Co-digestion of high energy wastes such as casein whey is a cost effective option for boosting biogas production from municipal anaerobic sludge digesters. This paper addresses three challenges to enable full scale application: (i) seasonality of casein whey production, (ii) slow start-up time and (iii) the large amount of manure used as a digestion aid. It is shown that casein whey, with manure as a digestion aid, can boost biogas production by 78% compared to digesting primary sludge alone. Seasonality of whey production can be overcome via ambient storage. While storage results in slightly lower specific biogas yield, it allows year round utilisation of casein whey. It was found that the digesters could be started at a primary sludge: whey: cow manure ratio of 100:50:10 for fresh whey and 100:70:10 for stored whey. These loadings of whey are much higher than previously reported for cheese whey which greatly reduces the time to reach full capacity. The volume of cow manure required to maintain a stable reactor was found to be as low as 1% of the amount of primary sludge which brings the cow manure requirements to a more viable level for full scale applications.