Corpse-starch: What the lore actually says, part II - Soylens Viridians and Slab Boogaloo

In a previous very extensive post available here: https://madministratum.blogspot.com/2025/05/corpse-starch-what-lore-actually-says.html) it was thoroughly shown that corpse-starch, explicitly made from people, is well established in the lore, and is used on multiple planets and at least to some extent by the Guard.

In this post we will look at Slab and, especially important for this topic, Soylens Viridians. We will start with the latter.

Soylens Viridians

Soylens Viridians is often conflated with corpse-starch – for very understandable reasons. Indeed, this was the case on Lexicanum (which was fixed due to my original Reddit post) and the Fandom Wiki (which at the time of writing is still wrong), which were both poorly supported by sources on these topics (and in the case of Lex, it was spelled incorrectly as Soylent Viridian).

Soylens Viridians is often also claimed in many fan discussions to actually not contain human corpses, or to be proof that the notion of corpse-starch is exaggerated (which, as the big list in the previous post shows, is not true regardless of the status of Soylens Viridians itself).

Its name is, of course, a reference to Soylent Green, the food product secretly made out of people which features in the eponymous classic dystopian scifi film of 1973. This, you might think, suggests that Soylens Viridians must be made of human remains too, and thus a form of corpse-starch – but it isn’t so straightforward.

So, let’s see what we know about it.

It was introduced in the Ciaphus Cain books (very aptly, given their humours approach), where it gets various fleeting mentions. I have checked over all the Cain stories I have access to, but haven’t been able to check some of the short stories, so perhaps I’ve missed some mentions there. It first appeared in the short stories 'For the Emperor' (spelled Soylens Veridiens) and 'Caves of Ice', reprinted in Ciaphas Cain: Hero of the Imperium. Here are the mentions:

I'd been steeling myself to face a plateful of soylens viridiens or something equally unappetising the first time I wandered down to the mess hall, only to find a pleasantly appointed dining room which wouldn't have looked out of place in a smart hotel, and was immediately assailed by the mouth-watering odour of sauteed grox."

Ciaphas Cain: Hero of the Imperium, p. 275.

"‘So what do they taste like?’ Jurgen asked. I stopped tuning out Logash’s prattling to gather that his monologue on the subject of the ambulls’ life cycle, social structure, and habitat had finally yielded some useful information. Apparently there had been a number of attempts to domesticate the things as a handy source of meat on desert worlds.'

‘Rather like grox, I’m told.’ Logash looked a little uncomfortable, and I clapped him on the shoulder.

‘Excellent, I said. ‘We'll send a scavenging party back to recover the carcasses once we've cleaned out the nest’ Ail the refinery had to offer in the way of cuisine was a dozen different varieties of soylens viridians, which had already begun to pall, despite being fresh from their own vats. Of course, we'd brought our own supplies along, but a nice fresh steak would lift my spirits nicely, I thought. Besides, the creatures had been eating the miners, so it seemed fair enough to return the compliment.

‘Good idea, sir’ Jurgen said with relish. Logash looked a little green for someone so heavily augmented. Maybe he was a vegetarian, if he still bothered eating at all.

Ciaphas Cain: Hero of the Imperium, p. 355.

It was while I was reflecting thus, and enjoying an unexpectedly lavish meal of the soylens viridians which the tech-priests who ran this palace of wonders had so generously provided from their own resources, that Colonel Kasteen summoned me to the command centre.

Ciaphas Cain: Hero of the Imperium, p. 373.

By the time Kasteen called a full meeting to discuss the situation I'd managed to grab a little sleep, a lot of recaf, and a hot meal (just soylens viridians again, but for some reason I'd gone off the idea of retrieving an ambull steak), and was beginning to feel tolerably human once more.

Ciaphas Cain: Hero of the Imperium, p. 425.

So, it’s mentioned, but we get little actual information about what it is, or how it is made. There are some interesting hints that might point towards a running joke, though, which I’ll explain below (and which, to be very upfront about this, is just one reading of the material, and very likely not the most likely - I include it for the sake of interest).

