She said the dimensions have not been finalised yet, but are likely to be about 800mm square.
The whole community is invited to the birthday celebrations that will include a festival-style party with bouncy castle, food stalls, free products, kapa haka displays by college students, mazes, mini golf and spin art.
"The giant allsort will act as our birthday cake. The rules require the product is used, so it has to be eaten. We'll be cutting it on the day, hopefully once the record has been achieved, and everyone is invited to have a piece."
Mrs Law said leftover allsort will be given to The Salvation Army, their chosen charity for the day, to distribute within the community. "The really important thing is that the allsort gets eaten, we don't want to throw any away."
Mrs Law could not confirm how many kilos of ingredients would be used, only that they had to be in the exact same ratios as a standard licorice allsort.
"All of that will be recorded when we make it and we'll release the information afterwards."
RJ's is estimating it will take about three hours to make the giant allsort. Some of the preparation work will start the day before, to allow the licorice to rest, but otherwise it will all be made Friday morning, starting about 6am.
There will be two witnesses at all times to ensure everything is "above board" and all the ingredients recorded, said Mrs Law.
She thought the allsort should be ready by about midday for the 'cake cutting'.
"It's a really good event to get all the team [about 60 staff] involved and the community and have a really good celebration of 21 successful years."
Roger Halliwell bought Levin-based Grannies Licorice in 1983 when the factory was going into receivership. The factory was later sold to Arnotts, then to Nestle. Halliwell and his son Regan James brought the factory back in 1994, when Nestle moved its plant to Auckland, and started selling their iconic licorice confectionery under the renamed RJ's Licorice brand, named after Regan.
RJ's Licorice was sold to the Australian Quinn family in 2015. The only Halliwell family member to still work at the company is Mrs Law, Halliwell's daughter.
"It's nice that RJ's is still carrying on a family tradition," said Mrs Law.
RJ's Licorice is poised for expansion as it looks to increase its exports to Australia but in the meantime, there's a giant allsort to be made.
Celebrations start from 6am.