Working From Home

I’m writing this from my “home office,” also known as the attic, in the midst of the pandemic lockdown that has affected so much of the world in the last few months. I hope that by the time you are reading it things have calmed down a bit and are getting back to normal, but I suspect that we will be in this situation for some time to come.

One of the top news stories in the early days of lockdown was about shoppers panic buying and stockpiling what they deemed to be necessities—we now know that civilization is powered by hand sanitizer and toilet paper. The follow up to the initial story told of a large increase in food waste as much of the stockpiled fresh produce went rotten because it couldn’t be used fast enough. This was then followed by a spike in the sales of refrigerators and chest freezers.

This got me thinking about the problems of freezing food at home. It’s generally accepted that fresh food taken home and put in the deep freezer gives better quality than food that is already frozen when you buy it.Generally accepted, but wrong! I have often said over the years when people repeat this fallacy within earshot “Would you rather have your food frozen by professionals or amateurs?” An industrial blast freezer is a custom-designed wind tunnel, specially engineered to ensure maximum velocity across products without damaging them and ensuring that heat is removed as quickly as possibly. Vegetables which are frozen in a fluidized bed will change phase within a few seconds ensuring that the integrity of the cell structure is maintained as best as possible, and the quality of quick-frozen meat is preserved by preventing the migration of salts through the product as the freeze-front progresses. Ice cream is even more tricky as the “consumer experience” is heavily dependent on the temperature-time profile through the life of the product. This was explained in more detail in my August 2017 column.

Putting fresh food into your freezer at home creates lots of problems. The amount of heat to be removed in turning the water content of the food from liquid to solid is huge compared to the heat load required to maintain a low temperature. The typical domestic freezer struggles
to maintain temperature when overloaded this way. This means that not only does the quality of the stuff being frozen suffer because the freezing process takes too long, the quality of the stuff already being stored in the freezer is also at risk. Meat might become rubbery or tasteless (particularly at the surface), fruit could turn to mush, and ice cream is likely to be gritty and unpleasant to eat.

Here are a few tips to minimize these effects. Keep already frozen food separate from stuff that’s being frozen in a separate compartment or, even better, in a second freezer. Break food to be frozen down into individual portion sizes, or even part-portions, so that it will freeze as fast as possible, even if this means thawing several packets for a single meal. Pre-chill cooked food so that it is as cold as possible when it goes into the freezer and pack it with a prefrozen glycol block to minimize the load on the freezer.Wrap all produce to eliminate moisture loss. Best of all: buy your food from the store frozen by professionals and get it home and into the freezer as fast as possible.

Working From Home