Springs

David Jackson

My understanding is that most spring lever machines use two springs, but the Londinium machines only use one. This begs a few questions...

1. Does this significantly reduce the effort required to pull down the lever?

2. Does this reduce the peak pressure applied?

3. What are the resulting advantages in terms of espresso production?

Thanks

David

Reiss Gunson

good morning david

1. yes
2. yes
3. a double spring was introduced to levers when electric pump machines became available to make the taste more like a pump machine, a bit of an inferiority complex perhaps

so if you want the espresso to be flatter and denser in taste, at the expense of layering and detail get a lever espresso machine with two springs. also expect a good number of people to curse it and refuse to use it because of its 'mousetrap' action

on balance it may make more sense to get a pump machine if you want the pump machine taste

kind regards

reiss.

Reiss Gunson

ps - we can supply group tops with twin springs if you like, ive got one right here beside me.

David Jackson

Thanks Reiss

Ok that's very interesting - I'd not realised that the double spring was a later, perhaps unfortunate addition.

I've mostly drunk lever coffee for the past ten years, so I'm not in search of a pump machine taste, not that I'd know exactly how that compares on the same beans, but the pump shots I've had (in cafes) tend towards bright and somewhat aggressive, my home shots more chocolatey. I know which I prefer.

It's always interesting to know the reasoning behind choices that go against the grain, so thanks again.

Reiss Gunson

they also started enclosing the lever groups for a similar reason (to make them look more like pump machines with a fully enclosed aesthetic)

thankfully with time we have come full circle and there is no longer a need to apologise for the lever group

instead it is now mimicked by the industry's most expensive machines in their efforts to use a great deal of complexity to try and mirror the declining temperature and pressure profile of a lever group