It's not hard to make your own almond flour, and if you make almond milk you're already half way there because you can use the leftover pulp.
If you are going to grind it from whole almonds rather than using almond pulp I would still recommend first soaking the almonds from 5-12 hours and then discarding the soak water, rinsing and dehydrating them until crisp. You can then grind the dry almonds into flour, and they will be much more easily digestible.
How to make almond flour from almond milk pulp
If you use the pulp left over from making almond milk, just spread the pulp out evenly over a dehydrator tray covered with a non-stick Teflex sheet. Depending on how much almond pulp you have you may need to spread it over two or more trays.
Turn the heat to 105 degrees or lower if you want to keep the almond pulp raw for use in raw vegan dishes. Otherwise you can turn the heat up to 110-115 and dry it faster if the almond flour is going to be cooked anyway.
After the almond pulp is dried, put it back into a food processor or coffee grinder to break up any clumps there may be and grind the flour to a finer texture. It's now ready to be used in your recipes.
You can store the almond flour, almost indefinitely. Just keep it out of direct sunlight and heat.
How to make almond flour from whole almonds
Soak the almonds for overnight (or for at least 4 hours), in double the amount of water needed to cover them.
Drain, rinse if needed, and throw away the water.
Dehydrate at 105 degrees F or less for 24 hours or until the almonds are crunchy again.
Store the almonds in a cool place, out of direct sunlight. Grind into flour as needed in a food processor or coffee grinder.
Why soak almonds?
It's important to soak nuts (and beans/legumes and grains as well) to neutralize the phytic acid and enzyme inhibitors that they contain, making them more digestible. If it's not neutralized the phytic acid can bind important minerals like zinc, magnesium and calcium, making it harder for your body to absorb them.