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Extraction · Single-serve

Single-serve beyond capsules

The other ways to brew one cup from a pre-measured dose – paper espresso pods, soft pads for pad machines, drip bags hung on the cup and coffee bags steeped like tea – how each is built and what the few studies measured.

Across the chain: Equipment

Source-checkedby Coffearium verification pass· Last source-checked 27 Oct 2026· Prepared with AI assistance· 15 sources (13 tier A)· 1 contested· Updated 27 Oct 2026· Literature last searched 27 Oct 2026
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Contents
  • An E.S.E. (Easy Serving Espresso) pod is ground coffee pressed between two layers of filter paper, about 7 g by the consortium’s account; one weighed 44 mm pod held 7.23 g.2,1
  • Soft pads are filter-paper pouches brewed in a holder; one patent describes a pouch about 74 mm wide, another gives 0.7 bar as an example water supply pressure.5,6
  • Drip bags hook over the cup rim and are filled by pouring; coffee bags are steeped in the cup like tea bags.8,9
  • In 30 Dutch pad samples, pad coffee held 0.76 mg/L of the diterpene cafestol, as much as filtered coffee in that study; unfiltered coffee held 72.5 mg/L.7
  • A 2021 carbon footprint study found 18.5 g CO₂e for a 40 mL pod cup, against 10 g for a capsule cup; packaging was the largest share.1

One cup from a ready dose#

Single-serve formats hold one measured dose of ground coffee, ready to brew. Capsules are the best-known kind and have their own entry. This entry covers four formats that use paper or fabric filters instead of a sealed capsule.2,5,8,9

  • A paper espresso pod is a flat disc of pressed coffee sealed in filter paper. It is brewed in an espresso machine.2
  • A soft pad is a larger, flexible paper pouch. It is brewed in a pad machine, with hot water fed under pressure.5,6
  • A drip bag is a small filter bag that hangs on the rim of the cup. Hot water is poured into it.8
  • A coffee bag is steeped in the cup like a tea bag.9

Soluble coffee, which dissolves without any filter, is a separate topic.

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Four single-serve formats

  1. Sealed paper rim. Two layers of filter paper sealed around the pod.2,4
  2. Pressed coffee. About 7 g in an E.S.E. pod; the pods in one study were 44 mm across.2,1
  3. Soft pad. Filter-paper pouch about 74 mm across.5
  4. Pad holder. Holds the pad under the water inlet.5,6
  5. Outflow opening. In the bottom of the holder.6
  6. Filter bag. Opened along a perforated line.8
  7. Hook parts. Hold the bag on the cup rim.8
  8. Coffee bag. Sealed paper bag steeped in hot water.9,10
How the four formats are built, from their patents and the E.S.E. Consortium. Pod and pad drawn in their stated proportions; cups, bags and holder are schematic. Point at a number or a line of the legend to highlight the part. Schematic, not to scale.

Paper pods for espresso#

The best-known paper pod follows the E.S.E. standard. E.S.E. stands for Easy Serving Espresso. According to the consortium that maintains it, each pod holds about 7 g of coffee pressed between two layers of filter paper.2 One study used such pods, 44 mm across, and weighed 7.23 g of coffee in 0.180 g of paper.1

The pod goes into the machine’s filter holder in place of loose grounds. The consortium specifies a brewing chamber shaped to fit the pod.2 A coffee science textbook describes pod and capsule espresso as systems in which almost every parameter is fixed in advance.13

Pods are older than the standard. A 1980 patent application for a pod espresso machine calls such pods already known.3

Soft pads and pad machines#

A soft pad is a flat pouch of filter paper filled with ground coffee.5 It is wider and looser than an espresso pod. A 1997 patent application describes a pouch about 74 mm across.5

The pad lies in a holder in the machine. Hot water is pressed onto it from above and runs out through an opening in the bottom of the holder.5,6 A later patent gives 0.7 bar as an example pressure of the hot water fed to the holder’s inlet.6

Drip bags and coffee bags#

A drip bag turns a cup into a small pour-over brewer. The filter bag holds a dose of ground coffee. It is torn open along a perforated line, and hook parts, punched from a thin plate such as paper or plastic sheet, hold it on the rim of the cup.8 Hot water is poured into the open bag and drains through it into the cup.8

A coffee bag works by immersion. A porous paper bag with a measured dose is held in a cup of hot water.9 A 1969 patent application tells the user to dip it up and down for 50 or 60 seconds.9 That is the inventor’s instruction, not a measured brewing time.

