Principal Wet-Spinning Engineer

Type: Full-time, Permanent |
Salary: £48,000 – £62,000 + stock options |
Location: Harwell, Oxfordshire, UK (in person) |
Schedule: Mon–Fri, 37.5 hrs (flexible within 8am–6pm) |
Eligibility: UK work authorisation required

Kalvo Tech is redefining bioprocessing with Prokitein™, our proprietary protein-based biopolymer. This breakthrough material enables edible hollow fibre membranes for a next-generation bioreactor platform designed to produce structured cultivated meat in a single step. Prokitein™ also opens new possibilities in novel foods
, sustainable textiles and advanced materials
. Join us in shaping the future of sustainable biomaterials production.

As our Principal Wet-spinning Engineer, you will own the wet spinning process at the heart of our technology: turning protein-based dope solutions into hollow fibre membranes and other materials that are reproducible, on-spec and scale. You will lead the materials team, define the fibre-spinning strategy, and work directly with the CTO and executive team to translate high-level vision into an actionable process roadmap – start to finish.

This is a high-impact leadership role where the right candidate will not only shape our core technology but also define how Prokitein™ fibres are made  an ambitious engineer or scientist, this role provides a clear path to becoming Head of Materials, with direct influence on product commercialisation, team expansion, and company growth.

Own and optimise our wet spinning process end-to-end:

• Develop protein-based dope formulations (solvents, concentration, additives, rheology) tuned for spinnability and target fibre properties.
• Run and develop the wet spinning platform for hollow fibres and materials: spinneret design and setup, extrusion, coagulation bath chemistry and conditions, take-up, washing and drying.
• Establish the relationship between spinning parameters and fibre outcomes – wall thickness, lumen geometry, porosity, mechanical strength – and use it to hit specifications reliably.
• Select and optimise crosslinking and post-processing strategies (chemical, physical) to tune mechanical properties, membrane morphology and stability.
• Characterise fibres and interpret results: tensile testing, SEM, FTIR, rheometry, porosimetry, permeability, protein assays.
• Lead troubleshooting on spinning defects and process drift, and drive continuous improvement of the line.

Lead the materials team, acting as line manager and technical authority, and setting the standard for how we plan, record and review experimental work. Define and execute the wet spinning and materials strategy, working with the CTO and executive team to align long-term project goals and technical milestones.

Implement quality control processes to ensure fibres are produced on-spec, reproducibly and with full batch traceability. Develop SOPs, risk assessments and protocols for the spinning line and post-processing, for internal R&D and for technology transfer to engineering and external partners. Collaborate with engineering and external partners on spinning rig upgrades, multi-filament and continuous-line scale-up, and integration of our membranes into the bioreactor cartridge.

Run the materials lab: equipment, consumables, health and safety. Remain hands-on, spinning fibres, running experiments, and analysing performance data alongside the team. Why This Role is Exciting

• Real Ownership – You’ll own the wet spinning process behind the company's platform.
• Pioneer Sustainable Bioprocessing – Help develop a first-of-its-kind bioreactor platform that could transform cultivated meat production and unlock new applications for novel food and sustainable textiles.
• Build the Function – Set the standards, build the team, and define how a lab you'll lead for…