Three bannocks, round bread-like discs about 10cm in diameter, dotted with raising. They're sitting on greaseproof paper with a fork for scale.

Fandabi Bannocks – The “Several Years” Claim

It’s been a while – about two years since my last post, but that’s quite handy, as it’s a good point to revisit the Fandabi Bannock experiment. For those unfamiliar, Tom Langhorne, AKA Fandabi Dozi,, who does ~17th Century Scottish survival videos and the like, came up with his own attempt at a survival ration that would keep you going through long days in the hills, survive a long time in storage, and be at least reasonably palatable.

See my previous post for the details, but a brief summary: I made some, they’re not the most delicious thing ever, but perfectly edible, and definitely fill you up. Then I took a few, tied them up in greaseproof paper, and left them on a shelf in my home workshop. Unrefrigerated. For two years. I’ll let Tom explain a the end of his video.

So long story short, are they still edible? I’m not eating them, I’m not that committed, but I do have access to petri dishes and nutrient agar for growing microbes.

First, a few microbiology notes: the setup I’m using specifically avoids growing most human pathogens, including most of the main culprits in food poisoning. Not taking that risk in my own home, not trained to that level anyway. But it does allow us to get a rough idea of how hospitable the bannocks are to other microorganisms.

Unwrapping the bannocks there was no obvious sign on mould or bacterial growth. Nothing visual, no smell, nothing had gone soggy, squishy or otherwise icky. And they were still solid enough to use as a defensive projectile at a push.

Three bannocks, round bread-like discs about 10cm in diameter, dotted with raising. They're sitting on greaseproof paper with a fork for scale.
Fork for scale.

I picked one at random and used a sterile cotton bud dipped in sterile water to sample a few points on the exterior. Then I snapped it in half an took a few samples from the inside in the same way. Each was used to inoculate one half of a petri dish containing a standard nutrient agar.

When we do this kind of “environmental sampling” with high school students, testing light switches and phones and the like, we normally incubate the dishes for 48-72 hours and get decent, often very funky results. This though? Almost nothing. I left it a full 5 days just to get a reasonably clear photo.

A petri dish split in two vertically, the left marked "C" is basically clear, the right marked "S" has fuzzy black stuff on it that looks a bit like fingerprints.

This is the exterior sample (control left, sample right). I’m pretty sure the black stuff is some sort of mould. Not a particularly heavy growth from the length of time it incubated for though.

This is the interior. Basically nothing. A tiny patch of what appears to be the same mould as the exterior, and moulds do tend to like getting their little tendrils all up in stuff.

So the obvious question: would I eat it? At the moment, no, because I’m on holiday and would like to enjoy it without getting the squits from an experiment I’m not being paid for!

But more generally, if I was out in the hills and knackered and 24 hours from anywhere, probably. It’s mostly dry carbs and solid fat, plus some dried fruit sugars, there’s very little that a harmful microbe is going to get excited about. They’ve been stored aerobically (i.e. oxygen can get in) which tends to inhibit some of the nastier ones like botulism. Moulds and fungus can still mess up your day (see ergot for example, common on rye in damp conditions, and having an effect like an unpleasant version of LSD), so I’m not saying this is safe by any means…but it’s not obviously dodgy from this very limited bit of microbiology.

You’d definitely be at greater risk if you licked a random mobile phone all over.

[POSTSCRIPT: Oddly, a few minutes after posting this, I glanced at my YouTube feed to find a short on just how much ergot can mess you up. That’s not what I found, but it’s a salutory lesson to never trust a fungus unless you’re sure.]

Fandabi Bannocks – 2 Months

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For those that haven’t read the earlier post, I tried making Tom Langhorne’s guess at the ideal 16th century Highland survival ration, the idea being to test his reasonable claim that they would stay good to eat, unrefrigerated, for months or years.

And a little over two month in, we’re doing some microbiology stuff at work and I have a spare agar plate for growing a broad range of microorganisms, so I’ve taken a swab from both the outside and the inside of one of the bannocks, which have been sitting on a shelf at room temperature, wrapped in baking paper and tied with string.