Pods of injection-moulded polypropylene with a filter inside also exist.12 They work like capsules and are covered in Coffee capsules.

What the E.S.E. standard specifies#

The E.S.E. standard covers both the pods and the machines. The consortium’s own summary describes pre-packed doses of ground coffee, pressed and sealed between two layers of filter paper.2 It gives about 7 g of coffee and 0.2 g of paper per serving.2 A 2021 study measured 7.23 ± 0.02 g of coffee and 0.180 ± 0.002 g of paper in a 44 mm pod.1

For machines, the summary names an extraction chamber of a specially designed shape. It also names water temperature and pressure as parameters that are checked before the trademark is granted.2 The summary gives no figures for either. The full specification was not consulted for this entry. Its dimensions, tolerances, temperature and pressure limits are therefore not reported here.

In the 2021 study, each pod was wrapped in a laminated pouch of polyethylene, aluminium and PET (polyethylene terephthalate) weighing 1.51 g.1 The paper filter itself is thus a small part of the packaging of each dose.

How the formats are built#

Patents show how the formats are built and when each design was filed. They do not show how well any of them brews. The patents below were consulted for this entry; none is the first of its kind.

Year (filed or priority) Document Format What it describes
1969 US 3,607,3029 Coffee bag Porous paper envelope with a measured dose, dipped in a cup of very hot water for 50 or 60 s
1980 EP 0 041 657 B13 Paper pod Espresso machine for pods; the pods, “known from the prior art”, hold coffee that may be compressed in a cover of filter paper or cloth; about 40 cm³ of water for an espresso, about 120 cm³ for a weak coffee from the same pod
1986 US 4,746,51910 Coffee bag Two sheets of water-permeable paper heat-sealed around a portion of very fine ground coffee
1993 US 5,776,5274 Paper pod Filter-paper tablet with a sealing edge stiffened by cardboard rings, clamped in the brewing chamber
1997 EP 0 904 717 B15 Soft pad Pouch about 74 mm across with a coffee bed about 61 mm across, in a holder with grooves in its bottom; patent revoked on appeal in 200614
2004 US 9,714,136 B26 Soft pad Flexible top and bottom sheets sealed at the edge; holder with outflow opening; 0.7 bar given as an example pressure of the water fed to the inlet
2012 US 10,246,252 B28 Drip bag Filter bag with hook parts for the cup rim and a perforated opening line; filter materials named include papers and woven or nonwoven fabrics

The 2012 drip-bag patent cites earlier Japanese patent literature on drip bags with paper-plate hook members.8 It describes simple drip bags as already on the market.8

Reference values#

The values below are what the consulted sources report. Several come from patents and describe designs, not measured brews.

Parameter Value Format Source
Coffee per pod ≈7 g (consortium summary); 7.23 ± 0.02 g (measured) E.S.E. pod 2,1
Paper per pod ≈0.2 g (consortium summary); 0.180 ± 0.002 g (measured) E.S.E. pod 2,1
Pod diameter 44 mm E.S.E. pod 1
Cup volume, serving time 40 mL; 30 s on average Pod machine in one LCA 1
Water per gram of coffee ≈5.5 mL/g (our calculation: 40 mL ÷ 7.23 g) Pod machine in one LCA 1
Controller set points tested 90, 100, 110 °C; measured brew temperatures significantly lower Espresso pods 11
Pouch and coffee-bed diameter ≈74 mm and ≈61 mm Soft pad (patent) 5
Water pressure at the holder inlet 0.7 bar given as an example Soft pad (patent) 6
Cafestol in the cup 0.76 mg/L (95% CI 0.69–0.82) Soft pad, 30 samples 7
Steeping time 50 or 60 s (inventor’s instruction) Coffee bag (patent) 9

The water-per-gram figure assumes that the 40 mL cup is the beverage volume and that all of it passed through the pod. The study does not report extraction yield or TDS, so the strength of the cup is not known.1

Paper filters and coffee oil#

All four formats brew through paper or fabric. A coffee science textbook states that filter paper absorbs oil very efficiently, so paper-filtered brews are low in fat.13

A 2006 Dutch study tested this for soft pads. It bought 30 samples of pads in five cities and brewed them in a pad machine.7 Pad coffee held 0.76 mg/L of cafestol, one of the two coffee diterpenes; filtered coffee held the same amount.7 Unfiltered coffee held 72.5 mg/L.7 Only the abstract was consulted.

