• Almond flour is primarily produced via two methods: whole-kernel milling (blanched/unblanched) and defatted flour from screw-press extraction, with the latter achieving oil yields up to 52% and protein content around 55.9%, making it ideal for high-protein applications.
• Screw-press extraction results in lower fat content (~8.6%) compared to hydraulic pressing (~27.4%), which retains more oil but dilutes protein levels (~44.5%), impacting nutritional value.
• Whole-kernel blanched flour is preferred for premium gluten-free baking due to its fine texture and moisture retention, while defatted flour is suitable for protein fortification in various food products.
• The almond industry can enhance sustainability through valorization of by-products (skins, shells), aligning with circular economy principles and creating additional revenue streams.

Processing Routes & Yields

Product: Almond Flour
Section: Technology & Processing
Subsection: Processing Routes & Yields

Almond Flour Processing Routes & Yields: Industrial, Defatted, and Home-Scale Pathways

Executive summary

Almond flour reaches the market through two principal routes: (1) whole-kernel milling (blanched or unblanched) that retains the native oil, and (2) defatted flour recovered from the press cake after mechanical oil extraction. Peer‑reviewed evidence demonstrates that screw-press extraction at low rotational speed and moderate heat can achieve oil yields up to about 52% and produce a protein-dense, low‑fat defatted almond flour (~55.9% protein; ~8.6% fat). In contrast, hydraulic pressing tends to leave substantially more oil in the cake (flour fat 27.4%), diluting protein proportionally (44.5%) and increasing energy density. Both presses produce high-quality virgin almond oil with low free fatty acids and peroxides.

From an ingredient performance standpoint, screw‑press defatted flour is the most efficient pathway to a high‑protein almond ingredient; whole blanched milling remains best for fine, premium gluten‑free baking where fat aids tenderness and mouthfeel. Industrial pretreatments (dehulling, unshelling, blanching) and by‑product valorization (skins, shells, partially delipidified flour) are key to sustainability and functionality in the almond value chain (Influence of Pressure Extraction Systems on the Performance, Quality and Composition of Virgin Almond Oil and Defatted Flours, 2021; Almond By-Products: Valorization for Sustainability and Competitiveness of the Industry, 2021).

1) Taxonomy of “almond flour” by processing route

• Whole-kernel almond flour (unblanched): ground from raw kernels with skins; higher particle heterogeneity and visible brown flecks; retains native lipid fraction; typically used where rustic texture is acceptable. Industrial pretreatment includes dehulling and unshelling upstream; roasting or blanching may occur depending on product design (Almond By-Products review, 2021).
• Whole-kernel almond flour (blanched): skins removed (hot water/steam) before grinding to produce lighter color and smoother mouthfeel; widely used in premium gluten‑free baking; commercial processes may include electronic screening, steam pasteurization (as required), fine grinding, and sieving, with controlled storage to preserve quality (Treehouse California Almonds, 2023).
• Defatted almond flour (press-cake flour): produced by grinding the cake remaining after mechanical oil extraction. Composition depends strongly on press type and operating conditions. Resulting flours can be remarkably high in protein, with fat content reflecting extraction efficiency (Influence of Pressure Extraction Systems…, 2021).

2) Industrial pretreatments and by‑products

Almonds destined for ingredient manufacturing are dehulled and unshelled to isolate the edible kernel. Downstream, kernels may be roasted (skin retained) or blanched (skin removed), the latter generating peel and blanch water by‑products. Almond shells and skins are substantial coproduct streams and are increasingly valorized (e.g., energy via gasification, functional extracts), aligning with circular economy goals (Almond By-Products review, 2021). Partially delipidified almond flour (i.e., press-cake flour) already has commercial food uses (e.g., in “almendrados” biscuits), underscoring the ingredient value of these side streams (Almond By-Products review, 2021).

3) Defatted almond flour from oil pressing: routes, yields, and composition

Peer-reviewed work comparing hydraulic press (HP) versus screw press (SP) extraction provides the clearest quantitative basis to discuss yields and resulting flour composition.

