Crystal malts are made by wetting and toasting pale malts. The process caramelises the sugars inside the grain, so they're often also called caramel malt.
Crystal 30L has only been lightly roasted and has subtle flavours and smells.
Because the starch in crystal malts in already largely converted to sugar they can be steeped directly in warm water, without the need to mash,
For this reason they're popular with extract brewers who want to add depth of flavour and body to their beers.
Not a lot of noticeable aroma but smells slightly sweet and bready.
After steeping, Crystal 30 malt tastes fairly watery. It's not especially sweet, although there is some sugary flavour.
It tastes of the malt itself, more than caramel.
In terms of colour it looks very similar to a cup of tea.
Bitters and other English ales