Hazel-nut Butter

Ingredients

Equipment Needed

• •Small rimmed baking tray
• •Clean kitchen towel
• •Medium mortar and pestle or compact food processor
• •Digital kitchen scale
• •4 to 5-inch (10 to 12 cm) fine-mesh sieve
• •Small lidded jar

Instructions

1. 1

   Warm, do not roast

   Heat the oven to 350°F (180°C). Spread the hazelnuts in one layer on a small tray and warm them for 6 to 8 minutes, shaking the tray once, until their skins look dry and begin to split but the nutmeats remain pale. The source's place at the front of the oven meant brief skin-loosening heat, not a deep roast; dark nuts would overwhelm the butter and change the intended flavour.

   Watch the nuts closely during the final two minutes. Their clean aroma should become noticeable, but they should not smell deeply toasted.
2. 2

   Slip the skins

   Tip the warm nuts into a clean kitchen towel, fold it over them, and rub firmly so the loosened skins flake away. Pick out the nuts and remove any large clinging patches, then let them cool completely. A few fine flecks will be caught by the sieve later. If the skins refuse to move, return the nuts to the oven for 2 minutes and rub again; forcing cold, stubborn skins off with a knife only wastes the nut.

3. 3

   Pound to a paste

   Put the cooled nuts in a mortar and crush them first to crumbs, then begin pounding them toward a paste. As the crumbs grow damp-looking, add the ice-cold water one or two drops at a time, pounding thoroughly after each addition. If using a compact food processor, pulse in short bursts and scrape the bowl often so the paste never grows warm. Stop when it is cohesive, very fine, and matte rather than oily. If a glossy ring of oil appears, stop and chill the paste for 10 minutes. Ça se rattrape: pound in another two drops of cold water until the oil draws back into the paste.

4. 4

   Work in the butter

   Add the softened butter to the hazelnut paste in four additions, pounding or processing each one fully before adding the next. The weights must be equal, because that balance gives enough hazelnut to flavour the sauce without making the butter grainy or heavy. Continue until the mixture is uniform and pale biscuit-gold. If it slumps or looks greasy, it has grown too warm; chill it for 5 minutes, then continue.

5. 5

   Pass through the sieve

   Set a fine-mesh sieve over a cool bowl and rub the mixture through with the back of a sturdy spoon, working in small portions. Scrape every ribbon of smooth beurre de noisettes from the underside of the sieve and discard only the coarse skin and nut residue left above. This replaces the original tammy, but not the act of sieving; that final refinement is what lets the butter disappear smoothly into Sauce Noisette. If the mixture is too firm to pass, leave it for 5 minutes at cool room temperature. Do not heat it.

6. 6

   Pack for service

   Scrape the beurre de noisettes into a small lidded jar, press parchment directly against its surface, and use it at once or refrigerate until needed. For Sauce Noisette, let the required portion lose its refrigerator chill before incorporating it so the butter disperses evenly. Add no salt or extra flavouring here; the finished sauce controls its own seasoning.

Chef Tips

• •Use raw hazelnuts. Fully roasted nuts have already released more of their oil, and their darker flavour pushes this delicate finishing butter away from the source formula.
• •A digital scale matters more than measuring cups here. Whatever quantity you make, weigh the prepared hazelnuts and use precisely the same weight of butter. C'est la même grammaire.
• •The water is measured only so you have enough beside you. Add it by drops and stop as soon as the paste stays matte and cohesive; a spoonful would make the finished butter wet.
• •Do not skip the sieve. The mortar builds the paste, while the sieve removes skin and coarse particles that would otherwise announce themselves in the finished sauce.

Advance Preparation

• •Make the finished beurre de noisettes up to 5 days ahead. Keep it tightly covered in the refrigerator, with parchment pressed against the surface so it does not absorb other aromas.
• •For longer keeping, freeze it in tablespoon portions for up to 2 months. Thaw the required amount in the refrigerator, then let it soften slightly and beat it smooth before using.

Frequently Asked Questions

Nutrition Information

1 serving (about 14g)