To stimulate sustainable innovation, the MLP, and the governance strategies based on it (like SNM and Transition Management), provide a number of useful tools. For the agricultural sectors, however, with its multi-variety of relevant sustainability aspects and its wide range of 'bottom-up' innovation initiatives by entrepreneurial farmers, these approaches have serious shortcomings. To address this, we have developed a 'Learning and Experimentation Strategy' (LES) in which a novelty is indicated with the term 'promise'. The term expresses that a novelty has attractive features from a certain sustainability perspective, but it has also problematic or unknown sides. Importantly, LES not only looks at individual promises but at a whole range, called the 'portfolio of promises'. Several of these may be connected as 'smart combinations' to address a wider range of sustainability aspects. The PoP as a tool is basically a database that contains information on a variety of aspects for each promise. The paper describes four tests that we have carried out with this tool in the animal production sector. This has led us to refine the strategies for using the LES approach as well change the architecture of the PoP to tune it to various specific applications. Although this is still work in progress, the tests indicate that the PoP can be used successfully as a tool in stimulating innovation towards sustainability.