Vinaigrette Dressing Exploding..HELP!

This past year the vinaigrette dressing we make using our spice mix, oil & vinegar decides that it will explode if not used in one day which makes a big mess when we wrap salads. Is there some chemical reaction that causes the gas to build inside the plastic soufle cup to the point that it bursts open? We have been doing this for years but only recently has it been a problem. We try to keep them inside the cooler at night and they are stored ny the counter away from heat so I am not sure why the problem persists.

Am I crazy or does this sound familiar to anybody…thanks!

Vinegar can react with baking soda to generate co2 (carbon dioxide) gas. But where is the baking soda or whatever it is coming from?

Try putting the same amount of vinegar and oil into a zip lock sandwich bag and any other small size sealed container overnight and see if you get gas buildup in the other containers.

If you don’t, the gas reaction may be coming from some invisible agent in the cup you are using.

If it isn’t coming from the container, perhaps try a different brand of oil.

Do you add seasonings or spices to the mixture? One of those may be the culprit.

You’re “spot on”. I’m with you, in thinking the vinegar (dilute acetic acid) must be reacting with something. It will react with anything having a pH of more than 7.0 (basic). Your approach is a good one too. Plain cup with vinegar, then, in addition to the vinegar, begin adding any constituent ingredients, one at a time, until you find something that reacts with the vinegar and creates the carbondioxide. It could be just about anything that has a pH above 7.0. If the reaction takes place pretty quickly, you might be able to mix everything together and allow it to set, uncovered for a few minutes allowing time for the reaction to take place, and the carbon dioxide to dissipate, then try covering the cups in the usual manner.
Tom Lehmann/The Dough Doctor