outreach: the tale of the 13-week-old cheese and pickled egg sandwich

manchester children’s book festival (mcbf) is an annual event run by manchester metropolitan university (mmu) championed by mmu professor and poet laureate, carol anne duffy. every year, we try to shoehorn in some science – particularly microbiology – and we have used children’s or teen novels involving vampires (twilight by stephenie meyer), zombies (warm bodies by isaac marion) and smallpox (code orange by caroline cooney) to deliver messages around hygiene, disease transmission and vaccination.

this year, the guest author was matt brown, writer of compton valance – the most powerful boy in the universe. imagine our pleasure when we found out that the book series was about a boy who nurtured a cheese and pickled egg sandwich in a shoebox for 13(!) weeks. this was an unmissable opportunity to repeat the experiment. however, after compton and his friend sampled it(!!), the sandwich turned out to be magic, conferring time-travelling talents on the brave consumers. this we could not replicate – nor did we try to.

it was an interesting experiment. i had no idea what would happen to a sandwich left for 13 weeks. i was worried that the pickled egg might prove particularly offensive, so i also made a cheese sandwich control. interestingly, the vinegar pickling the egg actually delayed the rot for a couple of weeks. after about 8 weeks, there was a distinctly earthy odour, and by 13 weeks both sandwiches were considerably shrunken, crumbly and brown.

after appropriate risk assessments, we took the 13-week-old sandwiches (sealed in their boxes) to the mcbf family fun day. our message (apart from not eating the sandwich) was about fungi, their importance in deterioration and degradation, and their morphological diversity. we had some prepared slides and sealed plates for examination, alongside some information to take away about fungi, and about hygienic sandwich preparation and storage.

we were very busy! the target audience for the book would, i imagine, be around nine-year-olds. families examined the sandwich, and sniffed the sealed box – from which odour still permeated. there were discussions around whether or not consumption of mouldy food would be undesirable or harmful. children were keen to use the microscopes and parents took away information. finally, as well as joining in with our teaser twitter campaign, matt brown came to see the sandwiches and meet the scientists. that was exciting too!

the science continues: we are identifying the ‘sandwichome’ and screening sandwich isolates for antibiotic production to tie in with and complement the small world initiative (swi) work to find antibiotics in soil. we have also partnered a school as part of the swi, so the work with the sandwich was an interesting and relevant introduction.

who would have guessed, without a glimpse into the future, that so much could be garnered from a time-travelling sandwich?

joanna verran

faculty of science and engineering, manchester metropolitan university, chester street, manchester m1 5gd, uk
[email protected]

further reading

bad bugs book club. www.hsri.mmu.ac.uk/badbugsbookclub.

manchester children’s book festival. www.mcbf.org.uk.

matt brown, writer. http://mattbrownwriter.com/ science-mirroring-art

all last accessed 11 september 2015.