Out on a small planet called Vernar IV located in the Ghan’Shi sector of the Galaxy, there’s a small restaurant and bar called “Tuang’s Taphouse”, which serves food and refreshment to many species, including humans. There’s just one problem: biochemistry.

There’s about 12 sentient, spacefaring races in the Milky Way: the Humans, Qualians, Gordaniran, Amtolites, Vosian, Nekubiak, Seluban, Itaran, Zeydalaan,Jedarik, Tausali and Telenoid. Each of these species has populations who occasionally stop on Vernar IV, and each are known to frequent the bar. My question is, how do you make a bar that can safely feed and serve multiple, often somewhat incompatible, biologies?

The main problems are cross-contamination (since one species can often regularly eat food lethal to another), and knowing what is and isn’t safe for each species. How could you design the restaurant and whatnot to accommodate everyone?

For clarification’s sake all 12 are carbon-based, oxygen nitrogen breathers, who all inhabit planets with mostly the same gravity as ours, and same atmospheric density too. As for equipment, they’re all just wearing normal clothing and spare gas masks.

  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – L.Dutch
    Commented Feb 17, 2021 at 6:13
  • 3
    $\begingroup$ We've seen this movie before. The most important thing is you instruct the musicians to resume playing ... no matter what. :) $\endgroup$ Commented Feb 17, 2021 at 22:39
  • $\begingroup$ grrlpowercomic.com/archives/comic/… $\endgroup$
    – Salda007
    Commented Feb 18, 2021 at 6:53
  • $\begingroup$ Another potential problem: Gordaniran favourite food is Seluban sauté. $\endgroup$
    – Kepotx
    Commented Feb 23, 2021 at 9:46

8 Answers 8



Tuang’s Taphouse is surrounded by kitchens who provide food for galactic Plebians in the food court on one side and the patrons of Tuang's Taphouse on the other. The desired ambiance dictates whether the bar is above (balcony bar - nice for the flying species), below (basement bar - nice for wet species) or behind (mall bar - just sad) the food-court kitchens.

When entering Tuang's, a micro-scale sample of the patron (a few dead skin cells, for example) informs a digital device which menu to show as well as eliminating all of the food items that their DNA (or whatever passes) indicates intolerance for. Of course, the Ryzineans find that disgusting, so they just send a small electrical pulse to an internal bypass that triggers their menu. Conversely, the Blearinos love expelling their mucus on the device, so Tuang designed them for frequent sanitation and acidic environments down to pH 1.2. After the device determines the species of the patron, an "interactions board" gets updated.

When a patron orders, two things happen. First, the interaction boards get updated. Second, orders go directly to the kitchen(s) of choice and proceed according to the cultural expectations of delivery - Xanshians only eat what they catch and four other species refuse to consume anything touched by non-worlders. The D'hColi have religious reasons and it's widely suspected that the Utuairops are just racists, but the others have well documented cases of allergic reaction. A fifth species, the Ryzineans, have such complicated ceremonies around their food service that Tuang's food runners almost never bother, though now-Ambassador Glinea used those ceremonies to launch her diplomatic career.

When a Xanshian orders, new patrons get alerted that when the house-lights turn off and a green spotlight shines on them, they must not leave the spotlight until the house lights turn back on. That frequency of green was chosen as it is the only one reliably visible to all of the patrons. It should go without saying that the doors lock when the spotlights are on.

31 fluid (gas, liquid and intermediate) menu items have documented or suspected reactions, so there are no cups at Tuang's. Woe to any who spills beer on a Xanshian, because they only have 28 seconds to prevent murder if they know how. Single-serve micro-kegs provide beer and other pressurized items. Fluids at atmospheric pressure arrive in the equivalent of sippy-cups.

Lastly, Tuang's employs a part-time xenobiologist to test every food item on every menu against the biology of every species that dines there. The xenobiologist has prepared anti-histamines, anti-toxins, contingency plans and instructions for every expected interaction. As well, they programmed the interaction board to update staff on current dangers and how to fix them. Back when the D'hColi and Utuairops arrived it was extremely lucrative, but these days, they only work when new food and beverage items get introduced.

  • $\begingroup$ Are we talking a high class establishment with gourmet food or a rough-and-tumble everyone for themselves hole-in-the-wall frontier bar with token food? I don't recall anything in the OP about food inspectors. But I DO like the food court idea. Multiple food prep areas would be a must, methinks, if the food was in any way prepared on site. However, the devil that is in the details is the bit about 'occasionally drop in'. What volume of turnover of each species would merit this extravagant design? Would the volume support individual kiosks in order to be profitable? $\endgroup$ Commented Feb 23, 2021 at 1:53

This is not an exobiology problem. This is a problem in present day restaurants

A single molecule of the food that Person A enjoys can kill person B right here on Earth. 1 US citizen needs emergency room medical treatment every 3 minutes from this. 1 in 26 children have had a life threatening attack.

