Sorry, I don’t know as I’ve never made nacho cheese sauce.
Maybe this Reddit post will help you? Sorry if it doesn’t and if that’s the case maybe another HO member can help you.
https://www.reddit.com/r/Foodhack/comments/mdplk6/make_your_own_sodium_citrate_for_instant_cheese/
I feel dumb. I missed your remark about “utilize the citric acid by mixing it with baking soda”, then I ran across this Stop 0:26 / 0:57 Homemade sodium citrate = smooth cheese sauce
That’s the solution vs spending on expensive Sodium citrate.
Thanks so much 
Thanks for that link as well! Big help.
My pleasure.
Just thought I’d let you know, I just made it, and it’s was by far the best result I’ve ever had with a cheese sauce, which means it did not break. Silky smooth. Added some dehydrated jalapenos and dehydrated carmelized onions.
Big shout out to science, and the video authors. In the past so frustrating when you follow a recipe, and time after time it just doesn’t come out exactly the way you want it. Not horrible necessarily, but not at it’s best.
I’m so glad it worked out for you with the results you were looking for!
