Wednesday, October 22, 2014

Starting Point for Setting an Espresso Grinder?

At 1st-line Equipment, we get this question at least once a week. This is a very difficult question to answer as there are several factors that come into play.

Ascaso I-Steel Stepless Doserless Espresso Coffee Grinders
Ascaso I-Steel Stepless Doserless
Espresso Coffee Grinder
Coffee Grinders Design and Manufacture

Most European made espresso coffee grinders are hand assembled in a production line. There can be differences in the grind fineness from two different grinders produced in the same production lot.

The biggest challenge are the grinders that have the numbered settings sticker-ed onto the bean hopper or the top burr plate. When the stickers are placed, they may not be placed in the same exact spot during production.

These small difference in manufacturing can impact the choice of grind fineness setting on a grinder.

Coffee Beans

Coffee is grown on trees and usually harvested twice a calendar year. Typically, two coffee beans grown in a cherry. When there is only one larger bean, it is called a peaberry. The beans are extracted from the cherries which go through a milling process. Beans can be washed, semi-washed, or not washed.

Coffee beans can have different levels of water content, different hardness levels, and different absorption rates. And, these factors can change from harvest to harvest and year to year as environmental factors, such as sunlight, rain, ground moisture, pests, and temperature in each season.

In other cases, some manufacturers sometimes set the grind adjustment too fine and less often, they have it set too coarse.

These changes in the coffee farming life cycle can impact the choice of grind fineness setting on a grinder. Changing coffee blends will typically require an adjustment as well.

Blends and Commercial Coffee Roasters

There are thousands of different coffee and espresso blends roasted by thousands of coffee roasters globally. Each blend of coffee is typically made up of different beans from different countries, different regions within those countries, and many times from different farms within a region.

Master roasters try to balance the blend of beans from the different beans by changing the percentages of each bean. When there is a shortage of a particular bean or to lower costs, a substitute is found.

Hence, Master Roasters can change the makeup of the blend to achieve the flavor profile they are trying repeat from batch to batch.

These changes in the actual bean blend profile can impact the choice of grind fineness setting on a grinder.

Local Environment

So, you are ready to go and starting grinding your coffee. Where do you start? Typically, on a European espresso coffee grinder, the starting point is typically where the manufacturer sets it upon arrival. Then there are fine tune adjustments that need to be made based on the extraction timing, look of pour, and most importantly, the flavor profile and mouth feel of the espresso.

Most clients tend to set it and forget it on the grinder's fineness setting. For regular brew, press pot, or vacpot coffee brewing methods, one can get away with this. However, for espresso extractions, one typically needs to change settings daily or the minimum weekly on the espresso grinder. It is a good idea to keep the following in mind:

a) the oils in the bean tend to absorb to the center of the bean as the beans age. Therefore, the grinder needs to be set slightly finer as the beans age.

b) Humidity and ambient temperature can also factor into the quality of the espresso extraction. We normally receive calls and emails during seasonal changes.

As one can imagine, even with the manufacturer's setting, adjustments to the grind settings are a certainty with any coffee grinder.

Wednesday, October 15, 2014

Brew Pressure Gauges on Espresso Machines

Today, we figured out why espresso machine manufacturers were delaying the installation of brew pressure gauges on home model espresso machines. They wanted less support calls and less inquiries.

The brew pressure gauge is a wonderful tool for diagnosis of a failing pump/blockage internally or for when a customer has a an issue with the espresso extraction. However, it is not a requirement to pull a fantastic espresso extraction.

More specifically, the brew presure gauge will indicate if you need to create more resistance in the puck - the coffee that is in the filter basket. The resistance is created by the amount of ground coffee is in the basket, the grind fineness, and the tamping pressure. When the gauge's pressure is too low, one needs to increase the amount of ground coffee, the tamping pressure, and/or the fineness of the grinds (finer). If the brew pressure is too high, then these need to be lessened.

Without a brew pressure gauge, it is easy. Just look at the pour and time the extraction. Yes, a wasted show, but it would have been wasted anyway even with a brew pressure gauge on the espresso machine.

So, whats the problem with the gauge? The problem is that users read the gauge when not making espresso. Inquiries come in that that the gauge does not go to zero when the espresso machine is at standstill or there is pressure showing when the machine is powered off.

The brew pressure gauge should only be viewed when extracting espresso! It has no meaning when the machine is idle. On a tank model machine, it can measure the pressure of the water internally in the pipe between the pump and grouphead or even somewhere else in the line. Therefore, it is possible to have a reading on the gauge when the espresso machine is idle or powered off. On most direct plumbed espresso machines (those hooked up directly to the water line), it can show the water line pressure.

The other reason for the delay was that limescale can clog the capilary tube that runs from the connection to the rear of the brew pressure gauge. This is just another part that can go faulty.

So, many espresso machine manufacturers were smart to delay the implementation of the brew pressure gauge on home model espresso machines. However, competition in the market has made it more widespread across machines. Hence, the number of inquiries about the reading of the gauge while the espresso machine is idle has also increased. Therefore, please spread the word! And, visit!