It looks like he was developing some sort of nutritional "wafer." I remember when Rob Rhinehart was in the early days of developing soylent, he commented that s

It looks like he was developing some sort of nutritional "wafer." I remember when Rob Rhinehart was in the early days of developing soylent, he commented that some of the raw nutritional powders he was sourcing for the mixture could be quite harmful if taken in the wrong dosage. Maybe he made himself sick with a bad batch of wafers?