Question about sour oranges.....

I hope this is not a dumb question......I moved into a house that has in the back yard a full grown grapefruit tree right next to a full grown orange tree (valencia, I think?). There is also a smaller citrus tree nearby. The owner of the house, who had been renting it out for some time, wasn't sure what the smaller tree was but thought it was limes. It's not......they took a very long time to ripen but they are about the size of tangerines. They may even be tangerines and peeled like tangerines.....but....

I peeled and tried the small fruit and also the larger oranges...they are both very sour. I expected this from the grapefruit - and boy are they sour - but am surprised how bitter and sour the oranges here.

So my question is (finally)......is there any reason they are so sour? Is there anything I can do about it?

Thanks for your help,

Lee

There are a couple of possibilities. The first possibility is that there are some types of oranges that are bitter/sour, so it could be that's what you have, in which case there's nothing you can do to change the flavor besides buy a new tree. The second possibility is that they weren't ripe yet. I haven't done too much with citrus so I don't know how to tell if they're ripe or not, but I suspect they would taste sour if picked before they were ripe (I'm pretty sure you can't just go by looks on the ripeness--I think they are orange colored for a while before they're actually ripe). The third possibility is that most oranges need a certain amount of summer heat to sweeten them, and some parts of CA don't get hot enough for them to sweeten up well. I suspect that Pasadena probably has hot enough summers for the oranges (it's mostly up here along the coast where that's a problem), but I figured I'd mention it just in case you have cooler summers than I'm guessing.

Hi,
I have a similar situation here, in Miami.
The house I moved in over a year and a half ago has many fruiting trees, actually all of the trees are fruiting trees. However, the orange trees (let's call them this way) have bitter-sour fruits. I caught two harvesting seasons and there was no difference in the taste. I waited and waited for them to "ripe" until all of them were gone... The postman (a very nice cuban-born living in Miami for ages) told me they call them "naranja agria", and they use it to sour-flavor food. Mine are the size of tangerines, very juicy, but they do not peel easy, though... I root for Ecrane's first possibility. If it's your own house, maybe wait one more season, and if there is no improvement in tast, just buy good ones.

The other possibility on the smaller tree is that it may have originally been a nice tasting orange--many dwarf citrus trees are grafted onto 'Flying Dragon' rootstock, which is a cultiavar of Poncirus trifoliata. It produces bitter tasting fruits (one of its common names is bitter orange). Sometime when the original tree was young, maybe it was damaged by a cold snap and the top died back, then the tree grew back from the rootstock, but instead of being whatever nice fruits you were supposed to have, you'd get the bitter orange fruits instead. I guess that's really the same as the first possibility, but it's a way you could have ended up with bitter oranges by accident instead of someone purposely planting a sour/bitter variety of orange.

Thank you guys for the responses.

I am thinking with the larger tree it could be combination of lack of heat and perhaps not fully ripe (though the one I picked seemed 'older' and I thought it was ripe, but it is hard to tell). Though our summers are plenty hot, the moderate climate here means the trees (with the exception of the fig tree) bear fruit all year round and it has been rainy and cool here during the winter months so perhaps this last batch didn't get the necessary sun and heat for sweetness. I thought I remembered last summer trying a couple of oranges off of that tree that were not so sour so I had wondered about the amount of sun/heat as well.

We'll see what happens later in the year perhaps....especially with the little one. It took MONTHS for the green fruit on it to turn orange and so I thought they were ripe. But perhaps they are not quite done cookin'. Or perhaps they are just born to be sour little suckers!