On Salt & Vinegar (and kettle chips)

Hardly a mad science experiment, but more of a gateway process to unhealthy amounts of sodium in my future diet: Salt & Vinegar seasoning for Salt & Vinegar potato chips.

In the theme of science for science’s sake, let’s talk a minute about vinegar. Typical distilled white vinegar you buy at the local grocer is a solution of about 5% acetic acid (CH3COOH), otherwise known as ethanoic acid. Being an acid, its difficult to apply to starchy foods and vegetables without essentially dissolving or denaturing the intended target. It’s challenging to convert into a powder form. One of the more common industrial methods is to spray a fine mist of acetic acid over a fine bed of maltodextrin– a slightly sweet, neutral carbohydrate that absorbs the acetic acid solution. When dried it’s applied with salt to your favorite kettle chips as a souring agent to give that tangy, vinegar bite.

I don’t exactly eschew industrial methods oi my own home kitchen. I mean, I like junk food, I just don’t like paying for it if I can produce it in a small scale at home. If I can steal a bit of industrial methodology to help cut out the middleman, well, I’m not a purist is what I guess I’m saying. Still, sourcing maltodextrin powder, and then figuring out the proper spray ratio, drying times, processing steps, and all that? Nah. There’s an easier way and, while it’s a little more time consuming, it lends an equivalent product for a fraction of the perceived time I’d spend figuring the whole thing out end-to-end, experimenting, dialing it in and then executing it. The easy way uses common, off-the-shelf ingredients, some grade-school science and a little patience. All you need is vinegar and baking soda.

I’m not going to get into the particulars of the redox reaction that happens, but when you take a 5% solution of acetic acid and sodium bicarbonate (ye Olde Vinegar and Baking Soda), you get a solution of sodium acetate, which is one of the souring agents in a number of brands of Salt & Vinegar potato chips.

In ratio, slowly combine 1.2 liters of distilled white vinegar (acetic acid, 5%) with 42g of baking soda (Na2CO3) to get about a 5% solution of sodium acetate (C2H3NaO2). Then you reduce this solution to a supersaturated volume (about 200ml, if using the full volume) and allow it to crystalize. Dry the crystals and pulverize them into a fine powder which, when rehydrated, produces a vinegar flavor on the tongue.

Having performed this experiment at about half scale (750ml of vinegar with a healthy spoolful of baking soda), I note that I got about 2 oz of sodium acetate powder out of the effort, and it did not knock my socks off. It tasted mildly of vinegar and baking soda, but I was not careful with my ratios.

What did knock my socks off was what happened when I combined the sodium acetate with citric acid and table salt. It turns out that some brands of potato chips use citric acid as a souring agent, and sodium acetate for vinegar flavor. Your tongue is fooled into thinking you’re tasting a pungent vinegar powder, but I now know that to be a lie. A tasty, salty lie. I exposed that lie by combining 1 part cittic acid (1 tbsp) with 2 parts (2 tbsp) sodium acetate and 2 parts (2 tbsp) table salt. To taste it straight from the shaker, it’s a little more sour and rather saltier than straight sodium acetate, but to shake it over fresh kettle chips is to introduce a delightful sour/vinegar and salt taste to the chips. You want to go heavier from the shaker than you might think you want if it was straight salt, and then toss it well. Let the flavors meld a bit (if you can keep the “just a taste” crowd away…) and then serve. Should keep up to 3 or 5 days in a paper bag, assuming they stick around that long.

Now for the chips, this was a pretty typical kettle chip recipe. Eastern potatoes sliced ⅛” thick on a mandolin and soaked in a weak brine to draw out some starch. Then deep-fried in handfuls until lightly golden, cooled and re-fried again until golden brown. Finally, the whole batch gets tossed in this citric acid/sodium acetate/table salt mix and served.

I’ve also tried this salt mix on popcorn, roasted Brussels Sprouts and scrambled eggs. It’s always a treat.

Sodium Acetate instructions

  • (In ratio) 1.2 L distilled white vinegar
  • (in ratio) 42g baking soda

Slowly pour vinegar over baking soda in a non-reactive steel or glass vessel, stirring vigorously until the solution stops foaming and bubbling when agitated

Reduce solution to about 1 tenth of the original volume by microwaving in segments, over an alcohol flame, or in an evaporating pan in a warm oven. Do not overcook if heating. Should reduce to a transparent gel that forms crystals when blown. Allow to cool and form crystals. Remove crystals and dry on a clean coffee filter. Use additional coffee filters until fully dry. Pulverize into a fine powder. Should yield 4 oz.

Vinegar Salt instructions

  • 2 oz table salt
  • 2 oz sodium acetate
  • 1 oz citric acid

Citric acid is available in the canning aisle at most grocery stores.

Combine well and store in an airtight shaker.