By the end of May, after weeks of construction, cleaning, painting and fitting out, our lab was largely ready and the fruiting room was finally able to receive its first test batch of mushroom blocks.
It should have been the moment when the building work gave way to the satisfying part: watching healthy mushrooms emerge.
Instead, the weather became hot during delivery and most of the blocks arrived in poor condition.
To be brutally honest, it was gutting. When you have spent months building a growing space with very little spare money, you want the first crop to reassure you that all the work has been worthwhile. You do not particularly want it to demonstrate the next expensive problem.
Unfortunately, mushrooms are not interested in morale.
A mushroom farm is an environmental-control problem
People naturally focus on humidity when they think about mushroom growing. Humidity matters, of course, but it is only one part of the environment.
Different varieties and stages of growth respond to temperature, fresh-air exchange, carbon-dioxide levels, humidity, light and airflow. These factors also interact. Adding ventilation can change the temperature and humidity. Cooling the room can create condensation. A warm corner of the building may behave differently from the area where a sensor happens to be mounted.
Lion Works is a wonderful home for the farm, but it is also an old industrial building that can get very warm during the day. Our insulated fruiting room protects the crop from some of that variation, but insulation does not magically remove heat. Once warmth gets into the room—from the building, the equipment and the living blocks themselves—it has to go somewhere.
The first delivery made it obvious that dependable cooling was not an optional upgrade to tackle later. If we wanted consistent crops, it had to become part of the basic growing system.
Why we paused instead of pretending everything was fine
We had already proved that we could fruit and supply mushrooms, and part of the next planned crop had customers waiting for it. The tempting response would have been to order more blocks immediately and hope for kinder weather.
There was no point.
Buying more stock before improving the temperature control would simply have put more money and more mushrooms at risk. We therefore took a short pause from shipping while we worked through the cooling problem.
That is not the most exciting update for a young food business to give, but it is the responsible one. Restaurants and farm shops need a supplier that can deliver good quality consistently, not a supplier that produces a brilliant batch when the weather happens to cooperate.
We are trialling several varieties, including Lion’s Mane and different oyster mushrooms, but we only want to offer them more widely once we are confident in the yields and quality. There is a big difference between getting a mushroom to grow once and building a process you can rely on commercially.
Sensors help, but they are not the whole answer
We have installed sensors throughout the growing environment, and my technical background means I am naturally drawn to measurements, monitoring and alarms. Data is extremely useful. It tells us how quickly the room responds, whether conditions are drifting and how changes to airflow or cooling affect the environment over time.
But sensors do not grow mushrooms for you.
They need to be placed sensibly, checked against what is actually happening in the room and interpreted alongside the condition of the blocks and fruiting bodies. A dashboard can say that the average temperature is acceptable while a particular shelf or corner is having a completely different experience.
This is where Charlotte’s practical cultivation experience is so important. Between her knowledge of fungi and my tendency to treat the room like a small data centre with edible outputs, we are gradually building a system that combines observation with evidence.
The useful failure
I would much rather our first test batch had arrived perfectly and produced a heroic crop. It did not. But it exposed a weakness while the farm was still young and while we were in a position to redesign around it.
That is what test batches are for, even if nobody particularly enjoys the lesson at the time.
The experience has changed the way we think about the farm. Temperature control is not simply a machine bolted onto the side of the fruiting room. It affects how we schedule deliveries, how much stock we are prepared to accept, which varieties we trial and how confidently we can make promises to customers.
We will share more as the system develops, including the parts that work and the parts that need another attempt. If you run a restaurant, café or farm shop in Sheffield and would like to discuss future availability or trial samples, please get in touch. We would rather have an honest conversation about what is ready than promise a crop before the growing environment is ready to support it.