Rubio’s Coastal Grill is known for bringing delicious Baja fish tacos to the US, and their signature Rubio’s white sauce recipe is an important part of the recipe. It’s so simple but too many people overcomplicate it. Four ingredient is all it takes. Mayonnaise, plain yogurt, fresh lime juice, and a pinch of salt. No hidden spices or secret herbs to discover. Here’s how you make it.
The founder of Rubio’s Coastal Grill was Ralph Rubio. He used to surf down in Baja and always loved finishing the day with a fresh fish taco from one of the street vendors. Fried fish on a warm corn tortilla, topped with a fresh salsa, crispy shredded cabbage, and a tangy and creamy white sauce that provided a fantastic contract to the spice and the crunch.
I speculate the vendors in Mexico were using crema, a naturally tangy version of sour cream that is a little thinner than what we’re used to in the United States. Today, in most markets you can find a squeezable bottle of crema but back in 1983 when Ralph Rubio opened up in Mission Bay, just down the street from my high school, he likely didn’t have real Mexican crema so he made it himself. I don’t have any documented proof of that, but from what I know about authentic Mexican food, that would be my guess.
It’s simply equal parts mayonnaise and plain yogurt, brightened a touch with a squeeze of fresh lime and a pinch of salt. Some have suggested using Greek yogurt instead of regular plain yogurt, but back in 1983 that wasn’t as readily available either. I do regularly make my fish taco white sauce with greek yogurt and it works out great.
You’ll find a lot of recipes calling for dill, capers, cayenne pepper, and other ingredients. I know those all taste great and you’ll find them in plenty of restaurants, but if you’re looking for something that tastes exactly like Rubio’s fish taco sauce, this is it. It’s a beautiful blend of creamy, tangy, and citrus, all allowed to rest for a couple hours and then topped on your Baja fish taco or whatever else you’d like. I love it all sorts of tacos and burritos.
Rubio’s White Sauce
Ingredients
- 1/2 cup mayonnaise (Recommend: Best foods or Hellman's)
- 1/2 cup plain yogurt, whole-milk
- 1 Tbsp Fresh lime juice (Add slowly and taste)
- 1 pinch fine salt
Method
- Combine mayonnaise and plain yogurt in a bowl. Whisk until completely smooth with no streaks.
- Add lime juice slowly while whisking. The mixture will thin slightly.
- Add cold water, one teaspoon at a time, until the sauce holds its shape but drizzles easily. Not runny, not thick like straight yogurt.
- Add a pinch of salt. Stir to combine.
- Transfer to an airtight container or squeeze bottle.
- Refrigerate at least 2 hours. Overnight is best.
- Stir or shake before serving.
Pro Tips for Rubio’s White Sauce Recipe
Use the Right Mayonnaise
Best Foods or Hellman’s here on the East Coast is really the gold standard for everything that takes mayo. Dukes is a great alternative, but growing up in San Diego, I know the best in our grocery stores was Best Foods. Hellman’s is the exact same mayo. The manufacturer just uses different brand names on each coast. Make sure you don’t try going light on this with a low or no fat version and absolutely do not use Miracle Whip. This is half of the recipe so don’t skimp.
Plain Yogurt Works Best
In 1983, you didn’t see Greek yogurt in regular grocery stores and I doubt Ralph Rubio used it in his fish taco white sauce recipe. The key is to use plain unflavored and unsweetened yogurt. Be careful you don’t grab the vanilla or another flavor. If you do have Greek yogurt, feel free to try it out, but you’ll likely need to dilute it a little more for it to drizzle properly.
Fresh Lime Juice Only
Do yourself a favor and use fresh limes for you lime juice in this recipe. You’re going to need fresh limes to serve in wedges with each taco anyway, so take half of one and squeeze out a couple teaspoons to make sure you get a true copycat Rubio’s white sauce on your fish tacos. It’s brighter and cleaner tasting that anything you can get pre-squeezed.
Give It Time to Rest
The best fish taco white sauce is going to need time to settle and bring the flavors together. I recommend at least two hours, but it’s even better if you let it sit in the fridge overnight. You’ll notice the difference.
Prevent Separation
Start with a cold bowl and cold ingredients straight out of the refrigerator. Room temperature may o can break when the acid from the lime hits it. Add the lime juice slowly while whisking it. Take your time and you’ll keep your white sauce from breaking the ingredients. If you do see it start to separate, a good vigorous whisking will typically bring it back together.
Frequently Asked Questions
Storing Rubio’s White Sauce
You can store your fish taco white sauce in your refrigerator in an airtight container or squeeze bottle for 5 to 7 days. It may thicken a bit over time as the yogurt sets, but a simple shake or store and it will be right back to the right consistency.
I don’t remember you try freezing is as dairy based sauces like this can separate and tend to become very grainy when frozen and thawed. The creamy texture you love will never recover.
You’ll find that the flavor holds very well for about 3 days and then it will start to lose some of the brightness you get from the fresh lime juice. It should still be safe unless it smells “off.” It so easy to make, if that happens, just whip up a new batch.
