Silken Tofu Experiments
Background
The goal of these trials is to experiment with different variables for making set tofu. The primary areas of focus are:
- soy milk thickness (ratios of soaked beans to water).
- Steaming methods (using a combi oven, comparing covered vs. uncovered).
- Inclusions (oil, blended vegetables, salt, and sugar).
- Coagulant types (Gypsum, GDL, and Nigari).
- Mixing techniques (blending the coagulant vs. gentle stirring) and steaming times.
Notes and Observations
Trial 1: Soy Milk Ratios & Pre-Blanching
This initial test compared unblanched soy milk at various concentrations against a blanched soy milk version (intended to yield a more neutral flavor).
Setup:
- Base: 240 g soy milk per batch, with a small amount of baking soda added at the beginning (as detailed in the basic soy milk recipe).
- Coagulant: 1 g gypsum dissolved first in a small portion of the soy milk, then whisked back into the main volume until fully dissolved.
- Cooking: Steamed in a combi oven starting with a 12-minute steam time.
Results by Ratio (Soaked Beans to Water):
- 1:3 Ratio (Unblanched): Set okay, but the texture was relatively light.
- 1:2 Ratio (Unblanched): Set with a very nice, soft firmness. There was some bubbling on the surface and slight porosity on the bottom. This is the most promising baseline, though it needs to be creamier, smoother, and free of bubbles.
- 1:1.5 Ratio (Unblanched): Not significantly thicker than the 1:2 batch, but developed a slightly grainy texture. The high density of the milk may have caused the proteins to pre-coagulate during heating.
- Pre-Blanched Version: Yielded a lower protein extraction through the cheesecloth, likely because some protein coagulation occurred early during the blanching step.
Trial 2: Inclusions (1:2 Baseline)
Using the successful 1:2 ratio as a baseline, this trial tested the effects of salt, sweetener, and oil inclusions on the set and texture of the tofu.
Setup:
- Base: 240 g of 1:2 soy milk.
- Coagulant: 1 g gypsum.
- Technique: Minimal mixing to avoid introducing air bubbles.
Results:
- Salt Inclusion (1.5 g salt): Resulted in a weaker gel structure and poor water retention (noticeable syneresis/wheying out).
- Sweetener Inclusion (8 g honey): Set successfully, but the resulting texture was quite soft.
- Oil Inclusion (5 g oil): Noticeably creamier texture. It set well, though it was slightly less firm than the plain 1:2 baseline.
Method
This refined method produces a smooth, bubble-free set across various milk thicknesses:
- Prepare Coagulant: Mix equal parts gypsum and GDL. Bloom the mixture in a small amount of water for 10 minutes.
- Combine: Gently stir the bloomed coagulant into the soy milk container using a spoon to avoid incorporating air.
- De-bubble: If any bubbles form on the surface, pass a blowtorch quickly over the top to pop them before cooking.
- Steam: Steam until set.
Note on Thickness: An immersion-blended 1:2.5 soy milk yields a very soft, delicate texture similar to ginger-set soymilk. A Vitamix-blended 1:2 soy milk will yield a much firmer set, which can be adjusted to taste.