Ice cream keeps about 6 months in the freezer at 0°F (−18°C).
6 months
That's the longest window published for Ice cream — in the freezer is its best case.
Source: USDA FoodKeeper v128 · Spoilage signs: University of Guelph, Ice Cream Technology e-Book (H. Douglas Goff) and Iowa State University Extension and Outreach (AnswerLine) · Category: Frozen foods
How long Ice cream keeps
Situation
Keeps for
Freezer
6 months
Only situations with a published figure are listed. A blank isn't “forever” — it means no reliable number is published for it.
Storage
Store at: Keep frozen at 0°F (−18°C) until you're ready to use it
Refrigerate after opening: Optional — mainly for quality, not safety
Published storage guidance for Ice cream, from University of Guelph, Ice Cream Technology e-Book (H. Douglas Goff):
Temperature swings — not age — are what ruin the texture“It is heat shock, large temperature fluctuations, which is the greatest culprit to the loss of these small, uniform ice crystal size distributions and resulting coarse, icy texture.” — University of Guelph, Ice Cream Technology e-Book (H. Douglas Goff)
Specific to Ice cream, published by University of Guelph, Ice Cream Technology e-Book (H. Douglas Goff) and Iowa State University Extension and Outreach (AnswerLine):
Coarse, icy texture — the most common way ice cream goes off“The most frequently occurring textural defect in ice cream is the development of a coarse, icy texture. Iciness is also the primary limitation to the shelf life of ice cream and probably also accounts for countless lost sales through customer dissatisfaction with quality.” — University of Guelph, Ice Cream Technology e-Book (H. Douglas Goff)
Gritty, sandy bits that do not melt in your mouth“Sandy texture: One of the most objectionable texture defects but easiest to detect. It is caused by Lactose crystals, which do not dissolve readily and produce a rough or gritty sensation in the mouth. This can be distinguished from “iciness” because the lactose crystals do not melt in your mouth.” — University of Guelph, Ice Cream Technology e-Book (H. Douglas Goff)
A dry grey surface or thick ice crystals on top“Have you opened some frozen food to find it has a dry, grayish surface or lots of ice crystals clinging to the surface?” — Iowa State University Extension and Outreach (AnswerLine)
The first list is quoted from University of Guelph, Ice Cream Technology e-Book (H. Douglas Goff) and Iowa State University Extension and Outreach (AnswerLine), with the page each line came from linked beside it; the rest are the general signs for frozen foods. Never taste something to test it — when in doubt, throw it out.
Air and warmth are what shorten an opened item's life — the right container buys back the days the packaging gives up once the seal's broken.
About 6 months, according to USDA FoodKeeper v128, stored as follows: keep frozen at 0°F (−18°C) until you're ready to use it.
Does Ice cream need to be refrigerated?
Ice cream is shelf-stable at room temperature: keep frozen at 0°F (−18°C) until you're ready to use it. Refrigerating it mainly preserves quality rather than safety.
How can you tell if Ice cream is bad?
Coarse, icy texture — the most common way ice cream goes off; Gritty, sandy bits that do not melt in your mouth; A dry grey surface or thick ice crystals on top; A noticeable off taste and smell once freezer burn is bad. That guidance is published for Ice cream by University of Guelph, Ice Cream Technology e-Book (H. Douglas Goff) and Iowa State University Extension and Outreach (AnswerLine). Beyond that, the general signs for frozen foods are: Heavy ice crystals or freezer burn; Dry, discoloured, or leathery patches; An off smell once thawed; A package that clearly thawed and refroze. Never taste something to test it — when in doubt, throw it out.
Can you freeze Ice cream?
Yes — USDA FoodKeeper v128 gives about 6 months in the freezer at 0°F (−18°C). Frozen food stays safe indefinitely; that window is about quality, not safety.