meyer lemon tree has bitter fruit

Question

What could cause my twenty-year old Meyer lemon tree to produce bitter fruit? The lemons used to be sweet and tangy but now are unpleasant tasting. Due to drought conditions in California, I have cut back on water, but the tree looks healthy and continues to produce lots of normal-looking lemons. I fertilize it with standard citrus granules three times a year.
Thank you.

Answer 1

I would increase the watering. Soil should be damp, not soggy, drying slightly between watering.

https://www.gardeningknowhow.com/edible/fruits/lemons/growing-meyer-lemons.htm
https://www.gardeningknowhow.com/edible/fruits/lemons/learn-about-fertilizer-for-a-lemon-tree.htm