I personally have experience from this. At a alcohol-heavy party in my early twenties I consumed a milk based liqueur shot. 30 minutes later I hooked up with a girl I just met. 20 minutes later she was in an ambulance, as the milk was soy based, and the soy protein in the trace of the drink on my lips and breath triggered an allergic reaction strong enough that her face swole up to the point that she couldn't breathe even after using an epi-pen.

There are 8 main food ingredients that most of us eat every day that can kill a fellow human in minutes: Peanuts, shellfish, soy, tree nuts, egg, milk, finfish, and wheat. There are other ones but those are the ones that kill 90% of us.

For an excellent documentary on this problem, and a fairly detailed tour a restaurant that believes "at a minimum, your meal shouldn't kill you" so goes through a complex process for each customer to make sure they survive their meal, I'd suggest watch "The peanut problem" (Netflix subscription required).

As a summery:

  • Customer sits down, and is given a menu based on their language.
  • The menu is bulky. Each dish is given a full page
    • photo, and full explanation of the ingredients, and their ingredients.
  • Customer orders a meal after consultation with the educated waitstaff
    • No US style "tip so they live" payment, these people need to be smart and on the ball, so paid a decent wage.
    • If a low tipper gets poor service and dies that's bad for the entire restaurant.
  • Cooking is done in batches of similar foods such that no two products are cooked concurrently that could fatally cross contaminate
    • Between batches:
      • All utensils go in the dishwasher
      • All surfaces are wiped down
      • The cook and waitresses change gloves, hairnets, and smocks.
  • Good airflow is needed in the kitchen area too, air should be sucked out a fume hood from the hot plates and into a filter before being vented such that there is zero likelihood of contaminants persisting in the air.

As far as the venue can control, there are two primary opportunities for contamination: in preparation in the kitchen, and at the table.


The easiest way to avoid a dozen biochemistries cross-contaminating each other is to keep them in total isolation. That doesn't mean 12 separate kitchens, it means food arrives precooked (or whatever the equivalent) and plated in sealed modular packages. Entrees, side dishes, and so forth would be combined in multiple ways according to an a la carte menu, but the food itself is never handled by anyone but the person intended to eat it.

Packaging would need distinctive coding for the biochemistry/species using whatever appropriate colours, patterns, or EM wavelengths apply, and be kept segregated in the food storage and assembly facilities.

At the Table

Here you have two options: strict dining area segregation of customers by species so there's no chance of cross-contaminating between customers sharing a table, or mixed dining with extra precautions. In either case, food packaging won't open unless the compatible species opens it: the table/dining area may give the confirmation, or species-specific biometrics in utensils (for example) might unlock them. Utensils in proximity to incompatible food might set off alarms or trigger packaging to snap shut, if you really want to play it safe.

The packages or table would warm the food in front of the customer.

You may want a rough and tumble tavern, but if food safety is your goal I'm afraid your scifi cantina will have more in common with an automat:

Black and white photo of customer choosing a pie at an early 20th century automat

  • $\begingroup$ In today's current Covid-restricted world, where contamination is now a very big issue, it is not far-fetched to imagine many of these restrictions being put in place here on Earth. Isolation booths for eating are becoming the norm, not the exception. $\endgroup$ Commented Feb 16, 2021 at 2:12
  • $\begingroup$ These are already in place here om Earth. They are called MRE (Meals Ready To Eat), complete with the ability to heat and cook the contents. The packaging would certainly be completely recyclable in some form of 'deconstruction to molecules' method. Mixed species eating at the same table would do so at their own risk, much like gluten-free and vegan diners can intermingle at their own risk with other diners today. They would handle it through mutual conventions, cultural conventions, and such. Really, most fast-food today is pre-prepared in individual proportions and terminally reconstituted. $\endgroup$ Commented Feb 16, 2021 at 2:20


This probably won't work in many stories because of the space and technology that is needed for the wormholes, but since you do have a dozen different alien species, and a space that services them all, this could potentially work. The waiters would write out the orders, and send them through the wormhole, and kind of like in Rek's answer, the food would arrive precooked, but the chefs making the different kinds of food would be in completely different worlds, thus eliminating the problem of cross-contamination.

To avoid the customers eating harmful, possibly lethal food, the owners of the cantina should do careful (fictional) research on what foods harm each species and then the waiters/servers should warn the creatures what is and is not safe.

And to avoid air contamination, if there is a food that one species enjoys eating, but is potentially poisonous or lethal to another species, there should be a few small, sealed, dining areas where that food is eaten. You could also possibly charge a premium on such foods, to discourage species from eating them.


Would it be reasonable to assume that in this era the collective of co-mingling species are aware of these food based threats and long ago each species devised what could more or less be compared to something like a smart watch or some other common place device that does a wealth of things, one of which is food scanning and possibly even threat neutralization?

You could borrow concepts from stories like back to the future where even the basics of food preparation have gone to the wayside in favor of convenience and scientific progress. Like putting a pill in a box and in 10 seconds a masterpiece pizza comes out. What's to say your tavern isn't equipped with an impressive culinary prep station that isolates the process for each species and the entire preparation process is handled by the ovens that convert a collection of cubes into ideally designed foods? And even passed through a contamination screen before reaching the guests?

