Cucumbers and onions in vinegar is one of those old-fashioned, no-fuss side dishes that shows up at cookouts, potlucks, and family dinner tables for good reason — it’s crisp, tangy, refreshing, and takes only a few minutes to throw together. With just a handful of ingredients, this simple marinated salad is a perfect side for grilled meats, sandwiches, or a summer picnic spread.
Why This Recipe Works
The vinegar-based dressing does double duty: it seasons the cucumbers and onions while also lightly “pickling” them as they sit, giving the dish a tangy bite and a slightly softened, marinated texture. It’s endlessly adjustable too — sweeter, tangier, or spicier, depending on your preference.
Ingredients
- 2 large cucumbers, thinly sliced (English or regular, peeled if desired)
- 1 medium sweet onion (such as Vidalia), thinly sliced
- ¾ cup white vinegar or apple cider vinegar
- ¼ cup water
- ¼ cup granulated sugar
- 1 teaspoon salt
- ½ teaspoon black pepper
- ½ teaspoon celery seed (optional, but classic in many versions)
- 1 tablespoon fresh dill, chopped (optional)
Equipment
- A mandoline or sharp knife
- A large bowl or airtight container
- A small bowl or jar for the dressing
Instructions
Step 1: Slice the cucumbers and onion
Using a mandoline or sharp knife, slice the cucumbers into thin rounds, about 1/8-inch thick. If using regular (non-English) cucumbers, you can peel them fully, partially, or leave the skin on, depending on your preference. Slice the onion thinly as well — a mandoline helps keep the slices even here too.
Step 2: Make the vinegar dressing
In a small bowl or jar, whisk together the vinegar, water, sugar, salt, pepper, and celery seed (if using) until the sugar and salt are fully dissolved.
Step 3: Combine
Place the sliced cucumbers and onion in a large bowl or airtight container. Pour the vinegar dressing over the top, making sure the vegetables are well coated and mostly submerged. Add the fresh dill, if using, and toss gently to combine.
Step 4: Marinate
Cover and refrigerate for at least 30 minutes to let the flavors develop, though the salad gets better the longer it sits — 2-4 hours or overnight is ideal for a more deeply marinated flavor.
Step 5: Serve
Give the salad a quick toss before serving, since the vegetables release some liquid as they sit. Serve cold as a refreshing side dish.
Tips for the Best Cucumbers and Onions in Vinegar
- Slice thinly and evenly so the cucumbers and onions marinate at the same rate.
- Use a sweet onion like Vidalia for a milder flavor, or a red onion for extra color and a slightly sharper bite.
- Adjust the sweetness by increasing or decreasing the sugar to taste — some versions lean more tangy, others more sweet.
- Salt the cucumbers first and let them sit for 15 minutes, then pat dry, if you want a slightly crisper texture with less excess liquid in the final dish.
- Add sliced bell peppers for extra color and crunch, a common variation in some regional versions of this dish.
Storage
Store in an airtight container in the refrigerator for up to 5-7 days. The cucumbers will continue to soften the longer they sit in the vinegar mixture, so they’re best enjoyed within the first few days for the crispest texture.
Final Thoughts
Cucumbers and onions in vinegar is about as simple and reliable a side dish as it gets — a handful of pantry staples, minimal prep, and a tangy, refreshing result every time. It’s the kind of recipe worth keeping on hand all summer long, especially when cucumbers are plentiful.
