We all love our coffee. Once you get your freshly roasted beans back home, isn’t it time to enjoy a nice cup? Of course, you do, but you end up with a bad-tasting cup of coffee.
Before we start, remember that coffee needs to degas. What is degassing you ask? In a nutshell, it is the process where freshly roasted coffee beans release gas built up during the roasting process. This is why you don’t brew with beans roasted yesterday as the escaping gas will disrupt your brewing process. You can read more here. Also make sure you aren’t using stale beans. If you buy beans without a roasting date or coffee older than 3 months, don’t expect the flavors to show up. Afterall, coffee is a perishable good.
The first espresso diagnosing or troubleshooting steps would be to check your extraction time and weight. Refer to the guide from your roaster. For Milkyway blend, the recommendation from the roaster is that you dose (or grind into your portafilter) 16.5g of beans to result in around 18g of espresso in 30 seconds.
If you’re getting too much or too little, or if the espresso shot looks like you turned on the tap and it is gushing out, then you will need to make adjustments.
Too Fast Extraction
Your coffee is pouring out means you need to grind finer. Finer ground coffee results in
- A finer grind slows the water flow
- This increases the time taken for the shot, so if you’re getting your shot in 15 seconds, a finer grind will increase that time.
- This allows more water-coffee contact time during the extraction, resulting in more flavors coming out.
Too Slow Extraction
Your coffee is dripping out slowly means you need to grind coarser. The opposite of the above will happen.
- A coarser grind allows more water to flow
- This speeds up the time taken for the shot, so if you’re getting your shot in 80 seconds, a coarser grind will reduce that time.
- This allows less water-coffee contact time.
Remember, change one variable at a time. Changing two variables makes it difficult for your to figure out what is going on at any one time. Usually, we recommend adjusting the grind as the first step. Adjusting the dose (beans ground) is usually my last resort in tuning. Do ensure also your coffee machine is clean and provides adequate pressure. A clogged machine, poor pump pressure or faulty temperature will result in poor coffee flavors.
