Combine water, vinegar, salt, and sugar in a small stockpot.
Bring to a boil, stirring to incorporate the sugar and salt.
While mixture is heating, break the woody ends off the asparagus.
Place asparagus in a loaf pan or other small pan.
Cut jalapeno into rings, and place in pan.*
Once vinegar mixture boils, pour over asparagus.
Cover with foil, and let sit on counter for 30 minutes.
Transfer to refrigerate, and allow to chill for at least 24 hours.