My Meyer lemons usually ripen up in December, but they also tend to get a bit of an orange hue to them. I'd go ahead and pick one and try it.

Thanks! Mine are bright yellow, no orange at all. I don't know much about Meyer lemons, I bought the tree on a whim because it was only $5 at sprouts. It was so tiny, though (and still is) I've never even eaten a Meyer lemon before, so I'm not sure I'd know if it was ripe or not! :) Do you have problems with chlorosis with your tree? Mine greens up pretty well in the winter but is very chlorotic the rest of the year in spite of fertilizing.

They don't always turn orange. I've bought Meyer lemons from the store that were yellow but perfectly ripe. I'd go ahead and try one. They should taste like a lemon but be less acidic.

If you have chlorosis it's either an issue with pH or a micro nutrient issue. See if you can get citrus growers blend from a local nursery and follow the instructions.