020406080mg/LCoffee pads (pad machine)0.76 mg/L (95% CI 0.69–0.82)7 Filtered coffee0.76 mg/L (95% CI 0.63–0.88)7 Unfiltered coffee72.5 mg/L (95% CI 48.5–96.4)7
Data table
mg/LSource
Coffee pads (pad machine)0.76 mg/L (95% CI 0.69–0.82)7
Filtered coffee0.76 mg/L (95% CI 0.63–0.88)7
Unfiltered coffee72.5 mg/L (95% CI 48.5–96.4)7
Cafestol in coffee from pads, filtered coffee and unfiltered coffee, means with 95% confidence intervals in one 2006 study.7 The pad and filtered bars are barely visible at this scale.

Values for paper-filtered coffee differ between studies. In a 2025 Swedish study, home-brewed drip coffee of five brands through two kinds of paper filter held a median of about 12 mg/L of cafestol (range 4–24 mg/L).15 That is more than ten times the filtered value of the 2006 study; the two studies used different coffees, brewers and laboratories. Brew methods gives the 2025 values for other brewers. No study consulted for this entry measured diterpenes from espresso pods, drip bags or coffee bags.

Measured brewing#

Few studies have measured these formats as brewers. In a 2009 study, espresso was made from five pods at controller set points of 90, 100 and 110 °C.11 The temperatures measured during extraction were significantly lower than the set points.11 At 110 °C, solids and caffeine indicated over-extraction, according to the abstract.11

No study consulted for this entry measured extraction yield, TDS or flow from soft pads, drip bags or coffee bags. Studies of capsules exist and are covered in Coffee capsules. Their results cannot be assumed to hold for paper formats, which have no sealed body.

Packaging and environment#

A 2021 study compared the carbon footprint of a 40 mL cup from an E.S.E. pod machine, a capsule machine and an induction moka pot.1 It left out growing, roasting and grinding the coffee. The pod cup came to 18.5 g CO₂e, the capsule cup to 10 g and the moka pot cup to 8 g.1 Making the packaging was the largest share, 51.6% for the pod.1 The comparison rests on one machine of each kind.

A 2020 study assessed plastic and compostable pods of this kind, counting the packaging only.12 The entry Capsules and the environment covers such assessments, and Packaging covers the EU rules. No life cycle assessment consulted for this entry covered drip bags or coffee bags.

Open questions#

  • Extraction from paper formats. No study consulted for this entry measured extraction yield or strength for soft pads, drip bags or coffee bags. How pressing the coffee in an E.S.E. pod changes flow and extraction compared with loose grounds is also not reported in the sources consulted.
  • The E.S.E. specification in full. Its numeric limits for pods and machines were not available in the sources consulted.
  • Fabric filters. The drip-bag patent lists woven and nonwoven fabrics among possible filter materials.8 No study consulted for this entry measured what such filters retain or release into hot coffee.

Key studies#

Cibelli et al., 2021 – Moka, capsule and pod. Weighed the packaging and coffee of an E.S.E. pod and a capsule and measured the energy use of each machine. The pod cup had the highest footprint of the three methods, mostly from packaging.

Chemical Engineering Transactions 87, 373–378 · doi:10.3303/CET2187063

Boekschoten et al., 2006 – Diterpenes in pad coffee. Bought 30 samples of coffee pads in five Dutch cities and measured cafestol and kahweol in the brewed coffee. Pad coffee held as little as filtered coffee and about a hundredth of what unfiltered coffee held.

Nederlands Tijdschrift voor Geneeskunde 150(52), 2873–2875 · Wageningen University record

Albanese et al., 2009 – Espresso from pods. Brewed espresso from five pods at three set temperatures and logged the temperature during extraction. It stayed below the set point, and the highest setting gave signs of over-extraction.

