Hollandaise vs Mayonnaise | Why One Breaks & One Doesn't скачать в хорошем качестве

Hollandaise vs Mayonnaise | Why One Breaks & One Doesn't

Emulsions like mayonnaise and hollandaise are thermodynamically driven to separate because oil and water hate interfaces—but emulsifiers and viscosity create kinetic barriers that can keep trillions of droplets stable. This lecture explains interfacial tension, lecithin coverage limits, thin-film rupture coalescence, temperature/protein effects, and practical strategies to prevent or rescue a split sauce. This lecture explains why mayonnaise and Hollandaise are beautifully engineered but inherently unstable: they are emulsions—tiny droplets of one liquid dispersed in another that normally does not mix. The core message is that emulsions are not truly stable in a thermodynamic sense. Creating millions (or trillions) of droplets produces an enormous oil–water interfacial area, and the system “wants” to reduce that area by merging droplets and separating into two layers. Emulsifiers from egg yolk—especially lecithin, plus proteins—slow that breakup by lowering interfacial tension and building protective barriers at the droplet surfaces, turning an unstable mixture into a kinetically trapped one. The lecture then breaks down the main ways emulsions fail. Droplets can rise or sink (creaming/sedimentation), clump without merging (flocculation), or—most importantly—coalesce, where the thin water film between two droplets drains, ruptures, and the droplets fuse in a rapid event. It also covers Ostwald ripening, where small droplets shrink while big ones grow because smaller droplets are under higher internal pressure. A crucial practical insight is that whisking is a double-edged sword: it breaks droplets smaller (good), but it also increases collision rates (bad). If you create more interfacial area than your emulsifier can cover, you get bare patches and runaway coalescence—your sauce “splits.” Temperature and salt become the villains for Hollandaise. Warmer conditions speed molecular motion and ripening, and above a narrow window egg proteins can denature and start bridging droplets, accelerating instability. Added salt or acids can change screening and weaken electrostatic barriers, while viscosity strongly improves stability by slowing collisions and film drainage. The finale translates the physics into cooking tactics: control oil-to-yolk ratio, add oil slowly, control temperature carefully, and rescue broken emulsions by re-emulsifying into a fresh yolk. What you will learn: Why emulsions are kinetically stable but thermodynamically driven to split What emulsifiers do at the molecular level (lecithin + proteins at interfaces) The four failure modes: creaming/sedimentation, flocculation, coalescence, ripening Why coalescence happens: thin-film drainage → rupture → rapid merging Why whisking can both stabilize and destabilize (droplet breakup vs collisions) The “emulsifier coverage limit” and why too much oil or too-small droplets trigger splitting Why Hollandaise has a narrow temperature window and how protein denaturation matters How viscosity, salt, and acidity change stability Practical prevention and rescue strategies grounded in the physics Timestamps: 00:00 — What emulsions are and why they suddenly split 01:39 — The thermodynamic drive: huge interfacial area wants to shrink 03:28 — Emulsifiers: how lecithin/proteins stabilize droplets by lowering tension and adding barriers 05:14 — Four breakdown routes: creaming, flocculation, coalescence, ripening 06:53 — Coalescence mechanism: film drainage and rupture 08:04 — Why whisking can destabilize when emulsifier is limiting 09:10 — Coverage limit sets the minimum droplet size and maximum stabilizable area 11:06 — Temperature effects (especially Hollandaise) and protein denaturation 12:48 — Too much oil overwhelms emulsifier capacity 13:53 — Viscosity boosts kinetic stability by slowing motion and film drainage 15:09 — Electrostatics, salt/acid effects, and screening 16:17 — Timescales: why failure can appear suddenly on the minute-to-tens-of-minutes scale 17:33 — Practical strategies and how to rescue a broken emulsion 18:40 — Phase inversion temperature idea and why “near inversion” can be unstable 19:11 — How stability is measured in the lab (droplet size, zeta potential, rheology, microscopy) 20:13 — Emulsion type, emulsifier solubility rules, and HLB intuition 21:24 — Steric stabilization from proteins and why it is salt-tolerant 21:58 — Marangoni flows and how they can delay film rupture 22:58 — Summary of the physical mechanisms behind splitting 23:33 — Cooking recommendations mapped to the physics 24:40 — Final takeaway: soft-matter physics hiding in everyday sauces #Emulsions #Mayonnaise #Hollandaise #FoodPhysics #SoftMatter #Colloids #Surfactants #Lecithin #InterfacialScience