dose. See the puck screen guide.

Change one variable at a time and log each IMS Big Bang shot, so a good result is repeatable. If shots start running fast after the swap, follow the ordered fix path in IMS Big Bang shots running fast: what to adjust.

IMS Big Bang Strengths and Limits

IMS Big Bang strengths

Documented design goal: the IMS Big Bang hole spacing targets side channeling.
Published dose ranges by height and roast, which few basket makers provide.
Available for both 58mm machines and 54mm Breville/Sage portafilters.
Electropolished, ridgeless, flat-bottomed build.

IMS Big Bang limits

Four heights per size means picking the wrong IMS Big Bang height is easy; buy by dose.
Gaggia and Cimbali B68 machines have no Big Bang border listed by IMS.
A precision basket does not replace a capable grinder or consistent puck prep.
No IMS Big Bang flavor claim is independently measured in the sources here.

IMS Big Bang Basket FAQ

Is the IMS Big Bang basket worth it?

The IMS Big Bang basket is worth considering for a home barista with a 58mm or 54mm portafilter who already weighs doses and wants a precision basket built around even edge flow. IMS designed the Big Bang hole spacing to widen from 1.5 mm at the center toward the edge to counter side channeling. It will not fix inconsistent grinding or puck prep.

Does the IMS Big Bang basket fit a Breville portafilter?

IMS lists the Big Bang B62.5 basket, with a 54 mm internal body and a 53/53.4 mm tamper, as compatible with Breville/Sage and Solis machines. The 58mm Big Bang B70 basket does not fit a 54mm Breville portafilter.

What size IMS Big Bang basket should I buy for an 18 g dose?

For an 18 g dose in a 58mm portafilter, IMS lists the 23.5 mm Big Bang B70 basket at 18–20 g for medium roast and 17–19 g for dark roast. In a 54mm Breville portafilter, the 23.5 mm B62.5 Big Bang basket covers 15.5–18 g of medium roast.

How many holes does the IMS Big Bang basket have?

The 58mm IMS Big Bang B70 basket has 585 holes of 0.30 mm across a 49 mm perforated area. The 54mm IMS Big Bang B62.5 basket has 497 holes across a 44 mm perforated area.

Is the IMS Big Bang basket ridgeless?

Yes. IMS lists every Big Bang filter basket as ridgeless, cylindrical, and flat-bottomed, so the IMS Big Bang basket may sit looser in portafilters that rely on a basket ridge and retaining spring.