87. Eigenfruit Pie

(Epistemic status: project idea that I am reasonably confident is actually achievable. Feedback, independent experimentation with shared results, and especially alpha-testers all decidedly welcome. There's someone who this post would have been for, in a brighter kinder universe, but this is not that possible world and he will never read this. It's not for him and he will never get to eat anything I make. So it's for MEG, IL, and TT instead, and all my other friends who appreciate good experimental desserts. And also the Philly Pies. Go birds; eat your batteries; third championship fornever.)

  

I can't remember quite when I first came up with this idea. Maybe it was after reading up on the Tree of 40 Fruits pictured above. Maybe it was after reading that passage about kitchen trees producing different kind of snackable fruit year-round in Too Like The Lightning. Maybe the seed of it was planted in me while wandering through a farmer's market one afternoon. I had a vision, both sight and taste/smell, of a kind of pie that didn't yet exist; something hyperreal, sweetly succulent and fruity, and bafflingly indistinct. Whatever the origin of the concept, I want to make a proper eigenfruit pie like nothing else.

So what do I mean by an "eigenfruit pie"? A proper eigenfruit pie would have to satisfy several conditions in descending order of priority.

• An eigenfruit pie would have to be a delicious pie in and of itself. If it's not a good pie, what's the point of making it at all?
• Subject to the above, an eigenfruit pie would need to be intensely, vibrantly fruity. An eigenfruit pie must be an exemplar among fruit pies, or why try so hard to make something new?
• Subject to both of the above - and this is the kicker - people eating an eigenfruit pie should find it as hard as reasonably achievable to figure out precisely which fruits went into the pie.
• Subject to all three of the above, the desired subjective experience of someone eating a slice of eigenfruit pie is roughly: "Oh. OH! THIS is what a fruit pie is supposed to be like, unbound from being any particular fruit." I want something that produces the experience of some transcendent Platonic ideal of Fruit, a hyperreal essence of what a fruit pie should ideally be. I want it to max out the principal component of "fruitiness" extracted out from and orthogonal to all specific fruit identities.
• Subject to all four of the above, I want it to be (largely) natural, with one notable exception I'll mention later. It shouldn't require artificial fruit flavorings or overcomplicated molecular gastronomy techniques. It should be something that can reasonably be made or at least approximated by any strong home chef with access to a reasonably well-stocked supermarket or farmer's market.

This feels extremely achievable, if I try hard, believe in myself, overcome my skill issues, do a bunch of experimentation and gradient ascent, and spend a bunch of money on fruit. And it's not even my first time coming up with an idea for a dessert that's meant to recapitulate, refine, and produce an intoxicatingly hyperreal version of a dessert - that would be sixspice buns, the recipe for which I've kept tweaking since I posted "21. Several Delicious Scalable Recipes for Posterity ", and maybe I'll write a post some time about what the thought process was behind sixspice buns. But the two concepts share a core desire, a core vision: to perfect and augment something familiar, but in a way, with better techniques, and resulting in something almost too wonderful to bear.

But if sixspice buns are warm spice against the chill of winter, breakfast-time and snacks, pure decadence, and a known quantity (cinnabon-style cinnamon rolls) with the good put in and then some and then some more; then eigenfruit pie will be the rich bounty of summer fruits, dinner and other mealtimes, very nearly a hearty meal in and of itself (so much fruit! practically healthy!), and the abstraction and instantiation of an entire class of desserts (fruit pies). I am under no delusion that it will be easy.

What have I tried in the past? I've actually only ever put this through a few iterations with mixed success, mostly because I didn't have much of an audience for them but Grandma Kim, who - bless her - would probably tell me just about anything I made for dessert would be great. The lack of focused taste-testing was acceptable for formulating sixspice buns; all that took was the use of a well-known spice blend in a manner that was slightly unconventional but pretty obvious if you think about it, the use of one specific dough-conditioning technique that anyone with a basic encyclopedic knowledge of baking and pastries would identify as ideal, and to make sure to put the good in at every step. Easy as... well. That said, here's the version of eigenfruit pie filling that I last tested back in May 2025:

• 2 honeycrisp apples, peeled and sliced fine
• 4 red plums, pitted and sliced fine
• a quart of strawberries
• a quart of raspberries
• a pint of blackberries
• 2 large spoonfuls of apricot-raspberry jam
• 2 tbs corn starch
• ~2c white sugar
• 8 packets dried lemon juice
• vanilla paste, a pinch of salt, and bay leaves
• After washing and prepping the fresh fruit, add all of it to a jar with the sugar and seasonings. After macerating, pick out the bay leaves and separate the fruit from the runoff. Slurry the corn starch with some of the runoff, then add it, half the remaining runoff, and the jam to a pot; simmer to reduce. Once done, recombine and use.

