MirepoixDescribe what you see
Write down whether the sauce is glossy and uniform, excessively thick, visibly oily or grainy. Also note whether the problem appeared during butter addition, after heating, or while holding the sauce.
If the egg has visibly coagulated, restoring a smooth emulsion is not the same as undoing cooked egg. Do not promise that more whisking or an extra ingredient reverses that change.
Change one variable at a time
A very thick but still uniform sauce may need a small, measured amount of suitable liquid. For an emulsion beginning to separate, temperature and the rate of fat addition both deserve attention. Use a method written for that particular sauce rather than a universal spoonful-of-anything fix.
If a recipe describes rebuilding the emulsion in a fresh base, add the broken mixture gradually to that base. Record what you tried; otherwise several additions can leave you with a different sauce whose proportions are impossible to repeat.
Plan the next batch around the failure
Set up a gentler heat source if overheating was the issue. Prepare the butter so that it can be added steadily. Choose a bowl that gives the whisk access to the entire mixture, including the edges.
Serve and hold egg-based sauces according to appropriate food-safety guidance for your ingredients and setting. A sauce looking smooth does not establish that it has been cooked or held safely. This page is a technique discussion, not a temperature-control procedure.
- Check texture before adding more fat.
- Avoid leaving a delicate sauce on uncontrolled heat.
- Keep a note of the sequence, not only the final quantity.