3.1 Pressing parameters and oil yield

• Screw press (SP): Oil yield increases as screw speed decreases (more residence time) and increases with temperature up to about 100°C; above that, gains plateau. The highest oil yield reported was 52% at 150°C with 17 rpm, representing a slow, high‑friction extraction that maximizes expression of the lipid phase (Influence of Pressure Extraction Systems…, 2021).
• Hydraulic press (HP): Parameters include pressure (80–160 kg/cm²) and pressing time (2–4 min). While effective for obtaining virgin oil, HP left more oil in the cake overall (see composition below), implying lower de‑fatting of the resulting flour (Influence of Pressure Extraction Systems…, 2021).

3.2 Flour composition after pressing

The press cake was milled into flour, then characterized. The stark differences in extraction efficiency translate directly into flour composition:

Table 1. Proximate composition of defatted almond flour by press type (as reported)

Source: Foods (2021). Influence of Pressure Extraction Systems on the Performance, Quality and Composition of Virgin Almond Oil and Defatted Flours (Influence of Pressure Extraction Systems…, 2021).

Key takeaways:

• SP defatted flour is substantially lower in fat (8.6%) and higher in protein (55.9%) than HP flour, reflecting more efficient oil removal by the screw press.
• HP flour retains more oil (27.4%), yielding higher energy density (474 kcal/100 g vs. 380.5 kcal/100 g) and proportionally lower protein (44.5%) due to compositional normalization.
• Both flours are fiber-bearing (>3% crude fiber) and mineral-rich (ash ~6–7%), further supporting their roles as nutrient-dense ingredients (Influence of Pressure Extraction Systems…, 2021).

A separate study cited in the same source reported cold-pressed almond flour with ~8.8% oil, 49% protein, and 5.9% fiber, aligning broadly with the SP profile and reinforcing the use case for protein enrichment of foods (Influence of Pressure Extraction Systems…, 2021).

3.3 Oil quality and functional compounds

Despite the mechanical and thermal stresses of pressing, both HP and SP processes produced virgin almond oils with low free fatty acids and peroxides, suitable for direct consumption without refining. The extraction methods preserve fat‑soluble bioactives with antioxidant properties, enhancing nutritional value. The residual flours also contain minor compounds with antioxidant activity, supporting use as functional ingredients or natural antioxidants in fat‑containing products (Influence of Pressure Extraction Systems…, 2021).

3.4 Practical implications for yields

A useful way to frame yields is to consider mass balance at the unit operation level:

• Oil yield (SP) up to ~52% under optimized conditions (150°C, 17 rpm). The corresponding cake mass is the complement (e.g., ~48% of kernel mass before any moisture corrections), which is then milled into flour. The compositional profile of that flour (fat, protein, etc.) is as reported above (Influence of Pressure Extraction Systems…, 2021).

Note that the proximate percentages include categories that may be measured on differing bases (e.g., “total carbohydrates” vs. “available carbohydrates”), so direct summation to 100% should not be assumed; rather, the figures are best used for relative comparison of routes.

4) Whole-kernel almond flour: processing steps, yields, and attributes

Whole-kernel flours do not undergo oil extraction; the native lipid fraction remains in the flour, contributing to tenderness, moistness, and mouthfeel—desirable for premium gluten‑free baking. Industrially:

• Sorting/electronic screening removes foreign materials.
• Blanching (hot water/steam) removes skins for “blanched” flour; unblanched flours retain skins and have a speckled appearance.
• Grinding and sieving set the particle size distribution; superfine flours are prized for delicate crumb structures.
• Optional steam pasteurization reduces microbial load (customer‑driven).
• Storage in cool, dry conditions (e.g., ~45–55°F and ~65% RH cited by processors) mitigates rancidity risk and maintains quality (Treehouse California Almonds, 2023; Almond By-Products review, 2021).

Unlike defatted flour, yield for whole‑kernel milling is largely the kernel itself minus any removed skin. Because skins constitute a small fraction of kernel mass, the weight yield from kernels to flour is near one‑to‑one, with yield losses governed by sieving cuts (removal of coarse fractions) rather than oil removal.