Soylens Viridians then featured again in The Greater Good, where we get more specific details.

Fortunately the Mechanicus maintained a number of comfortably furnished suites near their inner sanctum for the convenience of visiting Imperial dignitaries, which they seemed to consider me as, so I was less incommoded than I’d feared, but I certainly missed the artistry of Zyvan’s personal chef, the bland diet of soylens viridians on which I was obliged to subsist for the most part wreaking predictable havoc on my digestion. Footnote 69.

The Greater Good, p. 88.

And footnote 69, an in-universe annotation by Inquistor Amberely Vail, states:

[69] Consisting as it does mainly of reconstituted pulses, the consequences of relying on it as a staple become all too evident remarkably quickly, particularly in a confined space.

The Greater Good, p. 279.

We also have this (key parts in bold, but I’ve add a longer quote to provide context):

'There are ambull down there?’ I asked, astonished at the idea that the polluted wasteland could sustain any life at all, let alone the huge, aggressive burrowers.

Kildhar nodded. ‘An entire ecosystem, in fact. My title is far from honorary, I can assure you.’

‘I’m sure it’s not,’ I said. ‘I was just wondering if there’s any chance of a steak when we get back.’

‘It’s possible, I suppose,’ Kildhar said, looking faintly puzzled. ‘Some of the surface workers hunt them if the opportunity arises, but the consumption of animal tissue is a singularly inefficient way of ingesting nutrient.’ She looked disparagingly at the remains of the bap in my hand. ‘Soylens viridiens is far more convenient, and provides everything necessary for continuing good health.’

‘Except flavour,’ I said feelingly. ‘And texture.’ My mouth flooded with saliva at the thought of a sizzling chunk of dead flesh.

‘Oh.’ Kildhar looked more baffled than ever. ‘Those.’

‘I’ll see what I can do, sir,’ Jurgen said, with quiet confidence, and my spirits rose at the prospect of a proper meal at last. My aide’s talent for scrounging bordered on the preternatural, and I was certain that if ambull steak was to be had anywhere in the hive, he’d find it, even if it meant bagging the brute himself.

The Greater Good, p. 91.

Kildhar being a member of the Ad Mech.

‘How soon can we get there?’ I asked, practically salivating at the prospect of the hot meal and mug of recaff waiting for me at our destination. Even soylens viridiens seemed palatable right about now.

The Greater Good, p. 181.

So, we get some inconsequential mentions again, but also, seemingly, a clear answer as to what is made from: reconstituted pulses, which can make people gassy.

Many fans take this one footnote as a definitive answer and a refutation of the fact that Soylens Viridians might contain human corpses. It is just one comment, though, from one character, in one book series. A high-ranking, well-informed character, in the form of an Inquisitor, sure. But that’s no guarantee that Amberley is correct about this issue, or that all forms of Soylens Viridians are the same (and important point I will return to at the end).

But let’s think a bit deeper about the possible intended humour. There is obviously a joke at play here, as Sandy Mitchell named the foodstuff after a movie with an incredibly famous twist, where it turns out “Soylent Green is people!”. 

Sometimes the joke is construed to be that we, the readers, expect Soylens Viridians to be corpse-starch, as we are familiar with the twist of the film and general pop cultural references to Soylent Green. So, here, the twist to confound our expectations is actually that Soylens Viridians is not made of people, but actually just of legumes. Moreover, in the original 1966 book that the film was based on, Make Room! Make Room!, there was no twist. Soylent Green literally was just soy and lentils. So maybe Mitchell is providing a nod towards this. And you can read it that way, and honestly that is likely to be the actual intended meaning (somebody should ask Mitchell).

But it could perhaps also be read as more of a meta-joke in another way: people in 40k believe it to be made of something unnoteworthy like legumes. Just like people in the movie thought Soylent Green was made form plankton... But, of course, Soylent Green was secretly made of people… Perhaps Mitchell is, instead, recreating the same dynamic with Soylens Viridians? 

And I think the scenes where Soylens Viridian appears can be read with this in mind.