The top half is from the outside of the bannock, the bottom half is from the inside, where I broke a chunk off about the side of a standard 2×4 Lego brick. This has had a week to grow at room temperature. When we take general environmental swabs (light switches, phones, doorhandles and so on) we normally get very obvious results in a few days, but I left this one going longer as there wasn’t much.

The big fuzzy splotch near the bottom is probably some kind of mould, likely the kind of thing you find on bread or cheese that’s starting to go off. The neat little round circles are probably streptococcus or staphylococcus, bacteria commonly found on human skin or in the mouth and throat. They may be there because I contaminated the plate while swabbing it, I didn’t do it in proper lab conditions….or they may have been on the bannock as a result of me handling them two months ago.

But long story short, this is a far lower level of microorganisms than I’d expect to see from a similar experiment with, say, a computer keyboard. And people touch those the whole time, then eat a sandwich with their hands, and don’t get food poisoning. So far, so good, as far as edibility goes?

Disclaimer: I’m not a microbiologist. This experiment isn’t set up to look for specific food-poisoning pathogens (in fact it’s designed to avoid growing them for safety reasons), but it should pick up any large growth of generic bacteria, along with the usual collection of spores, moulds and fungus…

Don’t try this at home unless you want to suffer any gastric consequences.

My First Tardigrade

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Every time we do the “Life In The Littlest Loch” experiment with S2 I have a quick look at the water sample I’ve taken to see if I can find a tardigrade, because they’re the coolest little animals ever, and today I found one for the first time! It was in some of the moss on the concrete in front of the school

Tardigrades, also known as “Water Bears” or “Moss Piglets” are about half a millimetre long (they’d look like a speck of dust to the naked eye), and they’re about as close to invincible as any animal gets. They’ll survive very high and low temperatures (150C, oven temperatures, down to -273C, near absolute zero), high and low pressures (from 6x what you find in the deepest ocean, to the vacuum of outer space), and radiation doses hundreds of times higher than those that would kill a human.
They can intentionally dehydrate themselves, meaning that they “mummify” and can go for more than 30 years without food or water, but then wake up again when conditions seem better.

Because they’re so tough they’re found almost everywhere in the world, from hot springs to miles under the ice in Antarctica. In 2007 some dehydrated tardigrades were sent into space on the FOTON-M3 mission, exposed to outer space for TEN DAYS, returned to Earth, and when rehydrated just carried on munching away at stuff like nothing had happened!

Project Fish: Ullapool Freshwater Edition

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Julia’s “Fishing For Footage” project has attracted some funding that took us over to Ullapool for a couple of days to meet up with the young folk at Ullapool Youth Space and chat to them about what we’ve been doing, let them have a look at the kit we’ve developed, check out the footage, and most importantly have a go with it themselves.

Now, when it comes to deep water and young people and funded projects you have to be careful, taking them anywhere near the sea requires a lot of expertise and risk management that we frankly don’t have. But we’d scoped out the local river, which is mostly too shallow to drown in unless you make a real effort.

Not only that, but the kids knew of a spot just upstream from where they normally swim (yeah, they can swim there for fun, but not for our project without paperwork!) where we could drop The Fish in from a bridge and just let it play with the current, the results were lovely. The river is quite peaty, meaning there’s a red tinge to the water, it really makes the green of the plant life pop on video.

The following is raw footage filmed by the young folk who took charge.

Fandabi Bannocks: How long will Scottish-style survival rations be good to eat?

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This is all based around an excellent video by Fandabi Dosi, aka Tom Langhorne, who specialises in actually living the survival techniques and equipment of Scotland in the 16th Century or so. Multiple uses of the plaid (“the great kilt”), starting fires in a notoriously wet country, that sort of thing.

This particular video is about his take on a Highland survival food. He comes up with his own recipe, which as far as I’m aware doesn’t actually exist historically, but it could well have done, or at least a close variant.

