Frozen sweet corn, on the cob and whole kernel
Blanched the same day it was picked, August corn tastes like August in February. Kernels for chowder, a few cobs for a treat.
Makes
About 1 kg of kernels from a dozen average ears; a dozen cobs fills a 4 L freezer bag
Active time
45 minutes
Total
1½ hours including cooling and packing
Before you start
What matters for this one
- Blanching is not optional for corn: 4 minutes for kernels, 7–11 minutes on the cob by size. Unblanched corn keeps freezing but turns starchy and stale within weeks.
- Time from when the water returns to the boil, not from when the corn goes in. Use enough water (4 L per 450 g) so it recovers fast.
- Cool as long as you blanched, in ice water, and drain thoroughly — wet corn freezes as a block with ice crystals through it.
- Freeze no more than will go solid within 24 hours (roughly 1–1.5 kg per 30 L of freezer space at a time), with packages spread out until frozen.
This follows NCHFP: Freezing corn. Quantities, acid and times are theirs; do not scale the vegetables without scaling everything, and do not change the vinegar, lemon juice or processing time.
Ingredients
- Sweet corn picked that morning if you can — it loses sugar by the hour
- A large pot of boiling water: 4 L (1 gallon) per 450 g (1 lb) of corn
- A sink or tub of ice water: about 450 g of ice per 450 g of corn
Method
- 1
Shuck the corn and pull off the silk — the best job in the garden for a child, outside, over the compost. Trim any wormy tips.
- 2
Bring the big pot to a rolling boil. Lower in a few ears at a time without crowding so the water comes back to the boil quickly.
- 3
For corn on the cob, time from when the water returns to the boil: small ears (3.2 cm, 1¼ inches across or less) 7 minutes, medium (3.2–3.8 cm) 9 minutes, large (over 3.8 cm, 1½ inches) 11 minutes. For whole kernel corn, blanch the ears 4 minutes.
- 4
Lift the ears straight into the ice water and leave them there as long as they boiled. Cobs must be chilled to the core or the frozen corn tastes of cob; swap in fresh ice as it melts.
- 5
Drain well. For cobs: pat dry, wrap each in plastic or pack several in a freezer bag, press out the air, seal and freeze. For kernels: stand each ear in a wide bowl and cut down with a sharp knife about two-thirds the depth of the kernel, leaving the tough base on the cob.
- 6
Pack the kernels into freezer bags or boxes leaving 1.25 cm (½ inch) headspace, press out the air, label with the date and freeze flat so they stack.
Keeps: 8–12 months at −18 °C (0 °F) for best quality. Cook kernels from frozen; thaw cobs in the fridge before boiling or they cook unevenly.
Variations: For cream-style corn, blanch 4 minutes, cut just the kernel tips, then scrape the cobs with the back of the knife to get the milk; pack with 1.25 cm headspace. Leftover cobs make a sweet stock for chowder — simmer 30 minutes and freeze that too.
Tested source: NCHFP: Freezing corn. Checked October 2026. If a jar did not seal, refrigerate it and use it within a few days. Never taste anything from a jar that is bulging, leaking, spurting or smells wrong — when in doubt, throw it out without tasting.
The crop
Sweet corn: when to pick, how to store, what else to make →
Freezing within hours of picking is the only way to keep sweet corn tasting like August. For kernels, husk and silk, blanch whole ears 4 minutes, chill in ice water, cut the kernels off at about two-thirds of their depth without scraping the cob, and bag flat — this is the cut corn that goes into every winter chowder. For corn on the cob, blanch by ear size — 7 minutes for small ears under 3 cm across, 9 for medium, 11 for large — and chill thoroughly, or the cob tastes woody; frozen cobs are good but never quite fresh. Canning corn is pressure-canner only, 55 minutes for 500 ml jars and 85 for litres of whole kernels at 10 lb (weighted gauge, 0–300 m), and cream-style corn in 500 ml jars only for 85 minutes; corn is a low-acid vegetable and there is no safe water-bath time. Supersweet varieties can brown in the jar, so can a small test batch first. Blanched kernels also dry well for soup.