As shown in the quotes from Hero of the Imperium, there is a running narrative thread that Cain is savouring for some Ambull, to sate his craving for meat. Yet, after eating his Soylens, Cain says: “for some reason I'd gone off the idea of retrieving an ambull steak”. Perhaps, because, he had in fact actually just eaten some meat. Kind of, anyway, and in a disgusting form. Though it must be acknowledged that this particular line is much more likely to be because Cain was put off by having encountered Flayed Ones wearing Ambull flesh.

It would also make his thought that “Logash looked a little green for someone so heavily augmented. Maybe he was a vegetarian” quite ironic: because, the implication could be, that Logash in fact does eat meat – human meat, at that, and with a green tine to boot – via Soylens Viridians.

We could also perhaps see this bit:

‘Except flavour,’ I said feelingly. ‘And texture.’ My mouth flooded with saliva at the thought of a sizzling chunk of dead flesh

as also being ironic. Cain perhaps does get his flesh – it is just sometimes coming from humans, and processed until it lacks all flavour and texture, in his Soylens.

Now, this is obviously just one way of reading these scenes (and likely not the original intended meaning), and not at all ‘proof’ as to Soylens Viridians containing corpses. Let's be clear about that. I just think there is enough ambiguity that it can be read in that way if so preferred AND it fits in nicely with what we know about corpse-starch in 40k (and, interestingly, fits with how the lore has developed since Mitchell wrote those books! Even if it wasn't his original intention!).

And to add more lore-informed conjecture: Do I think the Ad Mech, who are noted in these stories to produce Soylens Viridian, would have any scruples about tossing corpses into their Soylens Viridians processing machines? No. If anything, the Ad Mech are more callous towards human life and dignity and more likely to view humans as purely resources to be used then the wider Imperium. Which takes some going, but they manage it. And, as the prior post showcased, they are involved in manufacturing corpse-starch. 

Moving on to another source, in the computer game Necromunda: Hired Gun, you can enter a Soylens Viridians refinery which is used to process human corpses into food. So here, there seems to be direct conflation between corpse-starch and Soylens Viridian.

There is even a sign which states:

FOR YOUR OWN SAFETY DO NOT INGERATE* RAW SOYLENS VIRIDIANS

MESSAGE PRESENTED BY CORPSE GUILD WITH THE CONSENT OF THE PALATINE ENFORCERS

*whatever this means? Perhaps it means “ingest”, as in: don’t eat the raw, unprocessed flesh. Because that’s how you get Corpse Grinder Cults…

Image here: https://www.reddit.com/r/GamingDetails/comments/pm0qui/in_necromunda_hired_gun_2021_in_a_factory_that/

A case of the computer game designers following fanon conflations of corpse-starch and Soylens Viridians, perhaps? Or intentionally making a connection between corpse-starch and Soylens? Regardless, it is now still part of the lore that there is some link between the two.

Slab

Things are generally more straightforward with slab, though there is again some possible room for ambiguity. Slab has been most fully fleshed out (heh) in the short story 'Against the Grain', where it is shown as being made from heavily-processed Grox meat:

A long, rectangular room stretched away from Efrem, the doors closing gently behind him. A plushly carpeted aisle, flanked by white marble columns, led to a large black desk. The columns formed a sort of interior arcade. On one side, a grand aperture of shroud glass offered a panoramic view of the Swathe; on the other, a gallery of framed line sketches depicted archaic agri-machines – tractor-engines, threshers, combines and irrigators. One piece stood out from the rest, a zoological study of the grox. The artist had painstakingly rendered the saurian from several angles, and included close-up vignettes of teeth, claws and tail.

‘Remarkable creatures…’

The man sitting at the desk didn’t look up from his writing, an auto-quill scratching noisily on the sheaves of parchment laid out before him.

