Frothing

Monday 13 May 2024

Noted:

• Prioritise the steamed milk texture (in order to produce latte art)
  • Milk with fat content greater than 3%
    • Silk Soymilk Fat Content per 240mL: ~4.5 g (~1.875%)
    • Kirkland Signature A2 Protein Organic Whole Milk Fat Content per 240 mL: ~9 g (~3.75%)
  • Efficacy of Soy Milk in producing latte art
    • Kept around 55°C, should be relatively easy with soy; higher temperatures may separate milk and foam
  • Which Non-Dairy milk froths best?
    • Oat milk is relatively dense, compares most to whole milk; highly tolerant of aeration
    • Soy milk relatively stable (high protein); quick to produce too much foam
    • Almond milk is watery; foam dissipates quickly
    • Coconut milk produces a nice gloss; quick to form large bubbles
  • How to froth Silk Soymilk
• Steaming & Foaming
  • Fat determines thickness and richness, protein stabilises, well-heated sugars increase immediate perception of sweetness
    • Fat
      • Lower fat content produces stiff, dry foam
      • Whole milk sets the usual standard: ~8 g fat, ~8 g protein per 240 mL
        • Kirkland Signature A2 Protein Organic Whole Milk per 240 mL: ~9 g fat, 8 g protein
        • Silk Original Unsweetened Soymilk per 240mL: ~4.5 g fat, 7 g protein
        • Silk Original Dairy Free Soy Creamer per 240 mL: ~24 g fat, 0 g protein
          • Silk Original Dairy Free Soy Creamer per 15 mL: ~1.5 g fat, 0 g protein
      • Barista Non-Dairy Milks
        • Oat-ly Oat Drink Barista Edition per 240 mL: ~7 g fat, 3 g protein
        • Chobani Oat Plain Barista Edition per 240 mL: ~8 g fat, 2 g protein
    • Sugar
      • Lactose is relatively heat-stable; will not degrade with steaming
      • Proteins in receptors are temperature-sensitive; temperature affects the immediacy of perceived sweetness
        • Ideal temperature for perceiving sweetness of dairy milk (lactose) as drunk: 57°C - 66°C
        • Ideal temperature for perceiving sweetness of soy milk (sucrose) as drunk: 37°C - 50°C
        • Ideal temperature for perceiving sweetness of oat milk (maltose) as drunk: unsure but should be closer to dairy than soy
      • Fat content seems to impact effect of temperature change on immediately perceived sweetness
        • High-fat: increased temp from 6°C increases immediate perception of sweetness
        • Low-fat: increased temp from 6°C has little effect on immediate perception of sweetness
  • Introduce air as heat is introduced, before it reaches room temperature
  • Agitate to homogenise mixture

To try:

• Mixture of Silk Original Unsweetened Soymilk and Silk Original Dairy Free Soy Creamer
  • 192 mL Silk Original Unsweetened Soymilk & 48 mL Silk Original Dairy Free Soy Creamer: ~8.4 g fat, 5.6 g protein
    • Four parts milk: one part creamer
  • 180 mL Silk Original Unsweetened Soymilk & 60 mL Silk Original Dairy Free Soy Creamer: ~9.375 g fat, 5.25 g protein
    • Three parts milk: one part creamer
• Oat-ly Oat Drink Barista Edition

On cleaning:

• Detergent base depends on present compounds
  • Dairy: organic and inorganic compounds
    • Alkaline detergents for fat and protein
    • Acidic detergents for minerals
  • Plant: organic (unless fortified)
    • Alkaline detergents for fat and protein
  • Equipment: Limescale and rust build-up from water and steam contact in milk circuit
• Recommended use: One acidic for every four alkaline