Place the peppercorns and vinegar in a small pan and reduce until nearly dry (smell will be a very strong one). Remove from stove and add water, then strain into a bowl. Add egg yolks into the bowl with the vinegar reduction. Whisk together in a double boiler over simmering water. Cook whisking constantly until eggs are thickened and form ribbons. Gradually add the butter in a thin stream (very thin), whisking constantly until all the butter is incorporated and the sauce is thickened. Remove from heat and season to taste with salt, and pepper/cayenne pepper, and lemon juice. Serve or store warm for up to two hours.