Although in the US only Sauce Hollandaise is taught as and considered one of the five mother sauces, this is simply wrong. While they are similar in theory, they are totally different in practice. Neither can be derived from each other and have altogether different characteristics.
Sanitation is of utmost importance when making emulsified butter sauces .
All utensils used in the preparation need to be thoroughly sanitized. Keep on a brick, above water bath and stir frequently. Make sure the sauces are at proper consistency. Make sauce as close to serving time as possible and do not keep for longer than 3 hours. 2 hours is preferred.