Storing ice cream and what to do when it melts

What temperature to store ice cream at, how long homemade and shop-bought ice cream keeps, and why melted ice cream shouldn’t be refrozen.

Ice cream in the freezer doesn’t look as though anything bad is happening to it. While it stays frozen, bacteria don’t multiply in it. Its texture does change, though: over time smooth ice cream turns icy or grainy. And if ice cream melts and is refrozen, a hygiene risk is added to the poorer taste.

What the right temperature is

Both Slovak Decree No. 82/2018 Z. z. and Czech Decree No. 397/2016 Sb. require frozen creams (the legal term for ice cream) to be stored at −18 °C or below. The Czech decree allows a brief rise to no more than −15 °C during transport. For a home freezer, −18 °C is a good target – most three- or four-star freezers reach it.

Did you know?

According to the textbook by H. D. Goff (University of Guelph), ice cream is only stable – that is, with no growth of ice crystals – below about −25 °C. Above this limit the crystals grow, and the warmer it is, the faster they grow.

So a home freezer only partly “preserves” ice cream. Every week of storage leaves a small mark on the texture.

The greatest enemy: fluctuating temperature

Goff names temperature fluctuation during storage as the main cause of an icy texture. Each time the ice cream warms up, the smallest ice crystals melt. When the temperature drops again, the water doesn’t form new small crystals but freezes onto the larger ones. You then feel the large crystals on your tongue as ice.

The temperature fluctuates when:

  • you open the freezer often,
  • the freezer defrosts automatically,
  • you carry ice cream home from the shop in the warm for a long time,
  • you leave the open tub on the table throughout the meal.

Tip

Put ice cream for longer storage at the back, against the wall of the freezer. The door is the warmest spot. David Lebovitz recommends it when you want ice cream softer for quick scooping – but it isn’t suitable for weeks of storage.

How to store homemade ice cream

  1. Harden it in a shallow metal container in the coldest part of the freezer. A larger surface area and metal speed up freezing, so the crystals stay smaller (Goff). Glass can crack in the freezer.
  2. Cover the surface. Cling film pressed directly onto the ice cream or a tight-fitting lid limits drying out and frost. The National Center for Home Food Preservation recommends wrapping an opened container in film.
  3. Don’t fill the container right to the brim, but don’t leave a large air gap either – air above the ice cream encourages frost on the surface.
  4. Label the container with the date.

How long it keeps

There is no single “shelf life of ice cream”. Goff writes that depending on the conditions it can be anything from a year to two weeks. As a rough guide:

TypeHow long (quality)Source
Shop-bought, unopenedaccording to the date on the packmanufacturer
Shop-bought, openedabout 1 month at most, then rewrapNational Center for Home Food Preservation
Shop-bought, in the freezer generally2–4 monthsUSDA/FMI Food Keeper
Homemadeideally 1–2 weeks (indicative, not an official figure)derived from NCHFP and Goff

According to the National Center for Home Food Preservation, homemade ice cream can’t be stored for long because it turns grainy over time. Industrial ice cream contains added milk solids and stabilisers that slow down crystal growth. These periods concern taste and texture, not safety.

Tip

Make homemade ice cream in smaller batches that you’ll eat within a few days. It’s best on the day it’s made, after a few hours of hardening.

Before serving: tempering

Ice cream straight from −18 °C is too hard to scoop, especially homemade ice cream with less sugar. Leave it for 5–10 minutes at room temperature or move it to the fridge for a while (Lebovitz). Then scoop, and put the rest straight back in the freezer – not after dessert.

Don’t refreeze melted ice cream

Slovak Decree No. 82/2018 Z. z. explicitly prohibits placing on the market frozen creams that have been thawed and refrozen. The Czech Agriculture and Food Inspection Authority (Státní zemědělská a potravinářská inspekce, SZPI) advises against buying ice cream that has clearly thawed, is misshapen or has frost on it.

There are two reasons:

  • Texture. When it melts, the small crystals disappear, and when it refreezes, large ones form. The ice cream will be icy and the change can’t be undone (Goff).
  • Hygiene. A melted mix is moist, sweet and contains protein – an ideal environment for bacteria. In 2024 Slovakia’s Chief Hygienist warned that repeatedly frozen ice cream can cause digestive problems, especially in children and older people.

Warning

If ice cream melts (a power cut, or forgotten on the table), don’t refreeze it. If it was only melted briefly and is still cold, you can use it straight away – in a milkshake, for example. Otherwise throw it away.

How to recognise ice cream that has thawed and been refrozen

  • frost or ice crystals on the surface and inside the pack,
  • the ice cream has pulled away from the sides of the pack or “shrunk”,
  • a misshapen pack, ice lollies stuck together,
  • a hard icy layer at the bottom and lumps.

Summary

  • Store at −18 °C or below, at the back of the freezer.
  • Open the freezer as little as possible and don’t leave ice cream on the table.
  • Cover the surface with cling film or a tight-fitting lid.
  • Eat homemade ice cream fresh, ideally within 1–2 weeks.
  • Don’t refreeze melted ice cream.

Sources

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