Since everything has its flaws, it could all be justified with a simple sign on the door that warns guests to make sure they use their decontamination apps, and a wall of text explaining the legal reasons why you cant sue the tavern if you happen to get sick.

Ultimately, you may benefit from the typical Star Trek way of explaining things - you just don't. "Somehow" these machines and practices work, and thankfully, we have gone 7,886 universal years since someone last got sick from the food. Understanding that if you get too specific, you may lose your own argument to someone pointing out the flaws in the science. Can't do that if you don't explain the hows and the whys.


Fake Food

Depending on your technology, you could mimc Star Trek's replicators. Replicated food is not the real thing. It looks real. It tastes real. It has the right texture. But it everything is built from raw stores of carbon, oxygen, etc. on demand. It is more nutritionally balanced than the real thing and is also hypoallergenic so any (organic) species can safely eat it.

Maybe you don't have machines that build food from the ground up. Maybe you have a plant that is safe and nutritious for all species, and you use special hypoallergenic flavorings to make it taste right.

Or if your setting allows for independent neural interfaces, maybe it a computer projects to flavor and texture sensations into the diner's head, so that they eat the flavorless, safe planet, and feel like they are eating steak. Or chocolate. Or deep fried grathnak sausage with a side of bananas (which between the two foods would kill any species but ninety percent of everyone loves the flavors together, even if they normally hate grathnak sausages and bananas on their own).

  • $\begingroup$ To be nutritionally balanced, you're going to need complex macromolecules. Even on earth, one species' favourite complex macromolecule is another's deadly toxin. There's no way around this basic chemical problem. Even with nutritionally void foods, the colourings and flavourings required to make them palatable (and hopefully appealing!) are likely to have compatibility risks. What you're left with is some kind of indigestible polymer for the solids and water for the liquids, and if you can't leave fed or drunk, you've gotta ask why people are going to visit in the first place... $\endgroup$ Commented Feb 18, 2021 at 14:05

I am thinking of the solution posited by Star Trek. Replicators.

Replicators, in use since the early 24th century, are most commonly used as food dispensers aboard Federation starships. The menu is only limited by the programming, as opposed to the days of carrying natural or reconstituted foodstuffs with delivery by special turbolifts or transporters.

Okay, it would not be gourmet food, but it would be pub fare.

The food dispenser replicators would be in completely contained cubicles, that would be sanitized after every meal was dispensed - or at least after every species had been served. Multiple clients of the same species could probably order all at the same time, in the same cubicle. It would be strictly buffet, or cafeteria, style.

The flexibility of this method would allow for accommodating species that pass through very infrequently.

I could foresee the need for completely enclosed serving 'boxes' that would be used between the replicator and the table. Maybe go all out and enclose the trays in a force field. In fact, enclose the booths in some form of force field, that could have a privacy mode for squeamish eaters. When the customer leaves, the entire force field is collapsed, bundling up all of the leftovers, serving dishes, and remnants of bodily fluids into a sealed package that goes straight into the recycler.


Eating food that is not intended for your species can be BAD for you.

And nothing as simple as mere nutrient deficiencies.

A malformed protein is a deadly poison.
A sugar or protein of the wrong chirality is at best and inert clog, at worst also a deadly poison.

Caustic Chemicals: Some species might use Sodium Chloride Crystals as a condiment (like humans) some species might use Sodium Chloride Crystals as a death-row execution substance (like garden snails).

Temperature: Some species might need to eat their food at 35 Celsius for optimal taste. Other species might eat their food at 35 Kelvin for maximum nutrition. OK, OP specifies all are carbon&water based oxygen breathers, so maybe not that extreme.

Each species will need to specify their type explicitly, when ordering. For a small variety as per OP, species name should suffice.
For a place catering to a great many possible species, a codified system that describes the species' needs are indicated.
For example: in Larry Niven's Draco Tavern the species code for both Earth Humans (erect bilateral symmetric endoskeletal primates) and the Chirpsithra (Mantis-like insectiod immortal exoskeletal sages) is "Tee tee hatch nex ool". Just because these two look different does not mean that they have incompatible biochemistry :)

However, people are idiots. One assumes this is true even for people that are not people as we are used to.
So may I also strongly advise a simple food scanner at each table, which analyses both the eater and its meal, and determines at least basic biochemical compatibility. With alarms blaring if/when the eater places a meal with incompatible chemistry on the table?
Of course, one would need to program some exceptions to the device, otherwise it will go blaring each time a Human orders a nice Brandy.

Also, Some very good extraction and filtering ventilators would be a good idea. After all who wants to sit next to a Klingon, who is chasing his live Gagh all over the table? Or who want to sit downwind from that Finnish Human enjoying his Lutefisk, or the Japanese snarfing down a load of Natto(which while tasty and nutritious has an odor which is best described as 'rancid gym socks')?

The same theme is encountered in many SciFi universes:
Larry Niven's Draco Tavern as mentioned above,
James White's Sector General series,
Calahan's Crosstime Saloon,
and even Douglas Adams' Reataurant At The End Of The Universe (ina very tongue in cheek sort of way!)


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