Having read extensively on that case, my opinion changed. I now consider the lawsuit baseless and the verdict primarily the result of a sympathetic plaintiff and an unsympathetic defendant (the stereotypical sweet old lady vs the stereotypical evil money-grubbing mega-corp).
Their coffee is just as hot nowadays and to lower the temperature to the degree to where the effect on Stella would have been meaningfully different would result in lukewarm, under-extracted coffee that fewer people would be interested in. Further, the sheer quantity of Mcdonalds coffee moved every year without incident implies user error, rather than product error.
Yes, I know what the jury said and how they divided up the blame. I disagree with their conclusion.
What you say about the coffee temperature is true as far as I've been able to determine, but didn't McDonalds change their cup design in response to the injury? From what I understand, the cups they used at the time were prone to collapsing.
> and to lower the temperature to the degree to where the effect on Stella would have been meaningfully different would result in lukewarm, under-extracted coffee that fewer people would be interested in.
Hot water systems in homes are generally set to not go hotter than 120F, because much hotter than that could burn somebody in seconds. 120F is a bit more than "lukewarm" (which I take to be an exaggeration), but is nevertheless cooler than anybody serves standard coffee at. 140F (60C) water can give you third degree burns in 5 seconds.
(disclaimer: quick back of the envelope research, mistakes might have been made, void where prohibited, kids eat free)
Stella's own doctor testified[1]:
>Lowering the serving temperature to about 160 degrees could make a big difference, because it takes less than three seconds to produce a third-degree burn at 190 degrees, about 12 to 15 seconds at 180 degrees and about 20 seconds at 160 degrees.
The NCA (a coffee industry group) recommends[2] holding at a temperature of 180-185, due to "rapid cooling", and consuming at or below 140.
Stella's injuries were exacerbated by:
* The hot coffee permeating through thin sweatpants and being held against the skin.
* Her age - 81 years old at the time of the injury. Older skin is damaged more easily[3], and would also have implications for her mobility (how fast she could remove the soaked sweatpants)
Some experiments [4] show that coffee served at 180 will cool to around 162 in 5 minutes, 148 within 10, and 138 within 15. 70% of Mcdonalds business is through the drive-through [5], so must customers would be getting their coffee to go.
The question I'm unable to find a satisfactory answer for is how long it takes the average customer to receive their order and return home. I could probably figure that out if I knew how far the average customer was from their store, but that information is not readily available.
If holding at 180 results in optimum drinking temperature of around 130 in about 15 minutes (per 4), then this is the optimal temperature to hold at for product quality if the average customer lives within 15 minutes of a Mcdonalds.
If you were to hold at 160, using the info from [4], the coffee would fall below this optimum temperature in about 10 minutes and require reheating, which alters the flavor.
[3]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3377829/ (It is widely accepted that elderly burn patients have significantly increased morbidity and mortality. Irrespective of the type of burn injury, the aged population shows slower recoveries and suffers more complications.)
Do people really buy Mcdonald's coffee, drive home, and then drink it? I'd have thought most people consume their drive through stuff while still in their car.
Yeah, I do that all the time. (I mean, I certainly do now, but even before the pandemic I would usually wait to get home before eating my drive-through meals.)
Their coffee is just as hot nowadays and to lower the temperature to the degree to where the effect on Stella would have been meaningfully different would result in lukewarm, under-extracted coffee that fewer people would be interested in. Further, the sheer quantity of Mcdonalds coffee moved every year without incident implies user error, rather than product error.
Yes, I know what the jury said and how they divided up the blame. I disagree with their conclusion.