The invention relates to a method of producing a shelf stable ready-to-drink beverage product, comprising the steps of: providing an ingredient composition comprising micellar caseins and whey protein, having a total protein concentration of 1.5 - 8 wt. %, and wherein the composition has a casein to whey protein ratio of 90/10 - 60/40, adding divalent cations to provide a concentration of 3 - 20 mM free divalent cations in the ingredient composition, and 0.025 - 0.3 wt % of a stabilizing system comprising hydrocolloids, and subsequently heat treating the ingredient composition at ultra high temperature (UHT) at 135 -150°C for 3 - 30 s to form agglomerated proteins comprising casein and beta-lactoglobulin from the whey protein, the agglomerates having a size of 5 - 30 microns mean diameter D(4,3) as measured by laser diffraction. The invention also relates to a shelf stable ready-to-drink beverage product comprising aggregated proteins comprising micellar caseins and whey protein aggregates, wherein the product has a pH of 6.6 - 7.2, 1.5 - 8.0 wt. % milk proteins, a casein to whey protein ratio of 90/10 - 60/40, and a concentration of 3 - 20 mM divalent cations, and the aggregates are of 5 - 30 microns mean diameter D(4,3) as measured by laser diffraction.L'invention concerne un procédé de production de boisson prête à boire de longue conservation, comprenant les étapes consistant à : fournir une composition d'ingrédients comprenant des caséines micellaires et des protéines lactosériques, ayant une concentration totale en protéines de 1,5 – 8 % en poids, et la composition ayant un rapport caséine/protéines lactosériques de 90/10 – 60/40, ajouter des cations divalents pour obtenir une concentration de cations divalents libres de 3 – 20 mM dans la composition d'ingrédients, et de 0,025 – 0,3 % en poids de système stabilisant comprenant des hydrocolloïdes, puis traiter thermiquement la composition d'ingrédients à ultra haute température (UHT) à 135 – 150 °C pendant 3 –
