Bacterial soft rot

[Sheepish]

Some of my cabbages have been showing a little brown slime on them. Initially I put this down to a combination of slug or caterpillar damage and damp conditions, not having much negative effect. I've been concentrating on harvesting the affected ones and by cutting out the bad bits we have got plenty of edible stuff from them. However what's left of the one currently in the veg rack has now got more slimely rotten bits and a quick Google has shown it to be bacterial soft rot.

There are three Golden Acre outside showing light symptoms which I think I now need to remove before they get any worse and risk spreading to the other brassicas around. Two questions:

Other than what we can eat straight away, is it safe to shred, blanch and freeze the good leaves?

Can the diseased remains go on the compost heap? If not will they do any harm in the green waste bin (as I understand it the large scale council composting works in a different way to my garden heap) or are they best chucked in the general rubbish?

Actually better make that three questions. I've never had this before, is there any advice on future prevention?

[OllieMartin]

Not sure about the first couple of questions.

In terms of future prevention:

Warm, wet conditions favor soft rot development. Therefore, select fields with good drainage. It is best to irrigate at night when dew is present.

Avoid high nitrogen rates with susceptible varieties. Increasing nitrogen does not increase the amount of disease with resistant varieties.

Surfactants, which are in most insecticides, also have been shown to increase soft rot severity. Therefore, get insects under control before soft rot begins to develop. If an insecticide must be used when soft rot is present, applications should be made when rain is not forecasted.[3]

Finally, cut heads such that the stem stump is angled to permit water run-off. Water pooling on a flat stump will provide favorable conditions for soft rot. Bacteria in rotting stem stumps can be dispersed to heads not yet harvested.[3]

Bacterial soft rot - WikiGardener