Some recipes suggest leaving out the bicarbonate of soda for fear that it affects the flavour of the peas. Having tested this recipe numerous times, I can confirm that the bicarb does not adversely affect the flavour of the peas, provided they are well rinsed after soaking. The bicarb does help soften the peas though, leading to a significantly lower cooking time and a better texture. In fact, the difference was so much that I would not attempt to make a mushy pea recipe without it again.