Scrape the surface off of the carrots and wash in cold water. Small carrots can be frozen whole but large carrots should be sliced.
Place them into boiling water and boil at a high heat for 2 minutes (known as blanching) for sliced carrots or 5 minutes for baby whole carrots.
Drain off the boiling water ad run them under cold water for a minute.
Drain them well and dry with absorbent kitchen paper.
Pack the blanched carrots in a freezer bag separating usable portions with cling film.
Place the labelled and dated bag in the freezer. They will keep for 3 months in a standard freezer.