‘Herd beasts, discovered by the first Imperial settlers. Harvested for meat, hide for leather, teeth and claws for blades. Snout to tail,’ he went on, the cybernetic limb that had been furiously scribing pausing as he did. ‘I apologise,’ he added, a warm smile changing the aspect of a young, dark-skinned face, and indicated to the parchments. ‘Ledgers. The need for slab has never been greater. There is war out in the void, or so I’m told.’

Slab, a heavily processed, high-protein meat. Cheap to manufacture, slow to degrade. Perfect fodder for troops out in the void.

‘When isn’t there,’ Efrem remarked as he approached the desk. He felt like a cadet in the presence of his discipline master.

The man conceded this with a nod, and rose to his feet. His hair was black, neatly cut. He wore a simple tan suit, military in aspect. His umber waistcoat looked stiff, and Efrem wondered if it was subtly armoured. An ebony ring shone on his left hand, the sigil upon it too difficult to make out in the dim lighting.

‘Docile, but savage if roused to anger. Omnivorous, that is to say,’ added the man, ‘they will eat anything. Grain, leaf, flesh and bone. Even cloth, plastek.’

‘Remarkable,’ echoed Efrem but without the zeal.

However, it was revealed that Ork corpses were secretly being fed into the processing machines:

He emerged onto a gantry that overlooked an immense hangar below.

Haulage servitors lumbered in dull-eyed trains, carrying bales of plas-wrapped meat fresh from several large and noisy grinders. The air stank with it, cold and bloody and reeking of churned flesh. Rank upon rank of thawed grox carcasses were being fed into the machines, the herd beasts rendered into slab and destined for hungry Militarum bellies.

But that wasn’t all.

A second meat supply supplemented the first, and Efrem balked at the sight of it. A great heap of corpses were being thrown into the grinders. Limp and blank-eyed, shot through with las-beams or bullet holes. A tangle of malformed limbs, and tusks and hooves and brutish snouts, and slit-nosed faces and lithe bodies. He recognised greenskins and a few others. Heat flared across his skin, despite the cold room, and his heart hammered as the barrage fell upon him again, taking his leg, tearing him apart just like the meat in those wretched fucking grinders. The sheer horror of it, wondering how far the conspiracy went, how deep. Most of Varangantua’s citizens hadn’t ever seen a xenos, and those that had, not in decades. Many thought aliens were just a myth.

Efrem fought the urge to vomit, knowing it might reveal his presence to the handful of bored-looking House Mermidian armsmen roaming amongst the servitors. The bales were being loaded onto several large but currently disengaged anti-grav pallets.

It looked like a shipment was being readied for departure.

The magnitude of what he was seeing sank in like a cold blade. It was headed for the void, to Throne only knew where, to the Militarum, to the Navy. Entire regiments subsisting on this tainted filth…That was how Karridinus had managed to increase its quotas: they had found another meat source.

Now, Orks are of course big sentient fungi, so technically there was still no “meat” being included, I guess. But if they were willing to throw in Xenos bodies, might they not also be willing to use human corpses, which is already a standard practice elsewhere?

Yet slab was actually first introduced in Gaunt’s Ghosts, where it is described thus (key part in bold):

Slab is pretty gruesome stuff. Pressure-treated down from any and all available nutritional sources by the Munitorum, it has no discernible flavour apart from a faint, mucusy aftertaste, and it looks like grey-white putty. In fact, years before at Schola Progenium on Ignatius Cardinal, an acquaintance of Gaunt’s had once kneaded some of it into a form that authentically resembled a brick of plastic explosive, complete with fuses, and then carried out a practical joke on the Master of the Scholam Arsenal that was notable for both the magnificent extent of the disruption it caused, and the stunning severity of the subsequent punishment. Slab, as it’s known to every common Guard lasman, comes canned and it comes freeze-dried, it comes in packets and it comes in boxes, it comes in individual heated tins and it comes in catering blocks. Company cooks slice, dice and mince it, and use it as the bulk base of any meal when local provision sources are unavailable. They flavour it with whatever they have to hand, usually foil sachets of powder with names like groxtail and vegetable (root) and sausage (assorted). Ibram Gaunt has lived on it for a great deal of his adult and sub-adult life. He is so used to the stuff, he actually misses it when it isn’t around.

