Peas are fairly easy to grow, but tricky to harvest. They ripen fast, with a narrow window to get them just right in order to hit the maximum sweetness and texture. We grow vining peas, which produce a continous crop as long as conditions allow, as oppoesd to bush peas, which ripen all at once, and only once. Below, you see a comparison of developing peas:
The top pea is not ready yet; still too small and too thin. It won't be very sweet. The middle pea is perfect; starting to round out, but not yet cylindrical. It will be juicy and tasty. The bottom pea has gone too far; it's bloated and round. It will have lost some sweetness and be a bit tough. I try to check every day to make sure I'm getting each pea just at its peak.
Like some other produce (greens especially), peas are sensitive to heat after being picked. They really ought to be chilled instantly once they're off the plant; sitting in a bucket in the sun for even a few minutes and they may start to lose some of their peak sweetness and quality. We've started harvesting directly into buckets of cold water, so as to flash-chill the peas and keep them perfect.
This is a lesson learned, ironically, from industrial agriculture. At the Great Plains Vegetable Conference in January, I heard a fascinating talk about the methods large farms use to increase quality, such as driving refrigerated semis directly into the fields so produce could be instantly chilled. The point driven home in this talk was that if these folks go to such lengths to preserve what quality they do have, small farmers growing really high-quality produce ought to take the same care. With our new water line and hydrants in the garden, we can now harvest greens, peas, and any other relevant produce directly into cold water, improving both their quality and their shelf life.