In July 2020, I started thinking more about degassing and coffee. I had been experimenting with letting my coffee roasts rest for 3 or 4 weeks before using them, and I noticed an improvement in taste and extraction level. I suspected part of the extraction was due to less carbon dioxide.

2020年7月，我开始更多地考虑脱气和咖啡。我一直在尝试让我的咖啡烘焙器休息3或4周，然后再使用它们，我发现其味道和提取水平有所提高。我怀疑萃取的一部分是由于二氧化碳较少。

So I started an experiment to see if I could degas beans faster using a vacuum jar with the hope of using them sooner. In the process, I started see what research was out there, and I ran across a great paper and video presentation of that research by Samo Smrke and others.

因此，我开始进行实验，看是否可以使用真空罐对豆进行脱气，以期尽快使用。在此过程中，我开始看到在那里进行了哪些研究，并且遇到了萨莫·斯姆克(Samo Smrke)等人的精彩论文和视频演示。

I was so excited, I wanted to review that information here. Often, I think research is confined to those who do research and inaccessible to those who don’t. None of this work is mine. My hope is that maybe I could present the most interesting pieces of the work and a few graphs to look at the data in a different way to help others understand. One can always look at the video or read the paper, but maybe you just want the graphs.

我非常激动，我想在这里查看这些信息。通常，我认为研究仅限于从事研究的人，而没有从事研究的人则无法访问。这些工作都不是我的。我的希望是，也许我可以展示最有趣的作品和一些图表，以不同的方式查看数据，以帮助他人理解。人们总是可以观看视频或阅读论文，但是也许您只想要图表。

For each plot in the presentation, I wrote a script to pull the data out of the original plots so I could re-plot it. I have added an additional plot showing the degassing as a percentage of the total, which I have found to be a helpful normalization. All of these graphs contain the original data, but some times, I have changed the x-axis tick marks to something I think makes more sense or mixed some data that wasn’t mixed before.

对于演示文稿中的每个绘图，我编写了一个脚本来将数据从原始绘图中提取出来，以便重新绘图。我添加了一个额外的图，显示了脱气占总量的百分比，我发现这对标准化很有帮助。所有这些图都包含原始数据，但是有时候，我将x轴刻度线更改为我认为更有意义的东西，或者混合了一些以前没有混合的数据。

不同的豆 (Different Beans)

Different beans degas at different rates. For espresso, this is particularly important because the amount of gas still left in the bean is related to how a shot will flow. I suspect this means that different beans should be used in different time windows rather than a generic window like 2 to 4 weeks in the case of espresso.

不同的豆以不同的速率脱气。对于浓缩咖啡，这尤其重要，因为仍然留在豆子中的气体量与炮弹的流动方式有关。我怀疑这意味着应该在不同的时间范围内使用不同的豆子，而不是在意式浓缩咖啡中使用2至4周的通用时间窗口。

烘烤水平 (Roast Level)

The darker the roast, the more gas is created! What’s fun for this data is that as a percentage, most of the roast levels have a similar rate and pattern. As the authors of the study pointed out, most degassing (70%) occurs in the first 24 hours.

烘烤越深，产生的气体越多！此数据的有趣之处在于，按百分比计，大多数烘烤水平具有相似的速率和模式。正如研究的作者指出的那样，大多数脱气(70％)发生在最初的24小时内。

烘烤水平与烘烤速度 (Roast Level vs Speed of the Roast)

They looked at dark, medium, and light roasts at three speeds. As percentages, they follow a similar trend no matter the speed.

他们以三种速度看着深色，中度和浅色的烤肉。以百分比表示，无论速度如何，它们都遵循类似的趋势。

I mixed some of these for Fast and Slow to give an idea across the three roast levels.

我将“快”和“慢”中的一些混合在一起，以给出三个烘烤级别的想法。

Again, in terms of percentages, they have a similar pattern for degassing no matter the roast level or speed.

同样，就百分比而言，无论烘烤水平或速度如何，它们都有类似的脱气模式。

烘烤速度 (Roast Speed)

The study also looked at roast speed, and a faster roast had more gas to come out of the beans.

该研究还着眼于烘烤速度，更快的烘烤会使更多的气体从豆类中排出。

整豆vs烧烤(R＆G) (Whole Bean vs Roast and Grind (R&G))

Immediate grinding after roasting drastically changes the gas coming out due to the gas loss during grinding.

焙烧后立即研磨会由于研磨过程中的气体损失而大大改变排出的气体。

磨日期VS烤 (Grind Date vs Roast)

They looked at two roasts over time, and sampled the roasts to grind them at regular intervals. The most interesting thing they found was that at 4 weeks, the amount of gas coming out of the coffee after grinding is more than what will come out of the whole bean. They theorize that this is due to some gases being trapped in the coffee, which would explain why coffee that is months old can still have some crema during espresso brewing.

他们随着时间的推移查看了两个烤肉，并采样了这些烤肉，并定期进行研磨。他们发现的最有趣的事情是，在第4周时，研磨后从咖啡中逸出的气体量要多于从整个咖啡豆中逸出的气体量。他们的理论认为，这是由于咖啡中截留了一些气体，这可以解释为什么几个月大的咖啡在意式浓缩咖啡冲泡过程中仍然会有些生皮。

As expected, the light roast has less gas in the beans and the grinds at the various stages.

