I tried black coffee at 4 fast-food chains, and there's only one I would ever buy again

• I ordered a small, black coffee from four fast-food chains to find the best one.
• The drinks from Sonic, Wendy's, Burger King, and McDonald's all were cheap and convenient.

I drink coffee two or three — OK, sometimes four — times a day and almost exclusively take it black.

Most days, I stick to my Keurig at home, but over the past few months, I've tried iced coffee and signature roasts from different chains.

This time, I ordered hot black coffee from Sonic, Wendy's, Burger King, and McDonald's to see which fast-food giant has the best brew.

I changed my opinion on Sonic's coffee as I kept drinking it

I expected to enjoy this option, as Sonic's Green Mountain coffee is a mild blend, and I have tried the same brand's pods before.

At first, the drink had a pretty rich and fine flavor, but it soon developed a weird aftertaste that was more dry and bitter than I would've liked.

I enjoyed the first two sips, but the shift made me really dislike this option by the end. This was the only coffee that I changed my mind about.

Despite its generous serving size, Wendy's coffee offered very little flavor

Wendy's website describes its regular coffee as a medium roast, but this drink was the bitterest out of all the options I tried.

In addition to its biting flavor, the coffee also seemed somewhat watery, which resulted in an unsatisfying combination.

But I noticed traces of a light hazelnut flavor, which at least made this option taste better than Sonic's.

I got plenty of coffee for a low price, as this drink was the largest of the four, but I wished it had a better flavor that made me actually want to finish it.

The coffee from Burger King was the most disappointing

After surprisingly being handed large servings at Sonic and Wendy's, I was glad that Burger King's version of a small coffee was a manageable size.

Unfortunately, I disliked this drink the most.

This brew had very little flavor and seemed to be both watery and burnt, which did not make for a good combination.

In all fairness, I may have just been unlucky and gotten a burnt cup of what normally would've been decent coffee, but I still wouldn't go out of my way to give this option another chance.

McDonald's coffee was easily my favorite, and I would definitely get it again

About the same serving size as Burger King's, McDonald's small coffee rose above every other option I tried for this taste test — it was exactly what I was looking for.

The chain's coffee had a great, rich flavor that wasn't bitter, making it really smooth even without any milk, sugar, or additional sweeteners.

I didn't like most of the drinks I tried, but there were some positives that every order had in common

Every chain I went to charged less than $2.25 for a small cup of hot coffee, which made each drink a more affordable option than you'd find at high-end shops and restaurants.

If you don't want your coffee black and plan to add syrups and sweeteners, these are all affordable choices.

But if you're looking for a coffee that tastes so good, you'll forget how little you paid for it, then you should definitely check out McDonald's noteworthy cup.