The Horsey Sauce I Make Instead of Buying It

Nobody orders a roast beef sandwich for the roast beef. The sauce is the point. Arby’s worked that out a long time ago, which is why you can buy theirs by the bottle.

I found a copycat online a while back, made it once, and stopped buying the bottle. Five minutes, one bowl, no cooking. The recipe is not the interesting part though. The label on the real thing is.

What is actually in the bottled kind

Here is what is in a bottle of Arby’s Horsey Sauce:

Soybean oil, water, high fructose corn syrup, distilled vinegar, corn syrup, modified cornstarch, egg yolk, salt, horseradish powder, mustard flour, natural flavor, sodium benzoate, calcium disodium EDTA.

Thirteen items. Two of them are corn syrup, which is a decision somebody made on purpose and then made again. And the horseradish is powder, which explains a lot about why the bottled version tastes like the concept of horseradish rather than horseradish.

I am not going to tell you the homemade one is health food. It is a cup of mayonnaise. What I will tell you is that it has five ingredients instead of thirteen, it uses the real root, there is no corn syrup in it, and you get to pick the oil. On this site that last one is usually the whole argument, and I have written about why the oil matters more than once.

The recipe

That hour is the only instruction that matters and it is the one everybody skips. Straight out of the bowl the sauce tastes like five separate things sitting next to each other. An hour later it tastes like one thing.

The vinegar is the whole trick

There are a lot of versions of this recipe and most of them are mayonnaise, horseradish, sugar and salt. The one I landed on adds a tablespoon of distilled vinegar, and that tablespoon is the difference between horseradish mayonnaise and the sauce you actually remember.

It sharpens everything behind it. Without it the sauce is perfectly nice and slightly flat, and you spend the whole sandwich trying to work out what is missing. With it, the horseradish arrives on time.

If you only take one thing from this page, it is that the recipes leaving out the vinegar are leaving out the reason you liked it.

About the mayonnaise

This depends on the day for me. When I have made a batch of my own there is no question, because homemade mayo takes about a minute with a stick blender and it is better than anything in a jar. When I have not, I use the Primal Kitchen avocado oil one, which is the jar I keep for exactly this reason.

Either works. Both are honest answers. What I would avoid is the standard supermarket mayonnaise, because then you have swapped a bottle of soybean oil sauce for a homemade version of soybean oil sauce, and you have done washing up for nothing.

About the horseradish

I used the prepared kind, grated, out of a jar. It was great, and the amount above assumes it.

Grate the fresh root instead and you get a better sauce, but do not keep the same amount. Prepared horseradish is cut with vinegar and salt, so fresh runs roughly twice as hot. Start with about half, which is a tablespoon here, then taste it and go up. Brands vary more than you would expect, so treat any number including mine as a starting point rather than a rule.

One warning that applies either way: horseradish fades. An open jar at the back of the fridge from last winter will do almost nothing, and you will end up adding four tablespoons of a sauce that has already given up.

What I use

Quick questions

How long does it keep?
About a week in a covered container in the fridge. Mine never gets that far, but a week is the number I would work to.

Is this actually healthier than the bottle?
It is still mayonnaise, so I would not oversell it. What is true is that you have swapped thirteen ingredients for five, dropped two corn syrups and a couple of preservatives, replaced powdered horseradish with the real thing, and chosen your own oil. Whether that adds up to healthy depends on how much of it you eat.

Can I use Greek yogurt instead of mayo?
You can, and it will be a good sauce, but it will not be this sauce. The bottled version is mayonnaise based and so is the flavor you are chasing. Half and half is a reasonable compromise if you want it lighter.

What else is it good on?
Roast beef is the obvious one. It is also very good on burgers, with roast potatoes, and as the thing you dip a steak fry into when nobody is looking.

Do I have to use sugar?
A tablespoon across a whole cup is not much, and it is doing a real job of rounding off the horseradish. You can cut it to a teaspoon and the sauce still works. Take it out entirely and you have made a horseradish cream, which is nice, but it is a different condiment.