I am an organic chemist possessed of the very finest mind and trained within the most rigorous of gustatory experiences - industrial petrochemistry. As I thrust the masher within the pot and the beige lumps extruded into starchy dreadlocks, my mind flew into furious cogitation. Would I be humbled by a side dish conquered by Hibernians? Ha!
The substance of mashed potatoes preponderantly consists of discoidal insoluble starch particles whose surfaces strongly interact with interstitial water, and each other. That this is also the fine structure of library paste hints at the disaster aborning. I thought of cold cream and grease and the phase inversion phenomenon that interconverts them.
Consider a vessel filled with vegetable oil and water. Shake it heartily, set it down, and watch the oil float to the top and the water sink to the bottom. If you now add a very small percentage of long, thin molecules whose heads are extremely soluble in water but not at all in oil, and whose long tails love oil and hate water, an amazing transformation occurs when you again shake. The stuff is called surfactant. Its long molecular tails bury themselves in the oil droplets with heads left protruding into the water. It stabilizes the oil/water compote at its interface to yield an emulsion of oil droplets floating in a water continuum.
If the surfactant is lecithin in egg yolks, you have salad dressing. If you really beat on it to disperse the oil droplets more finely, you have mayonnaise (aïoli, in neighborhoods that hire poverty as servants). If you start with mineral oil, the latter is called cold cream. If you beat it too long and have too much oil there will be a phase inversion as the oil drops suddenly coalesce into the continuous phase and the water appears as discrete droplets. In a pinch and with lots of muscle you can convert cold cream into bearing grease.
I was mashing and mashing more and more desperately as the glutinous mess filling the pot more and more closely resembled spackling compound. Solvent parameters and surface energies flooded my brain as I desperately sought to discern a mechanism by which those naughty starch particles could be separated in space to create a smooth glide between tongue and palate, not forgetting to throw in some suitably stabilized and unctuous goop to ameliorate gagging. I suspected that a squirt of dishwashing liquid followed by a shot of WD-40 was not a satisfactory answer.
Protein, that was the ticket! Hydrophilic and hydrophobic amino acid residues can create regions of protein separated in space, some of which adore water, some of which crave oil. What would Mother NEVER put into mashed potatoes? Milk products! I thought about all those jolly casein molecules imprisoning microscopic butterfat globules and my heart beat just a little bit faster.
Would I sneak some milk into this rapidly stiffening mess? Nah, too watery. I needed high concentrations of active materials. Butter? Nah, butter is confiscated by Federal decree from all dairy farms to protect the citizens of these great United States from becoming innocent victims of arteriosclerosis and thereby committing suicide by eating it. Butter is stockpiled for government officials' dining only. Margarine? Nah, too greasy and with trans-fatty acids precipitating arteriosclerosis. Either way, phase inversion had put the wrong component as the continuous phase. What was between milk and margarine? Sour cream!
I snuck a dollop of sour cream into the mashed mess and before my widening eyes the crumbly dreadlocks of mortified starch disintegrated into satiny velvet swirls. Little starch particles had their invidious machinations thwarted by molecular layers of protein encapsulation and miniature emulsified oil ball bearings. It was probably not even toxic. I threw in another white plop for good measure, added a crushed garlic clove, stirred vigorously, and presented the final result to She Who Rules the Kitchen - and it was good.
It WAS good! Twenty years of schooling and another fifteen in research had marshaled their dreadful power to bring forth the quintessential pot of mashed potatoes. I will start the patent search on Monday (including a squirt of dishwashing liquid followed by a shot of WD-40, hoping that the patent examiner had never eaten at my mother's table).