I am doing some research for my next blog post. The topic is making vinaigrette in small batches as an alternative to buying the bottled variety off the shelf. I use a premium EVOO and store the batch in a glass carafe with a pouring spout. I keep both the opened bottle of olive oil and the carafe in the frig, then re-emulsify the vinaigrette just prior to use. I finish the carafe over the course of a couple of weeks and make up another batch. I just feel much more comfortable refrigerating this product for a whole lot of reasons. But in your opinion and expertise, is refrigeration necessary for either the vinaigrette or the opened bottle of EVOO?
I have been doing the same thing at home for many years, as I was born in France where, when I grew up, there was no such thing as bottled vinaigrette in a store.
First, there is no advantage to refrigerating olive oil. You want to keep it in a cool spot, away from light, but refrigeration won't provide additional preservation benefits. You should know, however, that once a bottle of olive oil is opened, it does loose some of its flavor and health benefits pretty rapidly, because of oxidation. This is true once it is in the vinaigrette as well.
What you are doing -- only opening the bottle of olive oil every couple of weeks -- is very good, because you are not constantly introducing oxygen in the bottle. If you want to go even further, you could spray a little bit of inert gas in the bottle each time you open it. You can find inert gas in any wine store or in our boutique: http://boutique.oliveoilsource.com/content/can-inert-gas
If you want to go yet a step further, buy a stainless steel container with a spigot at the bottom. Buy bulk olive oil to fill it. It is quite economical in the long run and is the best way to preserve olive oil from light and oxygen. It will pay for itself after the equivalent of 10 to 12 bottles. You can see some stainless steel fusti at: http://boutique.oliveoilsource.com/browse/for-the-home/503 .
Although there is no need to refrigerate a vinaigrette with oil and vinegar only, you should refrigerate any vinaigrette with additional ingredients: mustard, garlic, shallots, etc…
Please let me know if you have any other questions.
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