عملية التخمير بالغمر

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التخمير بالغمر الثابت

IM 3.03 اختبار المتغيرات في التخمير باستخدام المكبس الفرنسي - الجزء الثاني

مقارنة بين وضع الغطاء وعدمه

هل هناك حاجة إلى تغطية المكبس الفرنسي؟ وهل يحدث ذلك فرقًا؟ لمقارنة آثار استخدام الغطاء، قمنا بإعداد مجموعتين من المشروبات، إحداهما بغطاء والأخرى بدون غطاء. يوضح هذا الجدول إجمالي نسبة المواد الصلبة الذائبة لكل الاختبارات التي أجريناها، سواء بغطاء أوبدون غطاء.

From these tests we found that extraction yields were higher on average with the no lid approach but a little more consistent with the lid. Some of this difference is attributable to evaporation, i.e. the brews with the lids removed would have allowed more water vapor to escape and so become more concentrated for that reason. Nonetheless, this difference in extraction is considerably larger than the expected water loss due to evaporation. We can only speculate that some interaction between the water vapour and the crust at the top of the coffee may cause a change in how extractable the coffee becomes when a lid is used. For this reason, we recommend you only use a lid after إزالة الطبقة القشرية of your coffee when you brew a French press. 

 

Plunging-Only vs. Breaking the Crust

Some cafés prefer to set up French presses and deliver them to customers, sometimes accompanied by a timer, immediately after adding the water. The customers do the plunging after a specified amount of time. This process can be particularly effective in large catering environments where many people must be served coffee simultaneously. One problem with this approach is that carrying a French press to a customer has the effect of ‘إزالة الطبقة القشرية’, which affects the brewing process. It’s best to avoid any movement of your French press in the period between adding the water and إزالة الطبقة القشرية.  

There are benefits to manually agitating the grinds and إزالة الطبقة القشرية, rather than simply pushing down the plunger. Stirring the mixture may help to incorporate solubles that may have dissolved in the coffee bed but haven’t had time to diffuse into the part of the brew that will eventually be consumed.