HeySolids
Choking risk
As a liquid flavoring used in tiny amounts, vinegar is a low choking risk.
Never give vinegar neat or off a spoon, since it is very acidic and can sting the mouth; stir a small splash into food instead. See how to serve for age-by-age prep.
Allergens
Vinegar is not a common food allergen, so a true allergy to it is rare.[1]
Most vinegars are distilled and made from apple, grape, or rice, so they carry no allergen concern.
Malt vinegar is the exception: it is made from barley and is not distilled, so it contains gluten. Barley is not on the US label list, so it will not appear in bold - read the ingredient list if your family avoids gluten.
Food safety
Vinegar is acidic and can wear at tooth enamel, so keep it to a small splash mixed into food rather than anything your baby sips or eats on its own. Never add sugar to take the edge off the sourness - children under 2 don't need added sugar.[2]
Pickles, bottled sauces, and most vinegary condiments are heavily salted, so the salt tends to arrive with the vinegar rather than from it. Use plain vinegar in your own cooking instead. Don't add salt to food in the first 12 months, and keep it low through the toddler years.[2]
How to serve
6-24 months +
A splash in cooking
Vinegar can go into your baby's food from the start of solids, in the small amounts you'd use in cooking. A few drops in a lentil dish, a braise, or a tomato sauce lifts the flavor without adding salt. Cook it in rather than adding it at the end, so the sharpness softens. Skip pickles and bottled vinegary sauces, which carry a lot of salt with the vinegar.
How to cook
Use plain vinegar - cider, white wine, rice, or red wine all work. Add it early so it cooks down with everything else. Balsamic is sweeter and suits slow-cooked dishes, but check the label, since cheaper ones often have added sugar.