ASBC Microbiology ex–New Belgium yeast Head Distiller
field checklist // contamination control
The craft brewery & distillery contamination control checklist
Most contamination isn't bad luck — it's a missed step that nobody owns. This is the routine I'd run on your floor, organized so a shift lead can work down it without thinking. Print it, laminate it, hang it by the CIP station.
Built from real production experience, not a textbook: yeast and microbiology work at the ASBC, a Yeast Specialist role at New Belgium, and time as a Head Distiller. Use what fits your process; the goal is a repeatable routine, because contamination thrives on the steps you skip when you're busy.
Every shift
daily
The five-minute habits that catch 80% of problems before they spread.
Sanitizer concentration verified — test, don't eyeball. Log the PPM/strength for each batch of solution made.
Hose ends off the floor — no hose end, racking cane, or wand ever touches a drain, a boot, or standing water.
Sample ports + valves sanitized before and after every draw. They're the most-touched, least-cleaned surfaces you have.
Drains cleaned + treated — the #1 reservoir for wild yeast and bacteria. Foam-clean daily; never spray a drain near open vessels.
Visual + smell check on every fermenter you open: pellicle, ropiness, off-aromas (phenolic, lactic, acetic, butyric). Trust your nose.
Hands + gloves sanitized at each transfer; no jewelry, no touching faces, then product-contact surfaces.
Weekly
weekly
Full CIP on all transfer hoses, pumps, and heat exchangers — disassemble quick-disconnects and inspect gaskets.
Gaskets & O-rings pulled, inspected, swapped if cracked, scored, or stained. The hidden home of infection.
Yeast viability + vitality check before repitch; methylene blue or equivalent. Cap your generations.
Plate or test a sample from each brand — even a simple forcing/turbidity test catches drift early.
Walls, floors, ceilings in the cellar washed down; check for mold at drains and cold spots.
Monthly & periodic
monthly
CIP efficacy verified — swab + ATP or plate post-clean on a rotating vessel. Prove the clean, don't assume it.
Glycol & cooling jackets inspected; condensation and biofilm love jacket exteriors and trub lines.
Packaging line deep clean — filler, capper/seamer, fill tubes. Most DO pickup + late infection starts here.
Spare-parts audit — gaskets, seals, sanitizer stock on hand so a worn part never becomes "we'll do it next week."
Training refresh — one routine, written down, so it survives staff turnover.
Red flags — stop and investigate
act now
Sudden over-attenuation or gravity dropping past terminal — suspect wild yeast / Brettanomyces or Diastaticus.
Pellicle, ropiness, or haze that wasn't designed in — likely Lactobacillus, Pediococcus, or Acetobacter.
Gushing or over-carbonation in package — refermentation; isolate the batch and check your most recent fillings.
Off-aromas: sour where it shouldn't be, "Band-Aid" phenolic, buttery diacetic that won't clean up, vinegar.
Same tank, repeat problem — quarantine it, tear down every fitting, and verify CIP before it's back in rotation.
When in doubt, isolate the batch and the vessel before it cross-contaminates the cellar. One lost batch is cheaper than a house infection.
turn the routine into a system
Want this running on autopilot?
I help craft producers turn checklists like this into living systems — digital logs, automatic reminders, and an AI assistant that flags drift before it becomes a house infection. Fermentation operator who builds the software too.