Why We Test What We Already Know

  • By Jeremy Amos

Published: Tuesday, Dec 9, 2025

There's a master distiller in Scotland named Jim McEwan.

 

He spent over fifty years making whisky. Started as a cooper's apprentice at fifteen, worked his way up to master distiller, became a legend in the industry.

 

He'd taste thousands of barrels a year. Could tell you the age, the cask type, the potential of a whisky just from nosing it. His palate was so refined that distilleries would fly him around the world for consultation.

 

Here's the interesting part: even after five decades, even with his level of expertise, he never released a batch without testing it.

Every barrel got tasted. Every blend got verified. Every bottling run got checked.

 

When asked why he bothered testing what he already knew, he said something I think about often:

"Because the day I stop testing is the day I start guessing. And guessing is not how you make something that lasts."

Title

What's Important

 

We test every batch that comes through our facility. Not some batches. Not representative samples. Not random spot-checks. Every. Single. Batch.

 

Batch 1,000 gets the same testing protocol as batch 1. The suppliers we've worked with for years get tested the same as the supplier we're trying for the first time. The formulation we've run a hundred times gets the same scrutiny as the new one we're still dialing in.

 

And yes, we know this seems redundant. Expensive. Unnecessary.

 

When people ask us: "You've been working with that hemp supplier for years. The quality is consistent. Why are you still testing every batch?" We tell them it's because the day we stop testing is the day we start guessing. And guessing is not how you make something that lasts.

Title

Never Stop Testing

 

Let me tell you what happens when you stop testing what you already know.

 

It starts small. Reasonable, even. "We've tested the last fifty batches from this supplier. All clean. All on-spec. Why test batch fifty-one? We know it's going to be fine."

 

And batch fifty-one probably is fine. So you skip the test. Save a few hundred dollars. Move faster.

 

Batch fifty-two comes in. Same supplier. Same quality. You skip that test too. Before long, you're not testing consistently anymore. You're testing selectively. When you remember. When you have time. When it feels necessary.

 

That's when things go wrong.

 

Because batch sixty-three - the one you didn't test because you "already knew" it would be clean - that's the batch where something changed.

Different field. Different harvest date. Different environmental conditions. Some variable shifted that you didn't know about because you stopped checking.

 

And now that contaminated batch is in your supply chain. In someone's product. On someone's shelf.

 

All because you stopped testing what you thought you already knew.

Title

Deviance

 

There's a concept in aviation called "normalization of deviance." It's what happens when small departures from standard procedures become normalized over time. You skip a checklist item once. Nothing bad happens. So you skip it again. And again. Eventually, skipping the checklist becomes the new normal.

 

Until the day that checklist item actually matters. And by then, you've forgotten why you had it in the first place.

 

The Challenger space shuttle disaster in 1986? Normalization of deviance. Engineers had seen O-ring erosion on previous flights. They flagged it. But nothing catastrophic happened, so the concern got normalized. Until it didn't.

 

Testing what you already know is how you prevent normalization of deviance.

 

It's how you maintain standards when the pressure is to relax them. When the temptation is to shortcut. When "we already know" starts to sound reasonable.

 

The test isn't just checking the batch. It's checking yourself.

 

It's the proof that you're still operating by principle, not convenience.

Title

What Testing Actually Tests

 

Here's what consistent testing actually tests:

 

It tests your commitment.

Anyone can test when they're uncertain. When it's a new supplier or a questionable batch or something that makes you nervous. Testing what you already know proves you're not testing because you're worried. You're testing because it's the standard. 

 

That's the difference between fear-based quality control and principle-based quality control.

 

It tests your humility.

"We already know" is arrogant. It assumes nothing changes. That variables stay constant. That your knowledge is complete. Testing what you already know says: "We probably know, but we're going to verify anyway. Because we might be wrong."

 

That humility is what catches problems before they become catastrophes.

 

It tests your systems.

If you only test when you're uncertain, your testing becomes reactive. Subjective. Inconsistent. Testing what you already know makes testing systematic. Built into the process. Not dependent on someone's judgment call about whether this particular batch "needs" it.

 

Systems beat judgment. Every time.

 

It tests whether you mean what you say.

We say quality is non-negotiable. That standards don't bend. That every batch gets the same scrutiny. Testing what we already know is how we prove we mean it.

 

Because if we meant it only when convenient, we wouldn't mean it at all.

Title

Test What You Know

 

There's a restaurant in Tokyo called Sukiyabashi Jiro. Three Michelin stars. Run by a sushi chef named Jiro Ono who, at 98 years old, is still working. He's been making sushi for over 75 years. He knows fish better than almost anyone alive.

 

And every morning, he still goes to the fish market. Still examines each piece. Still checks what he already knows. When asked why he bothers after seven decades of expertise, he said:

"The fish changes. The season changes. My hands change. The only way to make perfect sushi is to check everything, every time. Even when you think you know."

 

That's what masters do. They test what they already know.


Not because they doubt their knowledge. But because they respect the craft enough to never assume.

Title

Non-Negotiable

 

Jim McEwan, the master distiller in Scotland, tasted tens of thousands of barrels over his fifty-year career. His palate was legendary. He could identify distilleries blind. He knew whisky better than almost anyone alive. But he never stopped testing. Never assumed. Never released a batch because he "already knew" it would be good.

 

Because making something excellent isn't about what you know. It's about never assuming you know enough to stop checking.

 

That's the philosophy.

 

Test what you already know. Not because you're uncertain. But because certainty without verification is just arrogance with better PR. Standards are only standards if you maintain them when it's inconvenient. When it's expensive. When "we already know" sounds reasonable.

 

Batch 1,000 gets the same test as batch 1.

 

The supplier we trust gets the same scrutiny as the one we don't. The formulation we've run a hundred times gets the same verification as the one we're trying for the first time.

 

Because that's what "non-negotiable" actually means.
 

Not that we maintain standards when it's easy. But that we maintain them especially when we think we don't need to.

Title

What Lasts

 

So yes, we test what we already know. Every batch. Every time.

 

Not because we're uncertain about the result. But because the day we stop testing is the day we start guessing.

 

And guessing is not how you build something that lasts.

Title

Working with a manufacturer? 

 

Ask them: "Do you test every batch, or do you test selectively based on supplier history?" 

 

The answer will tell you everything you need to know about their standards.