ideally you are looking for an extraction time between 25 and 30 seconds. "If the espresso extraction time is seconds your grind is too coarse.... you should adjust your grinder to a finer setting." "If the espresso extraction time is >30 seconds your grind is too fine....
In order to pull the perfect shot of espresso, you are hoping to achieve an extraction time between 25 - 30 seconds.
Espresso basics:
Brewing time for a single or double shot should be 20-30 seconds. We like 25 seconds. Keep your brewer clean. Oily residue will compromise the taste of your espresso.
The Operating Pump Pressure Is Wrong
If your operating pump pressure is set too low, your coffee will dispense too slowly—or sometimes it won't dispense at all. The optimal pressure is considered to be around 7 to 9 bars, so make sure you check the needle on your gauge before brewing to see if the setting is right.
How Do You Fix Underextracted Espresso? If your espresso isn't extracting as much flavor out of your grinds as it should be or you're receiving an uneven extraction, it's most likely because of a slow pull. So, getting a finer grind, brewing a bit longer, and tamping correctly will help to get a proper extraction.
Traditionally, a single shot (solo) of espresso uses 7g of espresso-fine grounds and yields about 30ml of espresso (about 1 liquid ounce).
If you drink one espresso shot (which has about 50-65 mg of caffeine) and your personal caffeine half-life is about five hours, you'll have a pretty negligible amount of caffeine in your system ten hours after ingestion.
For example, a 20-gram dose at 1:2 would yield a 40-gram double espresso. 18 grams in, yields 36 grams out. 25 grams in, 50 grams out etc. Simply multiply your dose by 2.
It takes 10 seconds for an espresso shot to “go bad”. That is, for the heart, body and crema to blend together into a big black bitter mess. If you're drinking espresso straight, it doesn't matter.
The stream of espresso coming out of the portafilter should look something like thick, warm honey. The finished shot should be golden and have a crema thickness of about 1/4" to 1/3".
Typically, modern espresso is brewed around a 1:2 ratio, meaning that if you start with 20g of ground coffee in your basket you should aim for something like 40g of brewed espresso in your cup.
If the coffee comes through too fast, try to grind your coffee finer. If it comes through too slow, grind your coffee a little more coarse and try again. Knock out the coffee biscuit from the portafilter into a knock box. The biscuit should be firm and crisp when it breaks.
After ten seconds, the espresso was full and creamy and it held a good texture until around three minutes, before gradually deteriorating. This demonstrates the fact that as soon as an espresso is served, it begins to thin, giving some credence to the myth, especially for coffee drinkers who enjoy creamier textures.
Each shot of espresso adds approximately the equivalent caffeine of one 12 ounce cup of brewed coffee. Ounce for prepared ounce they are all about the same.
It will have a burnt, ashy flavor and may be less palatable than fresh shots; however, they still contain caffeine. The length of time it takes for a shot to 'die' is debated, ranging from ten seconds to three minutes.
Generally, darker-roasted coffees perform well with a smaller ratio, while lighter-roasted coffees perform better with a larger one. Borrowing language from Italian espresso nomenclature, a 1:1 to a 1:2 is a Ristretto espresso, 1:2 to a 1:3 is a Normale espresso, and a 1:3 to a 1:4 is a Lungo espresso.
Even if you drink coffee in moderation, two shots of espresso may be too much if you're sensitive to caffeine. By ordering one of four espresso shots, you can get more than half the safe amount of caffeine per day. According to Coffee Chemistry, one fluid ounce of espresso can contain 30 to 50 mg of caffeine.
Seven shots of espresso is considered too much to drink in a day. The FDA recommends that adults do not exceed 400mg (0.014 oz) of caffeine daily. Espresso contains roughly 63mg (0.002 oz)per serving. Therefore, drinking seven espressos or more will exceed the limit and potentially lead to health issues.
Tamping pressure shouldn't be too hard as it can lead to over-extracting and an extremely bitter taste of espresso. Polish the puck with a twisting motion. Avoid twisting as you push down though. Otherwise, you can ruin the packed coffee.
Apply 20-30 pounds of pressure, and polish
Baristas often recommend 30 pounds of pressure, but some do as little as 20 pounds. More and more are finding that tamping pressure is overrated—it's hard on the wrist and cause an over-extracted, bitter brew. Use a twisting motion as you pull up to “polish” the puck.
Aim for your shot to pull between 25 and 30 seconds. To make this happen, look to your grinder. We'll manipulate the grind size to change how long water flows through the coffee bed. Think of coarse coffee like stones and fine coffee like sand.