Cooling System Failure on Alfie Amayo — Operations Portfolio

Discovery Timeline

Mon, 01 Jan 0001 00:00:00 +0000

Cooling System Failure / Discovery Timeline

Before the Run

Two runs preceded Batch 50 and shaped how I interpreted the outcome. Batches 48 and 49 were both Orange Liqueur, each running for 7.5 hours and passed quality control (QC) without issue.

During those runs, I observed that the 2000L still ran hotter than the 300L legacy still, with distillate output temperature progressing from cool to warm to hot. The observation was tactile, not instrumented. I noted it but did not return to review it because both batches passed QC and matched the expected flavour.

Impact and Response

Mon, 01 Jan 0001 00:00:00 +0000

Cooling System Failure / Impact and Response

Quarantined

1 batch

Batch 50 — never shipped

Potential radius

5 batches

Stopped before Batch 51

Customer exposure

Zero

Contained pre-bottling

Response time

Same day

Last reversible point

Affected Batch

One batch was affected. Batch 50, a Seekers Mekong Dry Gin run produced on the 2000L still on 29 May 2023, failed QC and was quarantined. It never shipped. Post-incident analysis later confirmed a temperature drift of 1–2°C/hr, rising by approximately 24°C across the 12-hour run.

Root Cause Analysis

Mon, 01 Jan 0001 00:00:00 +0000

Cooling System Failure / Root Cause Analysis

Mechanism of Failure

The 2000L still was connected to a cooling reservoir designed for the 300L legacy still. Under sustained load, heat returned to the reservoir faster than it could be dissipated. Temperature increased at approximately 1–2°C/hr, rising from around 30°C → 54°C over 12 hours.

As coolant temperature rose, the system became less effective at condensing vapour back into liquid. More vapour passed through without being properly captured. Distillate output temperature increased, less intended flavour was retained, and the final profile no longer matched the expected standard.

Structural Improvements

Mon, 01 Jan 0001 00:00:00 +0000

Cooling System Failure / Structural Improvements

Four changes followed the incident. Each was designed to close a specific failure mode exposed by the investigation.

Detection

Change 1

Coolant reservoir temperature instrumented and monitored

A 50°C threshold is now used for coolant reservoir temperature across all batches. It was set from the highest recorded temperature on the 300L still, which consistently produces spirit that passes quality control. Above that level, cooling becomes less effective and product quality begins to drop. Any breach now triggers immediate investigation while the batch is still active, including checking reservoir temperature and confirming the chiller is operating as expected.

Decision Constraints

Change 2

Hard stop on weak signals before raw material commitment

Any weak signal, sensory or operational, is now enough to halt production before raw materials enter the still. Once added, the batch is committed and cannot be recovered. The stop is now a fixed rule, not a judgement call. This delays irreversible commitments until the issue is understood, while action is still possible.

Change 3

Explicit escalation trigger for threshold breaches

One person still has authority to halt production, but the trigger for review is now fixed rather than decided in the moment. Any threshold breach requires a documented review before the run continues. When one person both sees the signal and makes the decision, weak signals are easier to dismiss. The documented review removes that reliance.

Execution Controls

Change 4

SOP versioning with explicit update loop

When a batch requires a workaround or exposes ambiguity, the SOP is updated before the next batch and the previous version is archived. During the incident, key assumptions, including the belief that visible condensation was a reliable quality signal, were being held in memory rather than written down. SOP versioning records these changes and reduces the risk of reverting to outdated practice.

Systems Context

Mon, 01 Jan 0001 00:00:00 +0000

Cooling System Failure / Systems Context

Operations Overview

Seekers Spirits is a craft distillery in Phnom Penh, Cambodia. At the time of this incident, production ran on two stills: a 300L legacy still and a 2000L still installed in early 2023. The 300L still had a stable, established operating pattern. The 2000L still handled larger runs, but its cooling system depended on a reservoir originally sized for the smaller equipment. I owned quality control end-to-end, from tasting through to final release decisions.