|Testing different torage solutions|
The testing is about its end and has revealed some quite interesting results. It has been exactly four weeks since I have sealed the three chosen storage solutions, seeking the optimal solutions of keeping the freshness of the roasted beans. The three chosen storage solutions was a CO2 valve bag, a basic paper bag and a normal plastic bag, if you want to read more about the set up of this experiment, see link.
There has been a 14 days milestone in this experiment, where there was similar testing as the above picture shows. The result of this milestone revealed a identical crema layer of the three different solutions, but a different development in the flavors and notes. If you are interested in the conclusion of this milestone, see link.
The surface of the roasted coffee beans were generally the same, as the 14 days milestone also revealed, but the paper bag had a slightly less greasy surface, I suspect the fat sucking paper within the paper bag. The plastic bags maybe had the most greasy bean by a closer look, but almost identical with the CO2 valve bag. The conclusion of the 14 days milestone was a minimal differentiate between the storage solution in surface appearance, but after four weeks there was quite a difference and I would honestly say that it would make an impact on the flavors.
The crema layer was after 14 days equal to each other, likewise the color and visual brewing on the naked portafilter. The crema layer comparison revealed a thinner crema layer of the plastic bag storage solution, but besides that an identical layer and appearance. After four weeks of storage the result has taken a turn, cause the crema layer has adjusted to the different storage solutions. With that I mean, the plastic bag solution had a thin crema layer and quickly turned blonde, while the paper bag had a more consistent and brown reddish crema layer. The most expensive storage solution had the best extracted crema layer, which was the most smooth, consistent, brown reddish and had by far the best smell, so in turns of appearance the CO2 valve bag would have won.
I´m a fan of taste instead of appearance and hereby comes the most important points; the plastic bag shot had only bitterness to offer with a long and unpleasant aftertaste, it actually balanced with being undrinkable. The paper bag shot revealed a more balanced taste, with the bitter, sour and sweetness flavors which was almost lovely, but had a quick aftertaste. The CO2 valve bag had the most flavors and notes, with flavors of caramel and a good balance likewise the paper bag. The CO2 valve bag offered the most pleasant aftertaste, which made this shot the best of the group.
The conclusion of this experiment at the finish line, will draw a picture of the unimportance of chosen a storage solution in the short run, but when keeping roasted beans at a longer time, the choice of storage solution will have a great impact on the extraction and flavors.