Occasional changes in the weather, may make it necessary to adjust the grind several times per day.
The more humid the weather is, the slower the shot will be.
The humidity in the air may be hard to notice, since it can even be humid when it’s cold out. The additional moisture causes the coffee to pack tighter, and also holds the water in, causing it to take longer to run through the coffee. If the air is drier, it will cause the grinds to repel the water, and the shots will run through faster.
Picture watering a hanging plant that has been neglected. The soil is dry, so when you attempt to water it, the water sits on the top, and then flushes through quickly. That is how the water is going to react to your coffee if it’s environment is dry or if your grind has sat for too long and is dried out.
Now imagine you have a plant that you keep watered very well. When you water it, the water sits on the top, slowly seeps through, and eventually trickles out the bottom. This is how the water is going to react to your coffee if it’s environment is humid. The moisture in the air packs the coffee tighter together, and also holds the water in the grind longer, causing your shots to slow down.
Condition of Burrs
Sharp burrs shave or cut the coffee into even particle sizes. Imagine a sharp knife cutting something nicely. This is how we want our burrs to cut our coffee beans.
Dull burrs smash or crush the coffee causing the coffee to taste burnt and bitter. If the burrs are smashing the coffee, this causes friction, the friction causes heat, and essentially begins the roasting process again, burning the coffee before you even begin pulling your shots. When the burrs smash the coffee, this also creates inconsistent particle sizes. Think of a bucket with both sand and gravel.
Some of the common signs that your burrs are dull and need to be changed are: muddy pucks, inconsistent extraction, difficulty dialing in the timing of your shots, and inconsistent flavor profiles from your shots.
Key Fact: It’s Important for you to know the type of burrs you are running in your grinder. There are three main types: stainless steel, ceramic, or titanium. Stainless steel burrs should be changed every 500 – 600lbs of coffee that are run through the grinder. If you have ceramic burrs, they may last up to four times longer, which would equal 2,000 – 2,400lbs of ground coffee. We use titanium burrs, that may last up to seven times longer, which is equal 3,500 – 4,000lbs of ground coffee.
The Human Factor
The most common error that baristas make happens during the tamping process. The purpose of the tamp is to evenly distribute the appropriate dose of coffee in the basket of the portafilter, as well as to uniformly compress the grinds into a “puck”. When the tamp is uneven, inconsistent, or becomes disturbed it greatly affects the final outcome of the espresso, often leading to under, over, or uneven extraction of the coffee.
- Dose: 14-16 grams
- Distribution: evenly distribute the grinds into the portafilter
- Tamp: even, consistent, and undisturbed (one and done)
- Pour/Extraction:2 oz of finished espresso with a cap of crema (1 oz) within 24 seconds (22-26 seconds) water to coffee contact time – the time begins as soon as the water starts
Things To Consider:
- Keep the portafilters in the grouphead to maintain a consistent temperature
- Pre-grinding can cause great waste. Grind as you go.
- Coffee storage. Coffee should be stored in an airtight container at room temperature away from direct sunlight.
- Roast date. Has the coffee had time to off gas but still within its shelf life.