Creating Perfect Pastes: From Pesto to Curry Paste

Pastes are the flavour foundations of cuisines around the world—from Italian pesto to Thai curry bases to Mexican moles. While modern food processors can create adequate versions, the mortar and pestle produces pastes with superior texture, depth, and aromatic intensity. The difference lies in how the ingredients are processed: bruising and grinding release oils differently than blade-cutting, creating a more cohesive and flavourful result.

Understanding Paste Construction

Every great paste follows a similar construction principle: build from hard to soft, dry to wet. This approach ensures even processing and proper emulsification.

The Universal Order

1. Hard aromatics: Dried spices, peppercorns, tough seeds
2. Fibrous aromatics: Garlic, ginger, lemongrass, galangal
3. Moist aromatics: Fresh chillies, shallots, fresh herbs
4. Tender elements: Soft herbs, citrus zest
5. Liquid components: Oils, fish sauce, citrus juice

This order prevents splashing, ensures hard ingredients don't damage tender ones before they're processed, and builds flavour layers systematically.

Italian Pesto: The Classic

True Genovese pesto made in a mortar bears little resemblance to the jarred versions most people know. The texture is silkier, the basil brighter, and the overall flavour more complex and rounded.

Traditional Genovese Pesto

Ingredients

• 2 cloves garlic
• Generous pinch coarse sea salt
• 30g pine nuts
• 60g fresh basil leaves (about 2 large bunches)
• 50g Parmigiano-Reggiano, finely grated
• 20g Pecorino Romano, finely grated
• 100-120ml extra virgin olive oil

Method

1. Add garlic and salt to mortar; grind to a smooth paste—the salt acts as an abrasive
2. Add pine nuts; pound and grind until you have a grainy paste
3. Add basil in three batches, pressing each addition against the mortar's sides with a twisting motion—work quickly to prevent oxidation
4. Once basil is incorporated, begin drizzling olive oil while continuing to grind
5. Transfer to a bowl; fold in grated cheeses
6. Adjust salt; add remaining oil to desired consistency

Common Pesto Mistakes

• Working too slowly—basil oxidises rapidly once bruised
• Adding cheese to the mortar—it becomes gummy; fold in at the end
• Using wet basil—excess water dilutes flavour and accelerates spoilage
• Over-grinding—pesto should have some texture, not be completely smooth

Thai Curry Pastes: Aromatic Complexity

Thai curry pastes showcase the mortar and pestle at its finest. The traditional pounding technique—using a large wooden or granite mortar with a heavy pestle—creates pastes with incredible depth impossible to achieve in a food processor.

Foundation Green Curry Paste (Prik Gaeng Khiao Wan)

Ingredients

• 1 tsp white peppercorns
• 1 tsp coriander seeds
• 1/2 tsp cumin seeds
• 8-10 green Thai chillies, chopped
• 4 tbsp chopped coriander roots (or stems if roots unavailable)
• 1 tbsp chopped galangal
• 2 stalks lemongrass (tender parts), sliced
• 1 tbsp chopped kaffir lime zest
• 8 cloves garlic
• 6 shallots, quartered
• 1 tsp shrimp paste
• 1 tsp salt

Method

1. Toast peppercorns, coriander, and cumin in dry pan until fragrant; let cool
2. Pound toasted spices to fine powder
3. Add salt; continue pounding to incorporate
4. Add coriander roots; pound until fibrous texture breaks down
5. Add galangal; pound until pulverised
6. Add lemongrass; pound until no fibrous pieces remain
7. Add chillies; pound until well integrated
8. Add garlic; pound to smooth paste
9. Add shallots; pound until paste is cohesive
10. Add kaffir lime zest and shrimp paste; final pounding to create unified paste

Red Curry Paste Variation

For red curry paste (Prik Gaeng Phet), substitute the green chillies with 10-15 dried red chillies (soaked in hot water for 20 minutes, then drained) and add 1 tablespoon of paprika for colour depth.

Mexican Salsas and Moles

The molcajete is central to Mexican cuisine, creating salsas with a rustic texture and depth that blenders simply cannot replicate.

Salsa Molcajeteada

Ingredients

• 4 Roma tomatoes, charred
• 2 serrano chillies, charred
• 1/4 white onion, charred
• 2 cloves garlic
• 1/2 tsp salt
• Handful fresh coriander

Method

1. Char tomatoes, chillies, and onion directly over gas flame or under broiler until blackened in spots
2. Grind garlic and salt in molcajete to paste
3. Add charred chillies; pound to rough paste
4. Add onion; pound until incorporated
5. Add tomatoes one at a time; pound to desired consistency (traditionally quite chunky)
6. Tear in coriander; pound briefly to release oils

Indian Masalas and Spice Pastes

Indian cuisine relies heavily on both dry spice blends (masalas) and wet pastes. The mortar excels at both.

Basic Ginger-Garlic Paste

This foundational paste appears in countless Indian dishes:

1. Equal parts fresh ginger and garlic (about 50g each)
2. Add 1/2 tsp salt
3. Pound until completely smooth
4. Add 1 tbsp neutral oil to help preserve

Store refrigerated for up to two weeks; freeze for longer storage.

South Indian Coconut Chutney Base

• 1 cup fresh grated coconut
• 2-3 green chillies
• Small piece ginger
• Salt to taste
• Handful coriander leaves

Grind chillies and ginger first, then add coconut in batches with a little water to achieve desired consistency.

Middle Eastern Pastes

Classic Harissa

This North African chilli paste demonstrates how soaked dried chillies create complex flavour:

1. Toast 1 tsp caraway, 1 tsp coriander seeds, 1/2 tsp cumin
2. Soak 6 dried guajillo or similar chillies in hot water 30 minutes; drain
3. Pound toasted spices with 1 tsp salt
4. Add 4 cloves garlic; pound smooth
5. Add rehydrated chillies; pound to paste
6. Add 2 tbsp tomato paste; incorporate
7. Drizzle olive oil while pounding to desired consistency

Troubleshooting Paste Problems

Paste Won't Come Together

• Add a pinch more salt—it helps release moisture and break down fibres
• Continue processing—some ingredients need extended pounding
• Add a small amount of liquid (oil or water, as appropriate)

Paste Too Watery

• Drain excess liquid from ingredients before adding
• Use less oil initially; add more at end if needed
• Process longer to evaporate excess moisture through friction heat

Uneven Texture

• Stop periodically and scrape paste from sides back to centre
• Ensure each ingredient is fully processed before adding the next
• Cut fibrous ingredients smaller before adding

Storage and Preservation

Homemade pastes have shorter shelf lives than commercial versions but offer superior flavour:

• Pesto: Cover with oil film; refrigerate up to 1 week or freeze in ice cube trays
• Curry pastes: Store in airtight container; refrigerate 2-3 weeks or freeze 3-6 months
• Salsas: Best fresh; refrigerate up to 5 days
• Oil-based pastes (harissa): Top with oil layer; refrigerate up to 1 month

Conclusion

Making pastes by hand connects you to culinary traditions spanning centuries and continents. While the process requires more time than machine processing, the superior results—both in flavour and texture—justify the effort. Start with simpler pastes like pesto or garlic-ginger paste, then progress to more complex preparations like Thai curries as your technique develops. Your cooking will be transformed by mastering this fundamental skill.