Between Brew Protocol: How to Get Consistent Espresso Shots

Between Brew Protocol: How to Get Consistent Espresso Shots

If you’ve ever noticed that a shot from an idle group runs longer than one from a group being used regularly, you’re not imagining it. The reason almost always comes down to temperature—and more specifically, how your coffee machine manages it.

Even the most advanced multi-boiler machines aren’t exempt. In fact, because they’re designed to be so precise, they can actually make temperature fluctuations more noticeable.

The Temperature Story

All espresso boilers operate within a temperature band — a high and a low point that the system cycles between to stay stable. High-end machines tend to keep this band very tight.

When a group sits idle, the system has time to settle perfectly into its target temperature. Everything is calm and stable.

But the moment you start a shot, the machine has to quickly compute how much heat to add to keep the water exactly where it should be. That reaction time can cause tiny over- or under-shoots before the system catches up again.

These variations are small, but espresso is sensitive. Even a slight shift can stretch or shorten a shot. And that’s where Between Brew Protocol (BBP) comes in.

What Is Between Brew Protocol (BBP)?

BBP is simply the routine you follow between each espresso shot.

For example:

  • Flush 20 ml

  • Wait 20 seconds

  • Grind

  • Tamp

  • Pull shot

Your version might look different, and that’s fine. What matters is that you do it the same way, every time.

A consistent BBP puts your machine “in the zone.” It learns how much power to apply and for how long to keep the temperature dead-on. And when temperature is steady, your yield and extraction times stay steady too—shot after shot.

So Why Does an Idle Group Pour Longer?

Because an idle group hasn’t been following your BBP. It’s been sitting at its stable idle temperature, not cycling through your routine. When you wake it up, the temperature response behaves differently—and the shot usually runs a bit longer.

Consistency in the moments between shots is what keeps consistency in the shots.

A Note on Portafilter Rinsing

Many baristas rinse their portafilter between shots thinking it’s a good hygiene step — and it is — but it introduces inconsistency.

Residual water in the basket can mix with old oils stuck beneath and around the base. Once fresh grounds hit that moisture, extraction changes. And because it's nearly impossible to replicate the exact amount of leftover water each time, it becomes a variable you can’t easily control.

If you’re chasing repeatable results, be mindful of how—and when—you rinse.