The major issues here were excessive moisture, poor consistency, excessive harshness of the lemon juice, and excessive ease of distinguishing fruits. Plus, it didn't sparkle. Not sure how to explain that one apart from "it wasn't the kind of magical it needs to be and that sixspice buns are". Naturally, the pie crust can be optimized separately from the filling, and frankly I might well just buy suitable pie dough for early tests; it might well be what I need, given how bad I am at making pie crust. As a side note, the texture should be chunky, not blended together. A way you could cheat at the difficulty of distinguishing fruits at the expense of pie quality would be to literally blend a bunch of fruits together, but that would both be less appealing as a pie and also likely cause a lot of runoff water. That's part of why the desiderata above are rank ordered! It's also worth noting that blind baking is a thing; I recommend blind baking any pie crust.

How will I know when I've managed it? I've pinned down five major "review desiderata" that will help me know, as partially given by the responses I enjoyed causing and hearing about from people who really liked sixspice buns.

• Technical correctness. I'll know I've got a good process for making eigenfruit pie when there are no obvious flaws to point at. No soggy bottom, a properly flaky crust, a good balance of acidity, a good consistency of filling, and a solid depth of flavor.
• Flavor intensity. I'll know that my fruit mix and seasoning picks for making eigenfruit pie is solid when the fillings come out vibrantly fruity; when I've dialed in the ratio of brown to white sugar, figured out the right amount of salt, have the fruit flavors playing off against each other, and the herbs and spices blend smoothly into the overall flavor rather than being conspicuous.
• Complexity and mystery. I'll know that I have the fruit picks, ratios, and preparation right when the pie comes out as something that rewards careful attention and an attempt, ideally a necessarily strenuous and extremely noticing-rewarding one, to pick out as many individual fruits as possible. But on the other hand, it should indeed be really quite hard to pick out more than one fruit confidently and more than two or three as easy educated guesses, and should be very easy to overlook some and feel awed by the mystery. Nerd-sniping would be a plus too - I'll know I've hit this one when the pie distracts people, trying increasingly hard to pay careful attention to their senses to try to guess the fruits, sticking their noses in their slice and carefully crushing bits between their fingers.
• Renown. I'll know that the pie as a whole is ready for prime time when people start seeking me out when I mention that I've brought some to an event, or demanding the recipe, or telling their friends sight unseen to, as IL told TT, "eat whatever this is that Lorxus wants to give you".
• A certain ineffable something. The sparkle I mentioned earlier. The feeling of a puzzle clicking gently into place; the sensation of knowing for sure that you've never had anything quite like this before; the difficulty of picking out any given fruit from the chorus.

So what's the plan now? The next time I test this, here's the approximate recipe by weight:

• 4 parts Granny Smith apple, peeled and sliced thinly
• 4 parts nectarine, pitted and sliced thinly
• 3 parts red plum, pitted and slicd thinly
• 3 parts hybrid berries mix (marionberry/olallieberry/loganberry, replacing blackberries/raspberries - could also stick with raspberries and blackberries but they're easier to notice)
• 2 parts strawberries
• 2 parts dried cherries (to concentrate flavor and absorb some water)
• 1 part rhubarb
• A small amount of gotgam (Korean dried persimmon) or Fuyu persimmon
• ~2c white sugar
• ~1c brown sugar (the sugar amount is definitely in ratio but not in absolute amount)
• possibly some boysenberry or marionberry jam 
• vanilla paste, ~1/4 tsp cardamom, possibly a pinch(?) of star anise, possibly orange zest, sufficient salt
• tapioca starch to thicken
• After washing and prepping the fresh fruit, add all of it to a jar with the sugar and seasonings. After macerating, separate the fruit from the runoff. Slurry the tapioca starch starch with some of the runoff, then add it, half the remaining runoff, and any jam to a pot; simmer to reduce. Once done, recombine.

I'm also thinking about how best to prepare the pie crust before baking; I'm thinking I'll use the remaining runoff not used in the reduction to brush the top pie crust with before sprinkling with sugar, ideally turbinado. I might also try cooking the fruit a little bit before filling the pie crust. I'll just have to figure it out.

It excites me to think about this high-concept pie. I delight in making things that push the bounds of the real; mundane-seeming things that bring about pleasant sensory experiences not generally thought possible. So... feeling up for a slice of the hyperreal à la mode? It'll probably ruin all other lesser fruit pies for you, but it'll be worth it.