Me yasa kwalaben giya kore?

Tarihin giya yana da tsayi sosai. Giyar farko ta bayyana a kusan 3000 BC. Semites a Farisa ne suka yi shi. A wancan lokacin giyar ma ba ta da kumfa, balle a yi kwalliya. Har ila yau, tare da ci gaba da ci gaban tarihi cewa a tsakiyar karni na 19, an fara sayar da giya a cikin kwalabe na gilashi.
Tun daga farko, mutane suna tunanin cewa gilashin kore ne - duk gilashi. Misali, kwalabe na tawada, kwalabe na manna, har ma da tagogin taga duk kore ne, kuma, ba shakka, kwalaben giya.
Saboda tsarin kera gilashin na farko bai girma ba, yana da wuya a cire datti kamar ion ferrous a cikin albarkatun ƙasa, don haka yawancin gilashin a lokacin kore ne.
Tabbas, lokutan suna ci gaba da haɓakawa, kuma tsarin samar da gilashin ya kuma inganta. Lokacin da ƙazantar da ke cikin gilashin za a iya cire gaba ɗaya, kwalban giya har yanzu kore ne. Me yasa? Wannan shi ne saboda tsarin cire ƙazanta gaba ɗaya yana da tsada sosai, kuma irin wannan kayan da ake samarwa kamar kwalaben giya a fili ba shi da darajan tsadar gaske. Kuma mafi mahimmanci, an gano kwalabe masu launin kore don jinkirta tsayawar giya.
Wannan yana da kyau, don haka a ƙarshen karni na 19, kodayake yana yiwuwa a yi gilashin haske ba tare da datti ba, har yanzu mutane sun ƙware a cikin kwalabe na gilashin kore don giya.
Duk da haka, hanyar da za a shawo kan koren kwalabe ba ze zama mai santsi ba. Beer ya fi "tsoron" haske. Hasken rana na dogon lokaci zai haifar da karuwa kwatsam a cikin tasirin tasirin abubuwan daci a cikin giya, oxalone, don haka yana hanzarta samuwar riboflavin. Menene Riboflavin? Yana amsawa da wani abu mai suna "isoalpha acid" don samar da fili mara lahani amma mai ɗaci.
Wato giya yana da sauƙin wari da ɗanɗano lokacin da hasken rana ya fallasa.
Saboda wannan, a cikin 1930s, kwalban kore yana da kishiya - kwalban launin ruwan kasa. Lokaci-lokaci, wani ya gano cewa yin amfani da kwalabe masu launin ruwan inabi don shirya ruwan inabi ba zai iya jinkirta dandano na giya ba fiye da kwalabe na kore, amma kuma ya toshe hasken rana yadda ya kamata, ta yadda giyan da ke cikin kwalban ya fi inganci da dandano. Don haka daga baya, kwalabe masu launin ruwan kasa a hankali sun karu.