Food Research International 42, 727–732 · doi:10.1016/j.foodres.2009.02.027

Contested
  • Cafestol in paper-filtered coffee: a 2006 Dutch study found 0.76 mg/L in filtered coffee and in pad coffee;7 a 2025 Swedish study found a median of about 12 mg/L (range 4–24) in home-brewed paper-filtered drip coffee.15 Coffees, brewers and laboratories differed.
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Change log

  • – 0.7 bar in the soft-pad patent narrowed to the example pressure of the hot water fed to the holder inlet. Reason: US 9,714,136 gives it as the supply pressure at the lid's water inlet, not a brewing pressure.
  • – The 44 mm pod size narrowed to the pods of one study; the E.S.E. 7 g figure attributed to the consortium. Reason: Cibelli et al. describe the pods they used; the consortium page gives no diameter.
  • – Revocation of EP 0 904 717 dated (30 August 2006) and sourced. Reason: EPO Board of Appeal decision T 0452/05 revoked the patent.
  • – Unsourced sentence on cafestol in paper-filtered coffee replaced by the 2025 Swedish values and listed as contested beside the 2006 Dutch values. Reason: Orrje et al. 2025 found a median of about 12 mg/L in paper-filtered drip coffee, far above the 0.76 mg/L of Boekschoten et al. 2006.
  • – Drip-bag hook parts and fabric filters narrowed; soft pads no longer called low-pressure. Reason: US 10,246,252 names paper or plastic sheet for the hooks and lists fabrics among possible filter materials; no source called pad brewing low-pressure.