So I tried it…and yeah, it pretty much works as advertised. It isn’t, as he points out, going to win any baking awards, but it’s calorifically dense (my sums say about 1,000 calories a biscuit, so three biscuits a day is a reasonable claim), and they’re definitely edible. More than that, they are one of these foods that feel calorie dense when you’re eating them, if I was massively hungry in the hills this would be a very welcome snack. Not as good as firing the stove up and cooking something substantial, but easily enough to fill me up a bit.

But about that shelf life claim – how long will these things stay edible without refrigeration? Given the ingredients I’m willing to bet on months, and wouldn’t be surprised if it was into the years. Not necessarily “best before”, I can imagine they’ll continue to dry out and may get a little more challenging to eat, maybe needing a soak in water first, as with hard tack / ship’s biscuit, but I’m looking more at the bacterial side: will they be safe to eat, rather than pleasant.

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So I cooked some up, have them stored in a cool (not refrigerated) dry place, wrapped in greaseproof paper tied with string (the modern equivalent of Tom’s beeswax impregnated cloth), and I’m going to take a bacterial swab every six months, both from the surface and from the inside of a broken open biscuit, and I’ll see what I can get to grow on an agar plate.

Note for the microbiologists: this isn’t entirely rigorous. I’ll be using standard nutrient agar in aerobic conditions, because that’s the limit of my training and the kit I have access to.

Note for the non-microbiologists: the stuff I’ll be using to grow any bacteria I find is not set up to favour stuff that is particularly harmful to humans, specifically anaerobic food poisoning stuff like botulism. This is entirely on purpose, I’m not trained to mess with stuff like that.

What I’ll be looking at is whether bacteria grow on them more generally. I’ll also be able to pick up moulds and fungi etc, which may or may not be harmful if eaten. See, for example, the blue mould found in many cheeses, and is entirely harmless. Or ergot, a fungus that grows in rye and has similar effects to LSD, but in a far more unpleasant way.

All Sky Camera Update

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In 2020 I started a new job as a science technician in a school. A few months later the UK went into a coronavirus lockdown and I was told to do my job from home…which was an interesting challenge. We’d all seen it coming, so I’d already filled my home workshop with two carloads of broken equipment and antique science stuff in need of a polish, but it didn’t quite fill the time. So I started looking around for funding opportunities for…well, anything.

The Institute of Physics was offering grants for £800 for anything not-curriculum related and ideally relevant to the local area, and we’ve got a fairly dark sky, even from the roof of the school, and an all sky camera costs about £800…so I applied and they sent us some money. All Sky Optics, who supply this kind of thing, were hugely helpful both supplying the right bits and with lots of advice.

It’s been up there for three years now (it took a while to build as a project with students), without a break, in all weathers, taking hundreds of long exposure photographs each night, and then automatically stitching them together into videos each morning, all run by a Raspberry Pi and an astronomical camera.

The last service – we take it down once a year to check on it and add improvements, like the fan to reduce condensation and help the camera stay cool.

As the name implies, it films (nearly) the whole sky with an ultra-wide angle lens, like an extreme fish-eye. The centre of the image is directly overhead, and the circumference of the circular image is the horizon. We’ve caught noctilucent couds, meteors, satellites including the international space station, the milky way slowly rotating, and quite a lot of seagulls. And the aurora. From our location it’s a reasonably regular thing, and wow, did it kick off last week. We normally get a green arc and some pillars on the northern horizon, but this one was directly overhead, with a lot of red in it.

The Class Of ’24

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Oh. Some of you found this blog. Oh well.

So first bit of advice as you all go out into the big, bad, good, boring, fascinating world: if you have a blog, assume your 6th years will find it.

Not only that, assume everything you do online will be found by your friends, family, employers, prospective employers, that cute person from last Friday….the internet is as public as it gets, even things that claim to be private. (Hey, if you were a hacker, would you concentrate on the public stuff or the stuff that claims to be private?)

