Background
This experiment explores methods for producing a less beany-flavored soy milk by pre-heating soybeans to denature lipoxygenase enzymes. Five batches of soybeans (100g each) were tested using different pre-treatment methods: dry roasting for varying durations, blanching in boiling water, and blanching with the addition of baking soda to help neutralize flavors and break down the hulls.
Recipe
Ingredients
500g Soybeans (divided into 100g batches)
Water (for soaking and blending)
0.25% Baking Soda (by weight, for one batch)
Equipment
Blender
Strainer or Nut Milk Bag
Pot
Kitchen Scale
Instructions
-
Pre-treatment
Prepare the five 100g batches of soybeans using their respective pre-treatment methods:- Batch 1: Dry roast for 2 minutes.
- Batch 2: Dry roast for 5 minutes.
- Batch 3: Dry roast for 10 minutes.
- Batch 4: Blanch in boiling water for 5 minutes.
- Batch 5: Blanch in boiling water with 0.25% baking soda for 5 minutes.
-
Soaking
Soak all five batches in water for six hours or overnight. -
Blending
Drain the beans and record their weights. Blend each batch with 500g of fresh water. -
Straining
Strain each blended batch to separate the milk from the okara. -
Cooking
Simmer the strained milk for 30 minutes to an hour.
Notes and Observations
Soaking and Pre-treatment Results
- 2-Minute Roast: Drained weight of 224g. The soaked beans had a soy-like aroma with a slight roastiness and reduced beaniness.
- 5-Minute Roast: Drained weight of 204g. The soaked beans tasted notably like peanut butter.
- 10-Minute Roast: Drained weight of 204g. The soaked beans tasted like dark, roasted peanut butter.
- Blanched (No Baking Soda): Drained weight of 224g.
- Blanched (With Baking Soda): Drained weight of 232g.
- Observation: Roasting time did not show a highly significant difference in water absorption, though the longer roasts absorbed slightly less water overall.
Yield and Texture
- During the straining process, longer roasting times correlated with a lower liquid yield and a higher volume of okara byproduct.
- All roasted batches except for the 2-minute roast failed to yield a proper milk. The proteins in the 5-minute and 10-minute batches likely pre-coagulated or denatured too much during roasting, resulting in a watery consistency.
- The 2-minute roast yielded a milk with a pleasant, somewhat neutral taste and a subtle roastiness, though some protein content still seemed to be lost.
Conclusions and Next Steps
- Pre-soak heat treatments (both roasting and blanching) appear to interfere significantly with protein yield in the final milk compared to post-soak treatments.
- For the next trial, it may be highly beneficial to reverse the order: start with a soak, followed by a brief roast, in order to maximally hydrate the proteins before cooking.