How did missionaries in the past (when there were no mail or shipment services) maintain a supply of wheat hosts and wine to celebrate Mass in the mission field?
Even if the priest took some with him, they would eventually run out, and wheat and/or grapes are not accessible everywhere. Also, hosts would eventually go stale and be at least doubtful matter for the Eucharist.
I know that native substitutes for wheaten bread and grape wine could exist, but they would be invalid matter (e.g., rice flour or some sort of liquor).
Even if the priest took some with him, they would eventually run out, and wheat and/or grapes are not accessible everywhere. Also, hosts would eventually go stale and be at least doubtful matter for the Eucharist.
I know that native substitutes for wheaten bread and grape wine could exist, but they would be invalid matter (e.g., rice flour or some sort of liquor).