Half-and-Half with Butter (Best Option)
3/4 cup half-and-half + 1/4 cup melted butter per 1 cup heavy creamHalf-and-half combined with melted butter approximates the fat content of heavy cream (around 36-40%), which is crucial for emulsification and preventing curdling in acidic tomato sauce. The butter adds the necessary fat that half-and-half alone lacks.
To ensure success, whisk the butter into the half-and-half thoroughly before adding to the sauce and add it slowly over low heat to avoid breaking the emulsion. Avoid boiling after addition to maintain smoothness.
The final sauce will be very close in texture and richness to one made with heavy cream, preserving the creamy mouthfeel and balanced flavor without thinning or curdling.