being japanese..i love going to the bookstore for dessert books. i noticed though, a lot of the use "almond powder" and i know they sell them in japan but can i find them here? in los angeles? or is it just almonds crushed in to powder?
Nuts deteriorate quickly when no longer whole. Nothing ruins a dessert faster than rancid nut oils. You can easily make your own fresh almond meal or 'flour' by grinding whole nuts with a bit of the sugar called for in your recipe. The sugar keeps them from turning to butter, as the high fat content will do in a powerful processor, if you don't closely monitor it.
Use short pulses, and pick out any large pieces that refuse to break down. Don't continue to pulse or the flour quickly comes together in a paste, and is unusable in your recipe.
I add 1/2 cup hazelnut meal to almost any cake I make, and it can turn a boxed cake mix to something actually edible.
Good luck, and try making your own before you purchase pre-ground nut meals. You'll notice an incredible difference.
You should look at the cook books carefully to see what they mean by 'powder'. What other posters have been describing is usually called 'almond meal', that is, ground nuts. I'd expect to find this in certain European baking recipes. Marzipan (almond paste) may require a finer grind.
However if the recipe is Asian, it may be calling for something different. I have, for example, a container of 'Almond Powder' from Hong Kong. Its ingredients are sugar, almonds, milk powder, etc, and is sold primarily as a drink mix.
On the question of whether you should grind your own nuts, or buy preground, there are trade offs. The availablity of nut meal from a shop like Trader Joes means that I am much more likely to include it in a recipe (such as a sweet potato bread that I am now baking). Only if I am making a special chocolate walnut (flourless) torte am I likely to grind my own. We are constantly balancing convenience and freshness, whether it involves nuts, spices, coffee, or soup bases.
I've found making my own almond powder to be a big PIA. And, I agree that the TJ's product might be too coarse. I know I've bought it before and didn't like it too much.
I buy my almond flour from Mandelin, which grows almonds here in California. It's fresh and stays that way in the refrigerator for quite a while.
I like Mandelin too, a consistently good product.
Another difference in purchased powdered/ground almonds is almond flour vs almond meal. According to pastry chef Sherry Yard, almond flour is a fine powder ground from almonds after they've been pressed for their oil. Almond meal is ground from whole almonds and slightly oilier and grittier.
Also the skin-on vs blanched issue affects final color, texture, and flavor of a dessert.
I just made marzipan and had difficulty processing an extremely fine grind of almonds in my machine, but for something like the clementine cake, no problem with a coarser grind of blanched almonds. As toodie jane said, a bit of sugar does help keep it powdery.
I'm not sure if almond flour is the same as the almond powder you're looking for. But if it is, you can get some from The Baker's Catalogue. The site is www.bakerscatalogue.com. They have almond flour and toasted almond flour. I would think they go through a lot of it, especially at this time of year, so that may bode in favor of it being fresh.