‘Of Their Lives in the Ruins of Their Cities’, in Sabbat Worlds: A Warhammer 40,000 Anthology, p. 263.

So, it seems that it can actually be made from other ingredients besides grox (and secret Ork), depending on available supplies. So perhaps slab is a term used for different foods which share a similar final look/form, perhaps being used to refer to different things in different places – the Imperium is unfathomably massive, after all.

Now, this bit:

Slab is pretty gruesome stuff. Pressure-treated down from any and all available nutritional sources by the Munitorum

Does leave the possibility dangling that perhaps "all available nutriotional sources" might include human corpses... especially as we know that the Imperium does definitely use them, at least in some places, and that some Guard regiments are supplied with corpse-starch.

As proof that slab cannot contain corpses, people often point towards Gaunt's own views towards cannibalism, specifically that in His Last Command he executes some cooks for repurposing corpses into food (which makes some of the soldiers sick). And he also says:

“I’m sorry, Ironmeadow, but they have. I was there. On Fortis Binary, food shortages got so serious that the Munitorum started to take corpses from the morgues and process the flesh for food. It was endemic in the hives at one point. A shameful secret your people put behind them.”

His Last Command, p. 110.

A few thoughts:

Corpse-starch seems to commonly be distinguised from cannibalism in the Imperium, with it no longer being seen as cannibalism once the corpses have been properly processed. This is evident on Necromunda, where corpse starch is officially sanctioned and produced by the Corpse Guild, but where eating unprocessed flesh is still taboo - and has led to the emergence of Corpse Grinder Cults.

Regardless, the quote from Gaunt about the events on Fortis Binary shows that he finds even processed corpses to be immoral and shocking. So, it seems that cultural attitudes towards the practice vary a lot across the Imperium. Which is to be expected.

It would therefore be delightfully ironic if Gaunt and his men were unwittingly eating human in their slab, especially as Gaunt is "is so used to the stuff, he actually misses it when it isn’t around". Do I think this is likely to be true? No. But given what we know about the use of corpse-starch in the Imperium more broadly, it could be.

Final thoughts

So, there you go: that's Soylens Viridians and Slab. 

Is Soylens Viridians the same as corpse-starch, as is often thought? Probably not. At least, not always. Because sometimes it seemingly is, at least on Necroumunda. And there do seem to be different varieties of Soylens Viridians, so perhaps some contain human. Indeed, there is also this (bold mine) in a computer game:

Soylens viridians might be filling, nutritious and easy to grow in great vats—but as a foodstuff it has some drawbacks. First, it's utterly bland and flavourless. Second, it looks like green gloop. Third, it's made from any available organic matter. Persistent rumour has it that human corpses are not excluded.

Gladius: Relics of War 

So, while again no confirmation that Soylens Viridian ever does contain human corpses, it is interesting that there is an in-universe rumour about it. Because it's based on truth? Or because rumours and/or knowledge about corpse-starch has made people suspicious of other mass-produced forms of food? It makes perfect sense that in a setting where corpse-starch does exist, people would be suspicious of other processed foods.

Can slab contain corpse-starch? Maybe, but there is no actual examples in the lore, so that is just conjecture. We certainly know it has contained highly questionable and likely illegal ingredients, like Ork.

Given that the true nature of corpse-starch is often seemingly kept a secret, it does leave open the possibility that other food sources such as these could be examples of it, or contain some. But we lack actual explicit examples in the lore to say that this is the case. Is does mean that, regardless of Mitchell's original intention when he wrote the Cain books, that the way the wider lore has evolved since suggests that some Soylens Viridians may indeed include humans.

Anyway, I hope you enjoyed this second course. The next post in this series will situate the Imperium's use of corpse-starch within the regime's broader use of humans and their bodies as resources. Do come back for dessert, won't you?

This was originally a post on r/40kLore on Reddit: https://www.reddit.com/r/40kLore/comments/1hv7up1/corpsestarch_what_the_lore_actually_says_part_ii/