So we made one last batch of soymilk using Laura soybeans and boiling rather than soaking them.
The result was drinkable by itself although the taste is not as “rich” as the commercial product. It has a rather bland taste but its not the unpleasant beany taste that we experienced up to this attempt. We added a pinch of salt and sweetened to taste with homemade fake maple syrup. We also added a dash of natural almond extract. We weren’t attempting to make the soymilk sweet but rather to add taste. The salt, syrup, and almond extract added taste that masked the original taste. I’d probably try it without almond extract next time or, at least, less.
I’m pretty sure that the difference results from the type of beans used. From Sensory quality of soymilk and tofu from soybeans lacking lipoxygenases:
The oxidation of unsaturated lipids by lipoxygenases in soybeans causes undesirable flavors in soy foods. Using a traditional and a nontraditional soy food user group, we examined the cultural difference in perceiving the sensory characteristics of soymilk and tofu produced from soybeans with or without lipoxygenases. [O]ur results demonstrated that soybeans lacking lipoxygenases can produce soy foods with less undesirable aromas and are therefore likely more acceptable to the consumers.
We did another test using the same beans that we had been using before where we boiled the beans instead of soaking them. We didn’t report on the results because there was little or no improvement in taste. Although I can’t be sure, Laura beans must be one of the low or null-lipoxygenase varieties. They may also be vegetable type rather than field type beans. The vegetable type have a slightly nutty flavour. When we first received the Laura beans, we dry roasted them and noted a wonderful nutty taste. Other beans that we roasted did not have that nutty taste and actually needed salting for flavour.
If vegetable type beans such as Laura beans (and boiling rather than soaking) are the secret to good soymilk, then let the search for more vegetable varieties begin. It should be an interesting search because most of the soybeans grown are for animal feed and processed food additives.