Don’t you just love those bright pink onions on your tacos? (And also the escabeche of hot peppers, carrots, radish, etc. common to Mexican restaurants?) I’ve been asked how to get that really striking shade of pink before and the answer is simple.
Besides using red onions, for a real color boost, you also need to add some or all of the peel to your jar. That’s it! You also just need to allow enough time for the tannins to be released into the liquid medium, which could take upwards of a week.
Besides being attractive, red onions are full of flavor, and rich in antioxidants and other vitamins and minerals. The tannins from the peel will only add to this nutritional and flavor profile. In my easy recipe below, I add a pinch of other seasonings and hot peppers to deepen the flavor a bit further, but this is optional.
Since you don’t want little bits of peel stuck to your onion slices, your best bet is to cut off the tops and bottoms of your red onion, peel kept on, and include those in your jar. I don’t just mean cutting the very ends, but rather cut to about a 3/4″ length, so that sufficient peel is retained.
Instead, or in addition, if you want an even brighter pink color, if you can keep entire the peel in one or two large pieces, it can go in the jar. (If it’s breaking into many little pieces, just using the ends of the onion is a better way to avoid bits of peel in your onions.)
Place the onion peels, tops, and bottoms strategically in your jar. This means, at the very bottom or top, not haphazardly mixed up with the rest of the sliced onion.
If placed at the top, they can all be removed when you’re happy with the color and ready to start using the onions. If placed at the bottom, they’ll just stay there until all the onion is used up, and during that time, they can continue to release a little extra color and flavor. But there isn’t much difference in the two so just pick one :).
My last bit of guidance is to pickle your onions however you want. This means they could be quick vinegar pickled, lacto-fermented (meaning fermented in saltwater, explained below), or even canned. Regardless of the liquid, the red tannins will be released.
In vinegar pickling, a fermentation weight is less critical. If some of the onions are exposed to air, simply shake the jar or stir things around periodically. However, in lacto-fermentation, all veggies must be submerged under a saltwater brine while fermenting at room temperature, otherwise there is a strong mold risk. After a week, fermented onions can be transferred to the fridge.
Here is a quick vinegar pickled recipe (updated 12/1/21):
You will need:
- Quart jar
- Knife & cutting board
- Measuring cups & spoons
- Small or medium saucepan (optional boiling of the brine)
- Suggested: canning funnel
- Suggested: fermentation weight
- 1 large red onion (~350-450g), can weigh up to a pound and fit in a quart jar
- 2.5 cups vinegar (or substitute a 1/2 cup vinegar with water)
- 1 bay leaf
- 1 tsp pickling salt
- 1/2 tsp black peppercorns
- 1/2 – 1 tsp sugar (optional)
- Sliced hot peppers (optional) – I used a few slices of Manzano pepper, which is a a fair bit hotter than jalapenos
For fermenting: If you want to ferment the onion instead of vinegar pickling it, use water instead of vinegar and increase the salt to 1 TBSP. Do not heat the brine but rather dissolve the salt in the cold water, pour all ingredients into the jar, close the lid and burp it once a day to release gas buildup. Make sure the onions are totally under the brine using a ferment weight. After about a week, transfer to the fridge. The shelf life will be comparable to vinegar pickled and can stay good for months. Fermented onions made this way are slightly less acidic and have a deep earthy flavor; they are also probiotic.
Vinegar Pickled Directions:
1.) Remove the peel of the red onion and cut off a large section of the top and bottom to retain. If the peel can be kept in a large piece or pieces, also retain it.
2.) Thin slice the red onion into rings. (Or you may halve the onion and then cut into semi-circle slices.) Also ring slice any hot pepper you may want to add.Place the onions in the jar, along with any hot peppers. As discussed above, placing the peel and onion ends at the very bottom or top is suggested.
3.) Bring the vinegar (and any water), salt, sugar, bay leaf and peppercorns to a boil in saucepan. (Or you can skip boiling and cold brine the onions if you prefer them crunchier, but expect to wait longer for a finished product.)
4.) Pour the (hot) vinegar over the onions, optionally using the canning funnel to do so. In order to fully submerge the onions, a fermentation weight may be useful even in vinegar pickling. If you go this route, less brine will be needed (just fill to below the jar’s shoulder, add the weight, and then decide if more brine is needed).
5.) Seal the jar tightly and allow to stand at room temperature for an hour or two. Then place in refrigerator and give ample time for the flavors to meld and color to release. The onions are ready to eat within a day if using hot brine, but waiting several days to a week will give best results. Cold brined onions are best after at least a week. Once you start using the onions, remove the weight.