Malva pudding recipe containing too much bicarb and vinegar?

I tried making Malva pudding today using this recipe and the results were decidedly off. I don't know if it was too acidy or basey but definitely didn't taste right. The recipy calls for 2tsp bicarb and 1tbsp vinegar. I did think it was quite a bit of vinegar at the time but trusted the recipe. I assumed the bicarb/vinegar would neutralize eachother and act as a rising agent.

Is this a usual amount of bicarb/vinegar to use in a recipe of this size? Or did I do something else wrong?

Full disclosure: I didn't have jam so that was excluded but followed the recipe faithfully otherwise, fresh ingredients and all. Could the exclusion of the jam have made a diff? I didn't think it would?