http://seattletimes.nwsource.com/html/foodwine/2008169335_lemonprices10.htmlI was suspicious before the article was published. The lemons in the store aren't very good.
Uwajimaya (local Japanese grocer/department store) has Yuzu trees for sale. Yuzu is Citrus juno, a weirdly cold-hardy Citrus that will survive in places like Seattle and London. But I don't know if anyone has actually ever gotten fruit. I know people who have kept the trees alive, but I have yet to hear of someone announcing his harvest.
Yuzu juice makes a good "sour" for cooking.
Another good option would be an "Ichang Lemon", which is a hybrid between an Ichang and a Pommelo. The fruit is lemon-like and aromatic--good enough, they say, to make mock-key-lime-pie.
And speaking of limes, I want an "Australian Desert Lime"--Citrus glauca--not really a lime, but a lime-like Citrus from the interior of Queensland and South Australia, that produces small lime-like fruits. It is cold-hardy in terms of brief dips down to about 10F (it has to put up with radiation frosts in habitat--but I doubt it will tolerate long freezes), and it is unique among the citrus for being xeric (that is, it grows in dry places). It should have no trouble surviving the 6 month dry-season and occasional mild frosts where I will be looking for farmland. What I need is a source of fresh seed to import. Citrus are easy to grow from seed. Oddly, they sometimes breed true, because they sometimes produce "parthenocarpic" seed (seed produced without pollination).
Most common citrus, by the way, are complex hybrids. Ichangs (Citrus ichangensis), Trifoliate Oranges (Poncirus trifoliata), and Australian Desert Limes are among the exceptions, all being species. I think Kumquats are pure too--Fortunella. When you cross one of these with a more typical Citrus, their flavor tends to dominate. That is a big problem with Trifoliate Oranges, which can be crossed with Sweet Oranges to produce "Citranges", which are much more cold-hardy than Sweet Oranges but have the dryish fruit and bitter overtones of the Trifoliate Orange. You can juice them to make bitter orange-aide.
Those, crossed with Kumquats, produce "Citrangequates", like "Thomasville". Well, now you have a tree that's really hardy (Kumquats tolerate quite a bit of cold if they are slowly brought to dormancy, and Trifoliate Oranges are extremely coldhardy), but now the fruit is rather small AND seedy AND sour. Fully ripe they are considered marginally palatable but you're better off either juicing them or making marmalade out of them. But I think they would work well for marinades and dressings like lemon juice.
Many years ago it was realized that Citrus crosses with Poncirus, and people were predicting orange trees that would grow in Boston. But it never quite happened. It's hard to separate the bitterness from the coldhardiness. Ichangs are perhaps more promising, being aromatic, but having almost no pulp! (that is, the fruit is nearly all rind).
I'll post more about these tantalizing hybrids on another board.