Other bits of advice: Learn to cook, it makes life cheaper and more fun. Always have an order-of-magnitude estimate in your head before doing the sums, it catches the easy mistakes. Google “Wheaton’s Law”, “Godwin’s Law” and “The Ballmer Peak”. Be generous with minstrels – yes, both the chocolates and the buskers. Anything is fixable, some things are not worth fixing, telling the difference is a major skill. If the folk on the spaceship had listened to Ripley and followed the quarantine protocol, Alien would have been a much shorter film. Do not stare into the laser with your remaining eye. Never leave your wing man (/woman/person….the original quote is “man”). RTFM.

My images of the year (the abstract blocks-of-colour one is MM’s photosynthesis project, shot through the various coloured filters being used, the prism is from WH’s spectroscopy project, when it was just sat out on a bench catching a few more wavelengths than just Neon’s:

A fractal-esque pattern of residue on filter paper, dark brown on off-white.

Fractal Filters

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There’s some chemicals, even in a high school setting, that you can’t just pour down the sink. Some you have to neutralise, some you have to filter…some you have to neutralise to produce a precipitate, and then filter that.

These are in the latter camp. I noticed after leaving a particularly sludgy iron chloride suspension over a weekend that the precipitate in the filter paper had dried in a pretty fractal pattern, the larger surface area at the top of the filter paper and capillary action leading to a gradient of drying and cracking. I’ve been slightly more careful with further disposal methods, trying to find pretty examples.

She’s More Accurately Kerosene

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I’ve been on a big The Interrupters kick recently, a fabulously tight punk/ska band who have instantly become one of my favourites.

But…one of their big tracks is She’s Kerosene, which got lodged in my head while I was working with kerosene. The big problem is the first two lines:

I’m a match, she’s kerosene,
You know she’s gonna burn down everything

I’d been trying to set petroleum fractions on fire, a millilitre or two at a time. They come in mixtures according to boiling point, the lighter ones are similar to petrol and will just ignite, but get towards the kerosene-heavy ones, or kerosene itself, and when you throw a match in…it just puts out the match.

Obviously, it still has those warning signs for a reason, dump a bunch of heat in, say a blowtorch, and you may have a problem. Create an aerosol or heat it up and yeah, it’ll burn. The vapour form is definitely dangerous, anything between 0.7% and 5% atmospheric concentration is explosive. That’s why it’s called, aside from kerosene or paraffin, “jet fuel”. It’s really good at dumping energy under extreme temperatures or pressures, and damn safe compared to gasoline. You want that in a jet plane.

But throw an match into a bucket of kerosene and you get a slight fizzle as the match is extinguished.

So to get this earworm out of my head, I’m recording it here. I love you, The Interrupters, but if you play with me you’re playing with pedantry.

I’m a match, she’s kerosene
But she won’t ignite like gasoline
She’s not, all that volatile
Arson with matches probably takes a while
While, while, while, woah
Matches might take a while
While, while, while, woah
Matches might take a while

She needs a chemistry refresher,
She won’t ignite at standard temp and pressure
She needs a mist, for this caper
Or a five percent atmospheric vapour
If she’d run a, trial experiment
She’d have used a faster accelerant
But now she, must admit defeat
Cos she forgot to read the hazard sheet
Matches, out of action, should have used
A lighter crude oil fraction
She’s not, all that volatile
Arson with matches probably takes a while
While, while, while, woah
Matches may take a while
While, while, while, woah

You play with me…you’re playing with pedantry…
You play with me…you’re playing with pedantry…

[repeat to fade]

Project Fish: Clachtoll Jellyfish Bloom

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We took The Fish (need to find a better name?) over to Clachtoll on the west coast of the northern Highlands of Scotland to see what was under the surface. Good timing, it turns out, as a jellyfish bloom was going on. When conditions are right jellyfish reproduce in huge numbers all over Scotland, sometimes even resulting in issues for nuclear power stations!

Project Fish is the “engineering arm” of Fishing For Footage by Julia McGhee. (I use the term “engineering” loosely, especially in this context!)