不出所料，在各个阶段，轻度烘烤的豆类和磨粉中的气体较少。

We can line up the different weeks past roast for the grounds, and it’s a fun to see how quickly the grounds degas.

我们可以排成一排烤过去几周的时间，这很有趣，看看排渣的脱气速度有多快。

冷冻豆！ (Freezing Beans!)

Their study was very informative to understand what happens when you freeze coffee. The author in the presentation pointed out that they don’t think of the process as freezing coffee beans because most roasted beans have very little water in them. So they consider the beans are cooled instead which slows down degassing. As a result, freezing is an effective method to elongate shelf life. You can also freeze and re-freeze beans which you can’t typically for other food.

他们的研究非常有益于了解冷冻咖啡时会发生什么。演示文稿中的作者指出，他们不认为该过程是冷冻咖啡豆，因为大多数烘焙过的咖啡豆中水分很少。因此，他们认为是将豆冷却，而是减慢脱气速度。结果，冷冻是延长保质期的有效方法。您还可以冷冻和重新冷冻通常不能用于其他食物的豆类。

They looked at beans that were roasted and split between fresh, frozen for 1 week, and frozen for 2. They were ground at the designated time, and the amount of degassing for all three follow a same pattern with a slight dip for 2 weeks vs fresh.

他们查看了经过烘烤的豆，将它们分成新鲜的，冷冻的1周和冷冻的2个。在指定的时间将它们磨碎，这三个豆的脱气量遵循相同的模式，略微浸入2周，而新鲜。

They looked at 70 days in the freezer, and they found the frozen beans degas almost exactly the same as the fresh beans with an offset.

他们在冰箱里看了70天，发现冷冻豆的脱气几乎与新鲜豆一样，但有偏移。

额外红利：咖啡香气 (Extra Bonus: Coffee Aromas)

Samo also did some work on different aromas that come out of the beans in order to look at coffee freshness. The specific chemicals have attributed tastes below. Each one contributes to different components of taste as aromas are complex.

萨摩还对咖啡豆发出的各种香气进行了一些研究，以了解咖啡的新鲜度。特定化学物质归因于以下口味。由于香气复杂，因此每个成分都有助于味道的不同成分。

The original plot shows a drop, and I adjusted the X-axis to be one week intervals. My aim is to get a graph and some tables that help clearly show how much aroma is left by week. So I also renormalized the data for their maximum and minimum.

原始图显示下降，我将X轴调整为一周间隔。我的目的是要得到一张图表和一些表格，以帮助清楚地显示每周剩余的香气。因此，我还针对其最大值和最小值对数据进行了规范化。

What this chart is missing is CO2. So I took one of the degassing curves from the section above titled “Roast Level vs Speed of the Roast.” I used the medium roast at the medium speed.

该图表缺少的是二氧化碳。因此，我从上面标题为“烘烤水平与烘烤速度”的部分中选取了一条脱气曲线。我用中等速度烤。

CO2 degasses very quickly relative to aroma, which probably explains why the best time to brew espresso is 7 to 21 days post-roast. I have been hitting the range of 21 to 35 days because I can get a higher extraction level (~22% Extraction Yield).

相对于香气，二氧化碳会非常快速地脱气，这也许可以解释为什么煮浓咖啡的最佳时间是烘烤后7到21天。我可以达到21到35天的范围，因为我可以获得更高的提取水平(〜22％提取率)。

Here are some tables to bring a more concise summary. In the first, you can see that CO2 depletes the quickest while Methanethiol is the slowest. If you look at the second table, that is done with respect to each week. After 2 weeks, 3 of the 4 aroma parameters are still near 50% of the starting point while CO2 is very low. After 6 weeks, most of these aromas are at their lowest point. It doesn’t mean they are gone because these were normalized values with respect to their maximum.

这里有一些表格可以使摘要更简洁。首先，您可以看到二氧化碳消耗最快，而甲烷硫醇消耗最慢。如果您查看第二张表，则相对于每周而言。 2周后，4种香气参数中的3种仍接近起点的50％，而CO2非常低。 6周后，这些香气大多数处于最低点。这并不意味着它们消失了，因为这些是关于最大值的归一化值。

Overall, I was very surprised to run across this research, and I was very excited to play around with the data. It doesn’t change how I’m looking at espresso, but it does help provide extra explanation to the amount of off-gassing I’ve measured using a scale that’s accurate to 0.03g.

总体而言，我对这项研究感到非常惊讶，并且对数据的处理感到非常兴奋。它不会改变我看待特浓咖啡的方式，但确实有助于提供额外的解释，以证明我使用精确至0.03g的秤测得的除气量。

I’m hopeful further research will help improve the way I roast and store coffee beans. Of course, the trouble in the field is the wide variety of coffee beans, roasters, and brew methods.

我希望进一步的研究将有助于改善烘焙和储存咖啡豆的方式。当然，该领域的麻烦是各种各样的咖啡豆，烘焙器和酿造方法。

If you like, follow me on Twitter and YouTube where I post videos of espresso shots on different machines and espresso related stuff. You can also find me on LinkedIn.

如果您愿意，请在Twitter和YouTube上关注我，在这里我会在不同的机器上发布浓缩咖啡的视频以及与浓缩咖啡相关的内容。您也可以在LinkedIn上找到我。