Because cucumbers are watery, the sandwiches are best assembled just a few hours before serving to keep them from becoming soggy.
How to Keep Sandwiches from Getting Soggy in a Lunchbox
FAQ
How do you keep cucumbers from getting soggy in a sandwich?
20 minutes is all it takes to avoid soggy cucumber sandwiches. To avoid soggy cucumber sandwiches with little added prep time or effort, all you need to do is give them a quick salt. The reason this simple method works is due to osmosis, which draws out the veggie’s excess water.
Can cucumber sandwiches be made in advance?
Cucumber sandwiches are best made just 1 to 3 hours ahead of time, but they can be made up to a day in advance. But if you decide to make them ahead, you run the risk of them turning mushy.
How do you keep cucumber sandwiches fresh overnight?
If you need to make cucumber sandwiches ahead of time, keep them in a sealed container for a few hours, and refrigerate them. You can put a paper towel on top of them which will absorb moisture.
How do you keep cucumbers crispy?
Therefore, cucumbers will last longer if you store them, dried and wrapped, in a mesh produce bag or something that allows for a bit of airflow. Some air circulation will keep the cucumbers crisp, dry, and fresh for a longer period of time.