Espresso has been finding its way into the homes of coffee lovers more and more over the last 5 years, specifically semi-automatic machines (those that control pressure instead of a manual pull of a leaver). There are many variables to consider when pulling a shot, and these can vary widely depending on the type of coffee you’re using. The following instructions are for a medium roast coffee, we recommend steering clear of dark roast coffee.
Freshly grind 18g of coffee beans in a burr grinder. You need a very fine, consistent grind. How fine you say? Well one easy test you can use at home is to pinch the grinds between your thumb and forefinger. The coffee needs to clump in the center of the pinch, where the pressure is highest, but not too much. If it does not clump at all, it is too coarse and will under extract. If it clumps excessively, it is too fine and will overextract.
Dose 18g of the ground coffee into the group-handle basket, we recommend removing the basket from the group handle. Reinsert the basket into the group handle and remove grounds from the edge of the basket, ensure the dose is level in the basket.
Using a good weighty tamper apply 30lbs of pressure (a firm handshake), ensure your tamp is level. As you push down also twist the tamper to consolidate the grinds further. Alternatively our preferred method at lost sheep is this, Apply 10-15lbs of pressure while rolling the tamper around the inside edge of the basket. This is the ‘around-the-world’ method that consolidates grinds even further and thus needs less pressure. Great when you make hundreds of coffees a day!
Before locking your group handle into your machine, it's best practice to purge the shower head by running water through it briefly. This assures the water in the shower head and pipes is at the correct temperature of 93C. Lock in the group head and immediately place your cup/glass underneath. We love the great acme cups and duralex glasses.
Some coffees benefit from pre-infusion, where others do not. Try both with and without to see what you prefer. To pre-infuse start extraction and stop one second after and wait two seconds before starting the full extraction. After restarting, the extraction should last between 25 and 30 seconds*. You are looking for a 30ml (30g) yield plus a head of hazelnut coloured crema. The flow of espresso from the handle should be smooth and consistent with no hesitation or dripping.
if you find the 30ml extraction is occurring faster than 25 seconds then you need to make your grind finer, equally if you find your 30ml extraction is taking longer than 30 seconds then you need to make your grind more coarse.
* Grinder Settings; coarse = faster / fine = slower.
* Different coffees will need different extraction times. a lighter roast will need longer than a medium, but ultimately it's all about your personal taste, so play around a bit.