5) Home‑scale milling: reported volumetric yields and cautions

Home grinding uses blenders, food processors, or coffee grinders. Reported “yields” are often given volumetrically and vary widely due to device, grind fineness, and sifting practice. Importantly, volume is not a reliable basis for yield because bulk density changes with particle size.

Examples from consumer‑oriented sources:

• 1 cup raw almonds yields about 1.5 cups superfine flour when sifting and regrinding coarse fractions (emphasizing the role of sifting in apparent volumetric yield) (Love & Olive Oil, 2024).
• 2 cups almonds to ~1 cup almond flour reported elsewhere, underscoring the volatility of volume-based claims (device- and method‑dependent) (A Clean Bake, n.d.).
• A culinary guide suggests about 3/4 cup almonds per cup of flour (again, a volumetric statement sensitive to grind and packing) (Swasti’s Recipes, n.d.).

Operational cautions:

• Over‑processing can heat nuts and express oil, leading to almond butter rather than flour; pulsed grinding and sifting loops mitigate this risk (Love & Olive Oil, 2024).
• For baking, blanched almonds generally produce a finer, lighter flour; unblanched yields a coarser, speckled product.

Because of the inconsistency of volume yields, weight‑based planning is recommended in product development and procurement contexts.

6) Route selection: yields versus functionality

The choice of pathway depends on target specification:

• Maximize protein content, reduce fat: Favor screw‑press extraction followed by cake milling. Under optimized SP conditions, expect a high‑protein (56%), low‑fat (8.6%) flour suitable for protein fortification and clean‑label enrichment in baked goods, pasta, and snacks. The trade‑off is reduced lubricity and tenderness relative to whole‑kernel flour, which may require adjustments to water, emulsification, or binding systems (Influence of Pressure Extraction Systems…, 2021).
• Maintain rich mouthfeel and premium crumb structure: Use blanched whole‑kernel flour. The native oil aids moisture and tenderness. This route is standard in gluten‑free baking applications emphasizing sensory quality. Yield is straightforward (near mass balance of kernels to flour) and process complexity centers on blanching and fine milling (Almond By-Products review, 2021; Treehouse California Almonds, 2023).
• Intermediate approaches: Although not quantified in the cited data, partial de‑fatting (achieved by tuning press conditions or blending whole and defatted flours) can balance functionality and nutrition—useful for applications needing some fat for texture but higher protein than whole‑kernel flour alone.

7) Operational levers and trade‑offs (defatted route)

• Screw speed (residence time): Lower rpm increases oil yield, producing leaner cakes/flours; higher rpm may leave more oil, improving palatability but diluting protein percentage (Influence of Pressure Extraction Systems…, 2021).
• Temperature: Gains in oil yield are evident up to ~100°C; above that, yield plateaus. Higher temperatures can increase throughput but warrant attention to thermal exposure of bioactives in both oil and cake (Influence of Pressure Extraction Systems…, 2021).
• Hydraulic pressure/time: Longer pressing and higher pressures improve oil expression but, in this study, did not match the de‑fatting level of SP at its best settings (Influence of Pressure Extraction Systems…, 2021).
• Quality assurance: Both HP and SP maintained oil quality (low FFAs, low peroxides), and the preservation of fat‑soluble antioxidants was reported—important for both oil and cake functional claims (Influence of Pressure Extraction Systems…, 2021).

8) Sustainability and valorization

The almond industry produces significant by‑product streams (shells, skins, blanch water, press cakes). Defatted flours epitomize high‑value valorization—concentrating plant protein, dietary fiber, minerals, and antioxidant capacity with demonstrated uses in foods and even as a substrate supplement in mushroom cultivation. These pathways reduce waste and improve the competitiveness of almond processing within a circular economy framework (Almond By-Products review, 2021; Influence of Pressure Extraction Systems…, 2021).

9) Opinion and recommendations

Based on the comparative, peer‑reviewed evidence, the screw‑press route—operated at low rotational speed and moderate heat—offers the most compelling balance of yield and ingredient functionality for defatted almond flour. It maximizes oil recovery (up to 52%) and produces a cake with an exceptional protein concentration (55.9%) and low residual fat (8.6%), enabling efficient protein fortification with clean labeling. Hydraulic pressing is entirely suitable for virgin oil quality but tends to produce a higher‑fat press cake (27.4% fat), which, while energy‑rich, dilutes protein proportion and narrows the nutritional advantage of the flour.

