Crema begins in the roasting process.

Crema 从烘焙过程开始。

All of this starts in the roasting process.

这一切都始于烘焙过程。

Now, during the roasting process, there are over 1,500 chemical reactions that take place.

在烘焙过程中，会发生超过 1,500 种化学反应。

Now, most of this escapes the coffee bean during the roasting process.

在烘焙过程中，大部分水分会从咖啡豆中流失。

Now, a dark roast will produce a lot more CO2, but the bean can't keep hold of it because that roasting process has made it so much more porous.

深度烘焙会产生更多的二氧化碳，但咖啡豆却无法留住二氧化碳因为烘焙过程让咖啡豆变得多孔。

This is occasionally done by unscrupulous people who know that when you roast a kilo of coffee, you might only get 850 grams out because of loss of moisture and other things during the roasting process.

这种做法偶尔会被一些肆无忌惮的人采用，因为他们知道，当你烘焙一公斤咖啡时，由于水分和其他物质的流失，你可能只得到850克咖啡。

And then we weigh them out and we put them in our roaster and that's when the real magic happens, that's when the color changes and the whole roasting process creates the coffee that we drink.

然后我们将它们称重， 然后将它们放入我们的烘焙机中，这就是真正的魔法发生的时候， 那是颜色发生变化的时候，整个烘焙过程创造出我们喝的咖啡。

They'll age a bit quicker, so they'll degas faster 'cause they're more brittle and that roasting process kind of makes the whole coffee bean more porous and so it does age a little quicker, but fresh it will have more CO2.

它们会老化得更快，也会脱气得更快因为它们更脆烘焙过程会让整个咖啡豆更多孔所以它确实会老化得更快，但新鲜的咖啡豆会有更多的二氧化碳。