laundry dried outside smells different because it has different aroma chemistry that combines hydrocarbons from outdoor air, UV light from sunlight, and water from the damp fabric: https://twitter.com/jimnormsmith/status/1246273874502643713">https://twitter.com/jimnormsm...

Pentanal, hexanal, heptanal, octanal, and nonanal are some of the molecules created when the UV light photo-oxidizes long chains of carbons on the surface of the laundry; these compounds are in a lot of foods and other aromas flavors as well

Pentanal is in olive oil, some fruits, fermented wines, and cilantro, and smells winey/bready/fruity/nuttyhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="🍞" title="Bread" aria-label="Emoji: Bread"> https://abs.twimg.com/emoji/v2/... draggable="false" alt="🥜" title="Peanuts" aria-label="Emoji: Peanuts"> https://abs.twimg.com/emoji/v2/... draggable="false" alt="🍎" title="Red apple" aria-label="Emoji: Red apple"> Hexanal is responsible for fresh and green top notes in tons of edible plants like citruses, strawberry, and cucumberhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="🍃" title="Leaf fluttering in wind" aria-label="Emoji: Leaf fluttering in wind">https://abs.twimg.com/emoji/v2/... draggable="false" alt="🍊" title="Tangerine" aria-label="Emoji: Tangerine">https://abs.twimg.com/emoji/v2/... draggable="false" alt="🍓" title="Strawberry" aria-label="Emoji: Strawberry">https://abs.twimg.com/emoji/v2/... draggable="false" alt="🥒" title="Cucumber" aria-label="Emoji: Cucumber">

Heptanal is also fresh and green, with herbal, cilantro, and fatty notes. https://abs.twimg.com/emoji/v2/... draggable="false" alt="🌹" title="Rose" aria-label="Emoji: Rose">https://abs.twimg.com/emoji/v2/... draggable="false" alt="🌱" title="Seedling" aria-label="Emoji: Seedling">https://abs.twimg.com/emoji/v2/... draggable="false" alt="🌾" title="Ear of rice" aria-label="Emoji: Ear of rice"> octanal is more citrusy-waxy, with green-ness as a more minor component https://abs.twimg.com/emoji/v2/... draggable="false" alt="🍊" title="Tangerine" aria-label="Emoji: Tangerine"> https://abs.twimg.com/emoji/v2/... draggable="false" alt="🥕" title="Carrot" aria-label="Emoji: Carrot"> https://abs.twimg.com/emoji/v2/... draggable="false" alt="🍋" title="Lemon" aria-label="Emoji: Lemon"> nonanal has citrusy, cucumbery, melon, coconut, and rosy qualities https://abs.twimg.com/emoji/v2/... draggable="false" alt="🍋" title="Lemon" aria-label="Emoji: Lemon"> https://abs.twimg.com/emoji/v2/... draggable="false" alt="🌹" title="Rose" aria-label="Emoji: Rose"> https://abs.twimg.com/emoji/v2/... draggable="false" alt="🥥" title="Coconut" aria-label="Emoji: Coconut"> https://abs.twimg.com/emoji/v2/... draggable="false" alt="🍈" title="Melon" aria-label="Emoji: Melon"> https://abs.twimg.com/emoji/v2/... draggable="false" alt="🥒" title="Cucumber" aria-label="Emoji: Cucumber"> https://abs.twimg.com/emoji/v2/... draggable="false" alt="🥔" title="Potato" aria-label="Emoji: Potato">

all of these molecules have basically the same structural pattern, a carbon-oxygen-hydrogen head with carbon tails of different lengths. Plants usually create aldehydes by enzymatically altering fats, which have the right carbon tails.

Hexanal (in laundry and in strawberry/cucumber) has a similar structure to hexenal (one letter difference in their names!), one version of which is created by grasses by slicing up fatty acids when their tissue is damaged (like by mowing)