For gluten‑free bakery applications prioritizing fine texture, blanched whole‑kernel flour remains best-in-class. From a portfolio perspective, manufacturers can offer:

• Superfine blanched flour for premium crumb and tenderness (whole‑kernel route).
• High‑protein defatted flour (screw‑press route) for fortification and reduced‑fat formulations.
• Blends of whole and defatted flours to tune functionality and nutrition.

Strategically, investing in screw‑press capability and parameter control is justified where protein‑focused innovation is a priority. Concurrently, expanding valorization of skins and shells (e.g., extracts, energy) aligns with sustainability targets and can create additional revenue streams.

Appendix: Comparative snapshot of routes, yields, and attributes

Sources: Peer‑reviewed studies as cited above (Influence of Pressure Extraction Systems…, 2021; Almond By-Products review, 2021). Ancillary process details from industry communications are provided where relevant and noted as such (Treehouse California Almonds, 2023).

References

• Influence of Pressure Extraction Systems on the Performance, Quality and Composition of Virgin Almond Oil and Defatted Flours. (2021). Foods. https://pmc.ncbi.nlm.nih.gov/articles/PMC8151718/

• Almond By-Products: Valorization for Sustainability and Competitiveness of the Industry. (2021). Foods. https://pmc.ncbi.nlm.nih.gov/articles/PMC8394390/

• Treehouse California Almonds. (2023, November 1). Almond Flour Production and Storage Process. https://www.treehousealmonds.com/blog/almond-flour-production-and-storage-process/

• Love and Olive Oil. (2024, October). Homemade Almond Flour (Blanched & Superfine). https://www.loveandoliveoil.com/2024/10/homemade-almond-flour.html

• A Clean Bake. (n.d.). Almond Meal vs Almond Flour, Plus How To Make Almond Flour at Home. https://acleanbake.com/almond-meal-vs-almond-flour/

• Swasti’s Recipes. (n.d.). How to Make Almond Flour. https://www.indianhealthyrecipes.com/how-to-make-almond-flour/

Frequently Asked Questions

What are the main processing routes for almond flour?

Almond flour is primarily produced through two routes: whole-kernel milling (either blanched or unblanched) and defatted flour from press cake after mechanical oil extraction. Whole-kernel milling retains the native oil, while defatted flour can achieve up to 52% oil yield using screw-press extraction.

How does the protein content differ between processing methods?

Defatted almond flour produced via screw-press extraction has a protein content of approximately 55.9%, while flour from hydraulic pressing has a lower protein content of around 44.5%. This difference is due to the varying efficiency of oil extraction, which impacts the overall composition of the flour.

What are the yields associated with screw-press and hydraulic-press methods?

Screw-press extraction can yield up to 52% oil, with the remaining cake milled into flour that contains about 8.6% fat. In contrast, hydraulic pressing typically leaves more oil in the cake, resulting in a flour with around 27.4% fat and higher energy density at 474 kcal per 100 g.

What are the implications of using blanched versus unblanched almond flour?

Blanched almond flour is preferred for premium gluten-free baking due to its lighter color and smoother texture, while unblanched flour retains skins, resulting in a coarser product with visible flecks. The choice affects the sensory quality and mouthfeel of baked goods.

How do industrial pretreatments affect almond flour production?

Industrial pretreatments like dehulling, unshelling, and blanching are crucial for isolating the edible kernel and enhancing the quality of almond flour. These processes also generate by-products, such as almond skins and shells, which can be valorized for sustainability.

What are the nutritional benefits of defatted almond flour?

Defatted almond flour is high in protein (up to 55.9%) and low in fat (around 8.6%), making it an excellent ingredient for protein fortification in various food products. It also retains dietary fiber and minerals, contributing to its nutritional value.

How can businesses decide between different almond flour processing routes?

The choice of processing route should align with product goals: for high protein and low fat, opt for screw-press extraction; for a premium texture, choose blanched whole-kernel flour. Blending both types can also balance functionality and nutrition for specific applications.