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10 Things You Need to Know About Crema

Beginners often ask seniors what crema is.

Some players even asked senior crema why he didn't come out.

Senior, let's sort out the key points about crema for everyone to see today

1. What is crema?

Espresso machine extracts the top layer of oily stuff when espresso coffee (picture 1 top layer)

What is Crema's principle?

Simply put, under the high pressure and high temperature extraction environment, the carbon dioxide in the beans is forced into the coffee oil (Figure 2 shows the oil coating the carbon dioxide)

But the above is a simplified statement. To be more precise, see what Scientist magazine says:

Surfactants form a thin film that surrounds tiny bubbles of carbon dioxide and water vapor. Crema also contains emulsified oils, which contain the main aromatic components

3. Can I cook crema at home?

Only espresso can cook fuller crema, other equipment includes: [hand flush, siphon, French pressure and other household equipment is not cooked]

However, a small number of equipment such as mocha pots with pressure valves and music presses can cook a little crema, but if compared with the crema standard of espresso machines, it is obviously much thinner.

4. Does crema have a big impact on espresso?

Crema in moderation is definitely one of the important criteria for espresso to taste good. On the one hand, crema can coat aromatic gases, so it has an impact on the complexity of aroma; on the other hand, crema will bring a thick and thick taste, which can be said to be the unique feature of espresso.

5. Does espresso with lots of crema mean good?

Crema will appear under the correct espresso machine operation, but [rotten beans can also cook crema, so crema does not mean absolutely delicious], do not believe crema.

In the process of espresso extraction, the extraction time greatly affects the taste, more than 2 seconds of extraction may be completely destroyed, in order to extract a little more crema, it is also very possible to cause mixed taste and bitterness, so too much crema does not mean better taste.

Does Crema have to be red? Other colors mean bad?

Some people think that crema other than Chu red is bad, mainly because [traditional espresso beans are deep baked above], so crema color is darker.

However, at present, many stores use espresso beans with different baking degrees, medium roast and even light roast,[crema presents a lighter golden yellow is normal], does not mean that it is bad or bad espresso.

7. Must be fresh beans to have a lot of crema?

In the case of ultra-deep roasting of beans with traditional espresso, the exhaust volume of beans is extremely large, so the production of crema will be weakened after about 10 days.

However, in terms of the medium-to-dark baking degree that many stores currently prefer, espresso still has a lot of crema after cooking for about 20-30 days, and even the quality of the extract is better.

Is crema the source of aroma? Mocha pot and philharmonic press should pursue crema?

Crema does preserve complex aromas, but only in the context of an espresso machine.

Mocha pot or philharmonic pressure because of insufficient pressure, the extracted crema is very thin and fragile, even if it appears, it dissipates quickly, and the aroma is still floating in the air, so the value of crema is relatively small. And sometimes in order to extract crema to adjust the dosage or grinding degree, out of the cup instead too bitter or destroy the balance, then put the cart before the horse. It is better to trust your tongue than to pursue crema.

9. Is crema related to pulling flowers?

Crema is an absolutely necessary condition for pulling flowers, especially complex patterns need crema with complete structure, but don't forget the above, too much crema does not mean better to drink.

Therefore, it is definitely a high master to have delicious crema with beautiful pull flowers, but it is not a good thing to choose crema but bad beans in order to pull flowers, or to extract too much crema to cause bitter and miscellaneous taste.

10. Does crema last longer mean coffee quality is better?

Crema can be said to be a layer of coffee oil bubbles, which are very easy to dissipate, so it seems meaningless to force him not to dissipate. As long as you don't disperse within a few minutes from the back of the cup to the two mouthfuls in front of you, it is considered a normal product.

The general espresso is originally the drink that should be drunk as soon as possible. First, the amount is small and the temperature drops quickly. Second, the aromatic gas dissipates quickly, so it is recommended to drink it as soon as possible.