The Secrets of Berries

The Mindletter first posted on 26/09/2025. Written by Dr Kitty Wheater

Dear all,

The drop-ins continue Monday and Friday this coming week, and I'm looking forward to seeing some of you this afternoon for the mindfulness community class.

On October 10th-11th, 10am-4pm, Harriet Harris and Francesca Pagni are offering a two-day programme in the Chaplaincy on Responding to Uncertainty and Conflict: a spiritual deep dive using the springboards of Abundant Academy and Lewis Deep Democracy. More info and booking here.

For this week's MindLetter, I'm wrapped up warm, with blackberry-stained hands...

Rowan Berrys growing on a tree

The Secrets of Berries

Autumn is here, with a crackle and a crunch and a punch of red in the trees. There is a bite in the morning air, and in my part of Edinburgh it happened quite definitively on Sunday, the day before the autumn equinox. The skies are the kind of blue that promise frozen jaws, given a couple of months; clouds begin to hail warmth. At night, when I look up, the stars blink frostily from their eons apart. Hope, who barely lost last year’s winter coat (except on my carpet), is already prepped. After work, she noses in drifts of fallen leaves from urban hedgerows, and I pick hawthorn berries and rosehips, while there is still light. My freezer is full of rowan berries and crab apples, ready for the pot.

I have never made these jellies before, but I spent last autumn inside, and I am as hungry for the crackling crunching world as a freshly emerged spring bear. I grew up on blackcurrants and gooseberries, and I remember the berry-picking in Laura Ingalls Wilder, the blackberries and salmonberries for pies and preserves, as something very close to home. My dog then was a German Shepherd, not an American bulldog, but I felt Laura-like, crouching by the gooseberry bush with sore fingers. In a season of red and orange and yellow, our foraging brains seek out bright colours, want to bring them home, to lay down stocks for the winter to come. The abundance of damsons in August and figs dripping from friends’ trees already feels past. That chill in the air, and those scuffling birds, say scarcer times are on the way.

It was a different berry that caught my attention last week, while re-reading geobiologist and geochemist Hope Jahren’s compelling memoir, Lab Girl. A plant scientist with a difference, Jahren is a recurring pick for PhD Book Club, with her evocative depictions of lab work, the beauty of plants, and the frustrations and personal costs of being female in science. Jahren’s berry of choice is the hackberry, which is found throughout North America. ‘Not much can kill a hackberry tree,’ she writes, ‘common as vanilla icecream and similarly uninspiring in appearance.’ But the berry, which looks like a cranberry, has hidden layers: beneath its sweet exterior it is more rock than berry, a geological fortress engineered to protect its progeny for tens of thousands of years to come. Its endurance across millennia means that its fossils generously litter archaeological digs. Locked within them, Jahren thought, could be evidence of chemical reactions that would tell us the temperatures of summers hundreds of thousands of years gone by. The humble hackberry is a climate science hack.

In science you must start with the basics, so Jahren takes lively latter-day hackberry samples from trees in Minnesota and South Dakota and puts them to work in an x-ray diffraction laboratory. Her task is simple: to discover what the hackberry is made of. Find that, and you can measure how and at what temperature it was laid down. Alone in the x-ray lab at midnight, with a three-quarter-inch wrench in her back pocket, it’s not the creepy post-doc that materialises but rather the hackberry’s secret. The stony pit is held together by a white honeycomb-like lattice – and the lattice is made of opal. The hackberry tree protects its seed with precious stone.

To Jahren, it was on this day that she became a scientist. The x-ray readout was unambiguous; it was something that had not been known before, and now was. But more importantly, in this moment, it was known to her. ‘I was the only person in an infinite exploding universe who knew that this powder was made of opal. In a wide, wide world, full of unimaginable numbers of people, I was – in addition to being small and insufficient – special…Until I phoned someone, the concrete knowledge that opal was the mineral that fortified each seed on each hackberry tree was mine alone.’

Jahren stands by the window in the lab and watches the sun come up. It is an exquisite moment, and also, she says, ‘one of the loneliest moments of my life.’ She thinks, while she waits, about her mother and her mother’s mother before her, and how in becoming a female scientist, she has become as unlike them as she can ever be. 

Later, she calls a senior colleague who explains that her observation is not really that radical; just a confirmation of what should have been obvious. ‘I listened politely,’ she says. ‘Nothing could alter the overwhelming sweetness of briefly holding a small secret that the universe had earmarked just for me.’

My first spoonful of elderberry syrup is like that. It’s jaw-droppingly good, an earthy sweet soft tang suffused with cinnamon and ginger. I want to tell someone and I also don’t. It’s enough just to stand in my kitchen and lick the spoon and think about the berries, the many, many berries I’d walked past for years and then suddenly seen, and thought to pick and mash through my own x-ray distillation machine, I mean sieve, to produce one perfect, unequivocal jar of inky elderberry syrup, the first of its kind I have ever made. 

In this moment I am not a scientist, but I am incontrovertibly alive. I am tasting the fruit of reaching into the crackling crunchy world, and it is good. ‘I knew instinctively,’ Jahren writes, ‘that if I was worthy of a small secret, I might someday be worthy of a big one.’ Perhaps the temperatures of millennia past; or a tree you plant with fingers sore from picking gooseberries. The things that will sustain us in times to come are already laying down their precious stone.

I wish you your own autumnal secrets this weekend.

Warmly,

Kitty

the front cover of the book "lab girl"