Sources

  1. ACibelli, M.; Cimini, A.; Moresi, M. (2021). Carbon footprint of different coffee brewing methods. Chemical Engineering Transactions 87, 373–378. doi:10.3303/CET2187063 · other copiesQuoted passage: the authors’ own result; Carbon footprint (cradle to grave without coffee production, roasting and grinding) of one 40 mL cup; one pod machine, one capsule machine, one induction moka pot; Italy; masses measured..
  2. BE.S.E. Consortium The E.S.E. standard. E.S.E. Consortium (website).Quoted passage: a description; Consortium web page summarising the E.S.E. standard for pods and machines; no numbers for dimensions, temperature or pressure..
  3. AIlly, E. (proprietor ILLYCAFFE S.p.A.) (1985). Espresso coffee machine for brewing coffee from coffee pods (European Patent EP 0 041 657 B1). European Patent Office; Italian priority 10 June 1980, filed 28 May 1981, granted 16 January 1985.Quoted passage: a description; European patent specification for a pod espresso machine with two pumps (espresso about 40 cm³, weak coffee about 120 cm³ through the same pod)..
  4. ABlanc, J. P. (assignee Compagnie Méditerranéenne des Cafés SA) (1998). Package of ground coffee of the prefilled tablet type and espresso coffee machine using such a package (US Patent 5,776,527). United States Patent and Trademark Office; French priority 6 September 1993, international (PCT) filing 5 September 1994, granted 7 July 1998.Quoted passage: a description; US patent for a filter-paper coffee tablet with a stiffened sealing edge and an espresso machine that clamps it..
  5. ADijs, D. A. J. (proprietor Sara Lee/DE N.V.) (2001). Assembly for use in a coffee machine for preparing coffee, container and pouch of said assembly (European Patent EP 0 904 717 B1). European Patent Office; priority 30 September 1997, filed 30 September 1998, granted 11 July 2001 (revoked on appeal, 30 August 2006).Quoted passage: a description; European patent for a pad holder (container) with grooves in its bottom and a filter-paper pouch of ground coffee; revoked on appeal in 2006 (T 0452/05); no pressure value or dose given..
  6. AKoeling, H. C.; Brouwer, G. F. (assignee Koninklijke Douwe Egberts B.V.) (2017). Pad and assembly of a holder and such a pad (US Patent 9,714,136 B2). United States Patent and Trademark Office; priority 28 April 2004, filed 28 August 2012, granted 25 July 2017.Quoted passage: a description; US patent for a soft pad and its holder; 0.7 bar is an example pressure of the hot water fed to the lid's water inlet, not a measured brewing pressure..
  7. ABoekschoten, M. V.; van Cruchten, S. T. J.; Kosmeijer-Schuil, J. G.; Katan, M. B. (2006). Negligible amounts of cholesterol-raising diterpenes in coffee made with coffee pads in comparison with unfiltered coffee (Verwaarloosbare hoeveelheden cholesterolverhogende diterpenen in koffie bereid met koffiepads, vergeleken met ongefilterde koffie). Nederlands Tijdschrift voor Geneeskunde 150(52), 2873–2875.Quoted passage: the authors’ own result; 30 samples of coffee pads bought in three supermarkets in each of five Dutch cities, brewed in a pad machine; gas chromatography; abstract only..
  8. ASaitoh, M.; Miyawaki, A. (assignee Ohki Co., Ltd.) (2019). Drip bag (US Patent 10,246,252 B2). United States Patent and Trademark Office; Japanese priority 11 December 2012, filed 11 December 2013, granted 2 April 2019.Quoted passage: a description; US patent for a single-cup drip bag with hook parts; names earlier Japanese patents for paper-plate hooks..
  9. ABeck, R. C. (1971). Coffee bag (US Patent 3,607,302). United States Patent Office; filed 16 December 1969, granted 21 September 1971.Quoted passage: a description; US patent for a paper coffee bag dipped in a cup of hot water; steeping time is the inventor's instruction, not a measurement..
  10. A(1988). Coffee bags (US Patent 4,746,519). United States Patent and Trademark Office; filed 22 December 1986, published 24 May 1988.Quoted passage: a description; US patent for heat-sealed paper coffee bags, including a cylindrical variant, steeped in a cup of hot water..
  11. AAlbanese, D.; Di Matteo, M.; Poiana, M.; Spagna Musso, S. (2009). Espresso coffee (EC) by POD: study of thermal profile during extraction process and influence of water temperature on chemical–physical and sensorial properties. Food Research International 42, 727–732. doi:10.1016/j.foodres.2009.02.027 · other copiesQuoted passage: the authors’ own result; Espresso from five pods (arabica, robusta and three blends) at controller set points of 90, 100 and 110 °C; lab study, Italy; abstract only..
  12. AKooduvalli, K.; Vaidya, U. K.; Ozcan, S. (2020). Life Cycle Assessment of Compostable Coffee Pods: A US University Based Case Study. Scientific Reports 10, 9158. doi:10.1038/s41598-020-65058-1 · other copiesQuoted passage: a description; LCA of pod packaging only (coffee and machine use left out) for one 236.6 mL serving; plastic and PLA-based compostable pods; US university..
  13. BMestdagh, F.; Glabasnia, A.; Giuliano, P. (2017). The Brew – Extracting for Excellence. In: Folmer, B. (ed.), The Craft and Science of Coffee, Academic Press, ch. 15, pp. 355–380. doi:10.1016/B978-0-12-803520-7.00015-3 · other copiesQuoted passage: a description; Textbook chapter on brewing; general statement about pod and capsule espresso systems, no study data..
  14. AEPO Technical Board of Appeal 3.2.04 (2006). Decision T 0452/05 (Coffee pads) of 30 August 2006 on European patent 0 904 717. European Patent Office, Boards of Appeal.Quoted passage: a description; Order of the appeal decision on EP 0 904 717 (proprietor Sara Lee/DE N.V.), 30 August 2006..
  15. AOrrje, E.; Fristedt, R.; Rosqvist, F.; Landberg, R.; Iggman, D. (2025). Cafestol and kahweol concentrations in workplace machine coffee compared with conventional brewing methods. Nutrition, Metabolism and Cardiovascular Diseases 35, 103933. doi:10.1016/j.numecd.2025.103933 · other copiesQuoted passage: the authors’ own result; Home drip brews of five medium to dark roast arabica brands (≈7 g per 1 dL) through two kinds of paper filter; Sweden; medians and ranges..

Tier A · authoritative · B · trade and expert · C · general. Supporting quotes for every source are in the data version of this entry. If a publisher’s site refuses access, try the doi link or “other copies”.

The literature for this entry was last searched on 27 Oct 2026. A statement that no source consulted for this entry shows something refers to the sources above; newer or missing work may exist.

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