La Scala Butterfly Pre-infusion time
I just finished refurbishing a lever operated La Scala Butterfly. She was in pretty bad shape but she's looking good and running well now. I was wondering if anyone had advice on how long the pre-infusion should go for. I've been doing about 30 seconds but I'm not 100% sure if I'm way off or not. If there's any other general advice that would be appreciated as well. I'm relatively new to making coffee and need all the help I can get.
Assuming you mean a lever to run the pump as opposed to a true lever machine? If so I have the same machine, happy to answer any q's although I'm no expert. I use mine every day, for the last 5-10 years.
I don't do any pre-infusion, I'm curious to know where you are basing that from?
I do a cooling flush of the group head if on for more than about 1/2 hour and then unused for more than a few mins. I'm fairly practised at 'patting' the group head to feel the temp to decide if flush required. *Don't rest your hand on it if learning this or you'll learn the hard way!
The LS Butterfly normally has a version of the E61 group, presumeably yours is the "manual lever" operated version ?
Originally Posted by Gemptron
If so, the pre-infusion is preset within the group design at about 3 -5 secs when you FULLY raise the lever and the pump runs.
I suspect you are attempting the "manual" pre-infusion trick of holding the lever mid position without engaging the pump... ??
Whilst that is often suggested, in a correctly set up E61, it would not be possible, as both the brew valve and the PI valve SHOULD remain closed in the mid position.
However, as you obviously realize, it is possible that some groups do allow brew water to flow unpumped if the lever is held "just right"
But... if you are doing this with a tank feed machine, without the pump running, there is only a little gravity flow ( near zero pressure) to provide any water to the puck,...so any attempt a PI will be very unpredictable.
Also ...any pre-infusion longer than 10-15 sec or so , is excessive.
Thanks for the replies,
Yes I do mean the manual lever e61, I had read bits and pieces on the internet that talked about pre-infusion on e61's but I wasn't sure if it applied to my machine. It is a plumbed in machine, however it's not plumbed in just yet - got the hose running into a bucket. Thanks for the help, I guess I won't bother with trying to pre-infuse now.
Traditionally, the lever on an espresso machine (after opening the water valve) either applies the pressure to the water directly, or on a spring which pressurises the water upon release. If the lever operates a pump switch, then it's not really a lever machine. (Sorry!)
The advantage of a true lever is that the extraction pressure can be controlled directly (no spring), or is automatically reduced over the time of the extraction as the spring tension decreases. The pre-infusion is controlled by the decision of the barista who operates the lever.
The Butterfly appears to be a relatively standard machine in its class and is without the additional facilities that would allow manual pre-infusion. (Nice looking machine though. )