Uploaded August 2026 | Updated September 2026, 2 weeks ago
Head to squarespace.com/lancehedrick to save 10% off your first purchase of a website or domain using code LANCEHEDRICK
This video goes over the science behind pressure and flow and Darcy's Law in espresso extraction, questioning the historical precedent and modern imperative of 9 bar as being the optimal peak pressure for espresso preparation.
Works Cited:
Main paper of the video arguing for poroelasticity of the puck:
arxiv.org/abs/2512.21528
Under pressure: poroelastic regulation of flow in espresso brewing
Radost Waszkiewicz, Franciszek Myck, Łukasz Białas, Maria Puciata-Mroczynska, Michał Dzikowski, Piotr Szymczak, Maciej Lisicki
This uses CT scanning to look at the infiltration stage (first 5 seconds of transient stage)
pubs.aip.org/aip/pof/article/37/1/013383/3332668/Dynamics-of-liquid-infiltration-into-an-espresso
Dynamics of liquid infiltration into an espresso bed using time-resolved micro-computed tomography: Insights from experiment and modeling
Jamie Foster
This paper simulates the effect of the swelling of coffee grounds on porosity and extraction.
researchgate.net/publication/359740383_Modeling_swelling_effects_during_coffee_extraction_with_smoothed_particle_hydrodynamics
Modelling swelling effects during coffee extraction with smoothed particle hydrodynamics
Mo, Navarini
This paper discusses fines migration and effects on permeability and porosity.
researchgate.net/publication/333451051_Mesoscopic_modelling_and_simulation_of_espresso_coffee_extraction
Modeling swelling effects during coffee extraction with smoothed particle hydrodynamics
Navarini and Ellero
This paper discusses particle erosion in extraction.
researchgate.net/publication/354403653_Modeling_the_effect_of_flow-induced_mechanical_erosion_during_coffee_filtration
Modeling the effect of flow-induced mechanical erosion during coffee filtration
Mo, Navarini, Ellero, Johnston
This is the paper referenced going over swelling and erosion together.
arxiv.org/abs/2012.15624
Flow through time-evolving porous media: swelling and erosion
Matias, Coelho, et al
LINKS
__________________
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TIME CUES:
0:00- 9 Bar Dilemma
3:48- Darcy's Law
8:00- Squarespace
9:09- 9 Bar Supremacy
11:00- Mechanisms Over the Years
12:30- Poroelastic Puck
13:45- Darcy's Apex
15:25- Replicating on My Machines
17:23- WhAt AbOuT cReMa?
18:36- Secondary Compaction?
19:59- FLOW Supremacy
22:29- Darcy Shots and Channeling
Head to squarespace.com/lancehedrick to save 10% off your first purchase of a website or domain using code LANCEHEDRICK
This video goes over the science behind pressure and flow and Darcy's Law in espresso extraction, questioning the historical precedent and modern imperative of 9 bar as being the optimal peak pressure for espresso preparation.
Works Cited:
Main paper of the video arguing for poroelasticity of the puck:
arxiv.org/abs/2512.21528
Under pressure: poroelastic regulation of flow in espresso brewing
Radost Waszkiewicz, Franciszek Myck, Łukasz Białas, Maria Puciata-Mroczynska, Michał Dzikowski, Piotr Szymczak, Maciej Lisicki
This uses CT scanning to look at the infiltration stage (first 5 seconds of transient stage)
pubs.aip.org/aip/pof/article/37/1/013383/3332668/Dynamics-of-liquid-infiltration-into-an-espresso
Dynamics of liquid infiltration into an espresso bed using time-resolved micro-computed tomography: Insights from experiment and modeling
Jamie Foster
This paper simulates the effect of the swelling of coffee grounds on porosity and extraction.
researchgate.net/publication/359740383_Modeling_swelling_effects_during_coffee_extraction_with_smoothed_particle_hydrodynamics
Modelling swelling effects during coffee extraction with smoothed particle hydrodynamics
Mo, Navarini
This paper discusses fines migration and effects on permeability and porosity.
researchgate.net/publication/333451051_Mesoscopic_modelling_and_simulation_of_espresso_coffee_extraction
Modeling swelling effects during coffee extraction with smoothed particle hydrodynamics
Navarini and Ellero
This paper discusses particle erosion in extraction.
researchgate.net/publication/354403653_Modeling_the_effect_of_flow-induced_mechanical_erosion_during_coffee_filtration
Modeling the effect of flow-induced mechanical erosion during coffee filtration
Mo, Navarini, Ellero, Johnston
This is the paper referenced going over swelling and erosion together.
arxiv.org/abs/2012.15624
Flow through time-evolving porous media: swelling and erosion
Matias, Coelho, et al
LINKS
__________________
Join my Patreon community at:
patreon.com/lancehedrick
Find me on IG at:
instagram.com/lancehedrick
Find me on Facebook at:
facebook.com/lancehedrickcoffee
My storefront: amazon.com/shop/lancehedrick
Shop ID: amzn.to/48CcpTj
My SECOND Channel:
Lance Hedrick Unfiltered
@LanceHedrickUnfiltered
TIME CUES:
0:00- 9 Bar Dilemma
3:48- Darcy's Law
8:00- Squarespace
9:09- 9 Bar Supremacy
11:00- Mechanisms Over the Years
12:30- Poroelastic Puck
13:45- Darcy's Apex
15:25- Replicating on My Machines
17:23- WhAt AbOuT cReMa?
18:36- Secondary Compaction?
19:59- FLOW Supremacy
22:29- Darcy Shots and Channeling
