Foamability in barista plant‑based drinks

Understanding how protein–fat balance and calcium carbonate influence foam quality, stability, and performance in plant‑based milk alternatives.

Plant based drinks <p>Foamability in barista plant‑based drinks</p>

Why foam performance matters more than ever

Over the past five years, plant-based drinks have continued to consolidate their position in global dairy alternative markets, while innovation has shifted toward more function specific usage occasions, particularly coffee and barista applications. Product development has increasingly focused on foam formation, micro foam texture, and compatibility with espresso-based beverages, alongside broader trends toward nutritional fortification and cleaner label positioning1,2.

At the same time, the plant-based category faces an ongoing challenge around nutritional equivalence with dairy, particularly concerning calcium and micronutrients. As a result, fortification has become a standard formulation strategy across regions, with added calcium appearing in a significant share of new plant-based drink launches, especially in Europe and Asia1.

Within this context, barista‑style plant‑based drinks increasingly aim to combine reliable foaming performance with nutritional fortification, raising questions about how formulation variables, including minerals, interact with foamability.

How foamability in different barista grades was evaluated

To better understand the drivers of foamability in barista‑style drinks, a comparative evaluation was conducted on 11 commercially available plant‑based barista drinks, covering almond‑, oat‑, and soy‑based formulations. Cow milk (3.5% fat) was included as a reference.

The study focused on the relationship between foamability, foam stability, and formulation variables including protein content, fat content, fat‑to‑protein ratio, and the presence or absence of calcium carbonate and stabilizers.

All drinks were stored at room temperature prior to testing. A pre‑trial confirmed no significant difference between chilled and ambient conditions. Each drink was shaken for five seconds in line with on‑pack recommendations.

Foam was prepared by frothing 150 mL of each drink to 60-65°C using a standard milk frother.  Foam volume (overrun) and foam retention after five minutes were then measured using a graduated cylinder.

Overrun (%) = ((Vfoam - Vinitial) / Vinitial) × 100   Foam retained (%) = V(t) / Vfoam × 100

What the multivariate analysis reveals

Principal Component Analysis (PCA)

A principal component analysis was applied to explore relationships between samples and formulation parameters.

Article Foamability of barista‑style plant‑based drinks:

Figure 1. PCA score plot of milk alternatives including fat-to-protein ratio as an additional variable, with samples color coded by base ingredients (almond = orange, oat = blue, soy = green, cow milk = black); products containing calcium carbonate are highlighted with a red circle.

The principal component analysis highlighted two clearly differentiated dimensions: one primarily related to foam performance (PC1) and one related to formulation composition (PC2).

PC1: Foam performance and protein–fat balance

PC1 captured the main drivers of foamability across the evaluated samples:

  • PC1 was primarily driven by foamability, protein content, fat content, and the fat‑to‑protein ratio, separating products with strong foaming performance and higher protein levels from lower‑performing alternatives.

  • Cow milk and soy‑based drinks scored highest on PC1, indicating similar functional behavior, particularly with respect to foam formation and stability.

  • Almond‑ and oat‑based drinks generally occupied lower PC1 values, reflecting weaker foaming performance.

  • Within oat‑based drinks, some products shifted further away from cow milk as the fat‑to‑protein ratio increased, highlighting the negative impact of an imbalanced formulation on foam performance. 

PC2: Formulation choices independent of foaming

PC2 reflected differences in formulation composition rather than foam performance:

  • PC2 was dominated by formulation features, notably the presence or absence of calcium carbonate and stabilizers.

  • This axis distinguished products based on compositional choices, without a direct association to foamability or foam retention.

Overall interpretation

Taken together, the PCA indicates that foam performance is primarily governed by protein level and protein-fat balance (PC1), while calcium carbonate and stabilizers shape the formulation “fingerprint” of beverages (PC2) without directly determining foaming behavior. 

Variable Cluster Analysis

A variable cluster analysis provided further insight into how formulation parameters interact (Figure 2).

Foamability of barista‑style plant‑based drinks:

Figure 2. Clustered heatmap of variables × variables including fat-to-protein ratio, where colors represent the strength and direction of correlation (red = positive, blue = negative), and hierarchical clustering groups variables with similar functional behavior across samples.

