TempoLife › Features › Home preserving: freezing, pickling, fermenting and jam › cucumber
Cucumber
The cucumber is the food this whole family of methods is named after in three languages, and it is also the one that teaches the difference between the two acid routes. A fermented cucumber and a vinegar cucumber look identical in the jar and are made in entirely different ways. Nothing else here rewards freshness more: a cucumber picked this morning makes a crisp pickle, one that spent a day in a warm shop makes a hollow one.
The season
Field cucumbers come in a rush from mid-July to the end of August. Pickling varieties are picked small and firm, and the difference between a good and a poor jar is often only how many hours old they are.
Acidity decides the method
Fresh cucumber is low-acid, around pH 5.1–5.7. Both preserving routes exist to fix that: fermentation makes acid, vinegar adds it.
This is a reference guide, not a recipe authority and not medical advice. The one organism the safety rules here are written against is Clostridium botulinum, and the one way to be protected against it is a tested recipe followed exactly — substitutions of the acid, the sugar or the salt are not cosmetic. Where the national food authority publishes advice for a specific food (Baltic fish, wild mushrooms), that advice outranks this page.
Method by method
| Method | Verdict | The note |
|---|---|---|
| Freezing | No | Raw cucumber cells collapse completely on thawing. What comes out is grey water. |
| Drying | Poor | Possible as crisps, pointless as a preserve. |
| Fermenting | Best | Whole in a 3.5–5 % brine — 35–50 g salt per litre of water — with dill crowns, garlic and tannin leaves. |
| Pickling in vinegar | Best | Vinegar brine at a tested ratio, hot-packed, water-bath processed for a shelf-stable jar. |
| Jam and sugar preserves | No | Not a jam fruit. |
| Water-bath canning | Good | The finishing step for both routes once the jar is acid — never for fresh cucumber. |
| Pressure canning | No | Heat that high destroys the texture entirely, and the acid routes make it unnecessary. |
| Curing and salting | OK | Dry-salting is the first stage of some fermented recipes rather than a method of its own. |
| Smoking | No | No tradition and no benefit. |
| Root cellaring | Poor | A cucumber is 95 % water and does not store; it wants 10–12 °C and lasts a week or two at best. |
The classic preparation: Brined cucumbers — hapukurk, suolakurkku, solyonye ogurtsy
Pack small firm cucumbers upright into a jar or crock with a flowering dill crown, several peeled garlic cloves, a piece of horseradish root or a horseradish leaf, and blackcurrant, oak or cherry leaves for their tannin, which is what keeps them crisp. Make the brine by weight: 35 to 50 g of plain salt per litre of water, dissolved cold. Pour over so everything is covered, weight the cucumbers down, and leave at 18–22 °C. They cloud and fizz within a couple of days. Half-sour and still crunchy at three to five days, they can move to the fridge then; left three to four weeks they go fully sour and keep for months in the cold. There is no vinegar anywhere in this recipe — adding it would end the fermentation before it began.
Preparation that matters
Wash and, above all, trim about a millimetre and a half off the blossom end of every cucumber — the end away from the stalk. That end carries an enzyme that softens pickles, and this single step is the difference between a crisp jar and a limp one. Soaking the cucumbers in ice water for a few hours before they go in firms them further. Use pickling varieties: short, warty, thin-skinned. A long salad cucumber is bred for a different job and pickles hollow.
What the preserve is worth
A cucumber is not a nutritional heavyweight in either form — around 15 kcal per 100 g raw. What preserving changes is the sodium: a brined or vinegar pickle carries a meaningful amount of salt, and a bowl of pickles is best counted as a condiment. The fermented version at least does not lose vitamins to heat, and the brine itself is a traditional drink in the eastern Baltic for the same reason people drink sauerkraut juice.
The ways this goes wrong
- Leaving the blossom end on, which softens the entire jar.
- Using shop cucumbers waxed for shelf life; the wax blocks the brine.
- Cucumbers that bob above the brine and go mouldy at the top.
- Confusing the two methods: putting vinegar into a ferment, or expecting a vinegar jar to sour over weeks.
Safety rules, temperatures, blanching times, headspace and the pH 4.6 line: USDA Complete Guide to Home Canning and the National Center for Home Food Preservation guidance (US Government / land-grant publications, public domain). Acidity classes: the FDA's published approximate-pH tables. Jam composition: Directive 2001/113/EC. Fish freezing before raw or lightly cured use: Regulation (EC) No 853/2004, Annex III. Checked 2026-09-06.
Sources for this food
Frequently asked questions
How much salt for brined cucumbers?
Between 35 and 50 grams of plain salt per litre of water — a 3.5 to 5 % brine. The stronger end ferments more slowly and keeps longer; the weaker end sours faster and wants the fridge sooner.
Why are my pickles soft?
The blossom end is the usual culprit — trim 1.5 mm off it. After that: cucumbers that were not fresh, a brine that was too weak, or a store that was too warm.
What do blackcurrant or oak leaves do?
They add tannins, which inhibit the enzymes that soften a pickle. It is the traditional answer to the crispness problem and it works.
Related pages
All foods compared
The full table, season by season, with the classic preparation for each.
Nutrition figures
The published USDA row for this food, per 100 grams.
When to sow and harvest it
The sowing calendar entry for this crop in this climate.
How long it keeps fresh
Fridge, freezer and pantry days for this food before it is preserved.
From the garden to the log
TempoLife counts the berries you picked and the jam you ate from them, so the season's work shows up where it belongs.