The base of a groundbait mix

The base is the largest part of the mix by volume, which is exactly why its role gets misunderstood most often. The base is a carrier, not food: the bulk that everything else is distributed through, and the material that sets the weight and how fast it soaks up water.

What it's made from

Ground breadcrumb is the usual base: neutral, light, quick to soak up water. Biscuit meal is sweeter and richer, and holds moisture differently. Ground cereals and bran are cheaper, with a different particle structure. The difference between them is in the grind and in how much water each takes up.

Grind matters more than the raw material

The same breadcrumb, ground fine, produces cloud and a light particle that hangs in the water column for a long time. Ground coarse, it falls faster and stays on the bottom. That's why mixes for different depths are made from the same product ground differently.

How much water the base takes up

This is the property that makes one mix easy to moisten while another has to be worked at for a long time. A rich, oily base takes up water slowly and reluctantly; a dry, porous one takes it up fast and in quantity. That's why water is added in stages: the amount right for one base over-wets another.

Light base and dark base

The base's colour shows on the bottom, and it's not cosmetic: a light patch on dark silt is visible from far off, including to fish that weren't called there. That's why, where the bottom is dark and the fish are wary, the base is either chosen darker or darkened with soil.

How much the base weighs

On its own it's light, and a mix made of nothing but base scatters through the water column, barely reaching the bottom as a solid patch. That's sometimes what's wanted, but more often the base has to be weighted down with soil — otherwise the whole mix ends up working somewhere other than where it was cast.

How much it feeds

The base has food value, and it's the part that most easily overfeeds fish without anyone noticing: it's fine, there's a lot of it, and fish pick it up off the bottom with no effort. That's exactly why the base is diluted, not concentrated.

How the base behaves in cold water

In winter fish eat less, and the same volume of base becomes an excess. That's why the winter mix is made poorer: without changing the raw material, what can be eaten out of it is reduced, and the share of what can't be filled up on is increased.