I grew cucumbers the last two winters in my hydroponic setup and noticed that the flavor more resembled water than cucumber. I suspect the temperature in my growing area is not warm enough. It’s around 75˚F. Any suggestions?
Unlike tomato fruit, cucumbers don’t tend to develop a particularly strong flavor: however, they shouldn’t taste like water. There can be a number of causes for a lack of that distinctive cucumber-ness, and they are largely related to genetics and/or growing conditions and nutrition. Firstly, flavor strength—which is made up of sugars, acids, volatiles, and other compounds—varies somewhat between the different types of cucumbers. Older, open pollinated varieties and types tend to have a stronger flavor, but are prone to bitterness. Greenhouse, hydroponic hybrids, on the other hand, are milder in flavor, unlikely to become bitter, and higher yielding.
Growing environment also plays a role the development of flavor compounds. A temperature around 75˚F is fine (optimal temperatures are 72-82˚F) unless the nights are much colder than this.
Nutrients play a significant part in cucumber quality, too, as the plant has a very high requirement for potassium (K) in the fruiting stages. It’s recommended to use a K booster or high-K fruiting formulation during fruit development, along with some additional calcium. Also, run a higher EC in winter (around two to 2.2). Some growers have found the addition of silicon to the nutrient solution assists flavor and fruit quality in cucumbers, too. However, silicon supplements can push the pH of the nutrient solution up, so that requires extra monitoring and adjustment.
Avoiding overwatering and saturation of the growing medium also assists with improving compositional fruit quality and flavor strength. Light may be another issue; cucumbers need a lot of light, and if sufficient light is not present for maximum photosynthesis, the fruit won’t get enough sugars. This can result in poor flavor. Similarly, if the plants are carrying a high fruit load, then the supply of sugars (assimilate) allotted to each individual fruit is restricted. In this case, pruning fruitlets to reduce numbers may be beneficial.
Finally, the stage at which the cucumber fruit are harvested and how they might be stored also plays a role with flavor. Cucumbers that are harvested fairly immature tend to have a milder, less developed flavor, while those that are over mature develop a watery, sometimes bitter flavor. Once harvested, cucumbers should be eaten as soon as possible. They do store well under refrigeration wrapped in plastic, but if storage is more than a couple of days, this does reduce compositional quality. The cool conditions in the refrigerator are likely to effect volatiles that contribute significantly to that cucumber flavor.
Hope that helps, and good luck with the next crop.