Q: My recipe calls for malt flour - which product is this?
A: The term malt flour is quite vague and will need some understanding of the reason for the ingredient in the recipe. We have spraymalt which is a dried malt extract in the form of a flour. We also have Diax which is a diastatically active barley flour for naturally improving dough rise and bake. Non-diastatic flour such as Roasted Barley Malt (RBM), Nut-brown or red-malt are used to give a natural colouring and a little malty flavour to bakes such as bagel or malt-loaf for example.
The clue may be in the recipe preamble. If you are making a malty drink then it is likely that it is one of the spraymalts that you need. These come in light, dark and extra-dark and give a malty-sweet flavour and some colour (delicious in a milk shake).
If it is for a cake and the recipe already has other sugar in it then it may be that one of the non-diastatic flours (Roasted Barley Malt (RBM), Nut-brown or red-malt) is needed to give the bake some colouring. If there is no other sugar in the recipe then it may be a spraymalt for malty-sweetness.
If the recipe is for bread and the quantity of malt flour is about 1% of the flour (about 10g for every 1000g flour) then it is likely that Diax is needed and is being used to make the dough more responsive and bake better. The alternative is that it may be a colouring that the recipe intends and this would be one of the Roasted Barley Malt (RBM), Nut-brown or red-malt.