Foam performance and its core drivers

  • Foamability and foam retention clustered closely, confirming that foam volume and foam stability co-vary and are closely linked functional properties.

  • Protein content clustered with foam performance variables, underscoring its central functional role and explaining the proximity of soy‑based drinks to cow milk in the multivariate space.

The role of fat and the fat‑to‑protein balance 

  • The fat‑to‑protein ratio clustered with foamability and foam retention, indicating that this balance is highly relevant for foam performance.

  • Fat content alone showed a weaker association, suggesting that fat contributes to foam properties primarily through its relationship with protein rather than through its absolute level.

Formulation components independent of foaming

  • Calcium carbonate and stabilizers formed a separate cluster, reflecting formulation choices that are largely independent of foaming behavior. 

  • Salt content showed weak correlations with other parameters within the tested range, indicating a limited influence on foam performance.

Overall interpretation

Overall, the cluster analysis reinforces that foam performance is primarily governed by protein and protein-fat balance, while minerals and stabilizers mainly characterize formulation profiles without acting as direct foam drivers.

What this means for barista‑style formulations

The combined multivariate analyses confirm observations widely reported in the scientific literature: foam formation and foam stability are primarily governed by protein level and protein functionality, rather than by minerals or stabilizers alone 3.

Soy-based drinks perform closer to cow milk largely because soy proteins possess interfacial properties that favor air incorporation and foam stabilization. Almond and oat-based drinks generally show lower foamability, although selected barista formulations demonstrate improved performance through optimized composition. However, it must be noted that the unique sensory profile of soy milk can restrict consumer acceptance3.

Fat content contributes to foam texture and mouthfeel but cannot compensate for insufficient or poorly functional protein. The fat-to-protein ratio clustering further shows that excessively high fat relative to protein is associated with weaker foam performance, particularly among oat-based drinks4. Within the tested range, salt played a negligible role in foaming behavior. 

Importantly, while calcium carbonate and stabilizers clearly distinguish formulations in a multivariate context, they do not appear to either enhance or impair foamability or foam retention under the conditions studied. This aligns with published work showing that insoluble mineral fortification, when properly dispersed, does not significantly interfere with protein-driven foam mechanisms.

Key takeaways for product developers

This study confirmed that:

Primary drivers of foam performance

  • Protein source and effective protein dosage are the primary levers for both foamability and foam stability in barista‑style plant‑based drinks.

The importance of protein–fat balance

  • Optimized fat‑to‑protein ratios must be considered for each plant base to avoid negatively impacting foaming performance, particularly in formulations with higher fat levels.

Ingredients that shape formulation, not foam

  • Stabilizers and calcium carbonate contribute to the overall formulation profile but do not act as direct drivers of foam performance.

Calcium fortification without functional trade‑offs

  • Calcium carbonate can be used for nutritional fortification without compromising barista foam quality.

These findings support formulation strategies that prioritize protein selection and inclusion range as well as fat-to-protein ratio, while using stabilizers to fine-tune sensory attributes. Calcium carbonate can be applied for nutritional fortification without introducing functional trade-offs in foaming, supporting the development of barista-style plant-based drinks that balance performance, nutrition, and label considerations.

Looking to optimize foam performance while integrating nutritional fortification in your barista‑style plant‑based drinks? 
Our experts support developers with formulation insights, ingredient selection, and application know‑how to help bring high‑performing barista solutions to market. Get in touch to explore how we can support your next formulation. 

References

1 Mintel Report (2025) A year of innovation in dairy & non-dairy drinks, 2025

2 Mintel Insight (2025) Anuga 2025, Cologne, October 2025

3 Gupta, A. et al. (2025) Barista‑quality plant‑based milk for coffee: A comprehensive review of sensory and physicochemical characteristics. Beverages, 11(1), 24. 

4 Ho, T. M., Xiong, X., Bhandari, B. R., & Bansal, N. (2024) Foaming properties and foam structure of milk determined by its protein content and protein-to-fat ratio. Journal of Food Science, 89(7), 2855–2868.

Curious to expand your knowledge?

Click here to read more and stay updated with the latest articles!

Explore now