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Name: Kristin
Status: other
Grade: other
Location: MO
Country: N/A
Date: April 2006

Question:
Why is vinegar used instead of HCL to preserve food?



Replies:
Kristin,

Vinegar is acetic acid and is used because it is a weak acid that our bodies can tolerate. HCl is what stomach acid is mostly composed of and is a very strong acid. If HCl was used, then it would start to decompose the food instead of preserve it!

Matt Voss


There are a number of reasons:

1. Dilute vinegar (3-6% w/w acetic acid) has a more pleasant taste than HCl (assuming it is diluted so as not to be corrosive).

2. Some vinegars used in cooking come from the fermentation of wine. This adds many subtle tastes to the food being preserved that would be absent if HCL were used as a preservative.

3. HCl tastes too "salty".

4. The chloride ion ([Cl](-1)] catalyzes the reaction between HCl and iron, so any iron used in the food preservation (such as a cast iron skillet) at high temperature is subject to faster corrosion, and traces of dissolved iron, which tastes "funny" and discolors some foods, especially those containing sulfur, where iron sulfide is formed (black).

5. Acetic acid is a better buffer than HCl so it tends to have a more stable pH during storage.

Strictly as a microbicide, HCl should work well, it just has a lot of these other issues that limit its use as a preservative. There may be some recipes that call for HCl, but I don't know of any.

Vince Calder


Probrably the simplest method is to tell them how the air must be pushed aside, similar to pushing something through water. The analogy works well enough, with the explination that water is far heavier than air, and it is harder to move heavy things out of the way.

Ryan Belscamper



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