Centrifuged and Clarified Stocks: Restaurant Clarity

Ingredients

• For the base stock
• 2 L cold brown beef or chicken stock, fully defatted and cold
• For the clearmeat (raft method)
• 300 g lean ground beef or chicken, sinew removed
• 4 egg whites, lightly beaten, cold
• 150 g mirepoix, onion, carrot, celery, finely chopped
• 60 g tomato, roughly chopped; provides acidity to aid coagulation
• 1 small bunch mixed herbs, parsley stalks, thyme, bay leaf
• For gelatin filtration (modernist method)
• 2 L cold stock, same base as above
• 10 g leaf gelatin, bloomed in cold water, then dissolved into hot stock
• For centrifugation (modern restaurant method)
• 2 L stock, cold, defatted; run at 4,000 rpm for 20–30 minutes

Method

1. 1
   CLASSICAL RAFT METHOD — Step 1. Combine the cold stock with the clearmeat: ground meat, egg whites, mirepoix, chopped tomato, and herbs. Mix thoroughly while the stock is still cold. Transfer to a wide, heavy saucepan.
2. 2
   Step 2. Set the pan over medium heat and stir slowly and continuously from the bottom until the liquid reaches a bare simmer. As the temperature climbs, the egg proteins begin to denature and rise, binding particles as they go. Stop stirring the moment the raft begins to form at the surface — from this point the liquid below must not be disturbed. The raft is set when it holds its structure as a firm, unified mass across the surface: this is where the dish lives or dies. Any agitation after this point re-suspends particles and destroys the clarity irreversibly.
3. 3
   Step 3. Maintain the barest possible simmer — gentle bubbling visible at the edges only — for the duration of cooking, so the stock is drawn upward through the raft filter continuously. Ladle the consommé from below the raft through a fine cloth-lined strainer into a clean vessel. The finished consommé is crystal-clear and free of any suspended particles.
4. 4
   GELATIN FILTRATION METHOD — Step 1. Bloom the leaf gelatin in cold water, then dissolve it into the hot stock. Cool to room temperature, then freeze solid in a shallow container.
5. 5
   GELATIN FILTRATION METHOD — Step 2. Transfer the frozen block to a cloth-lined strainer set over a clean vessel. Allow to thaw slowly at refrigerator temperature. As the gelatin matrix melts, it releases clarified stock first; particles remain bound in the later-thawing gel. The stock is done when the drip runs clear and the gel above still holds its form.
6. 6
   CENTRIFUGATION METHOD — Place cold, defatted stock in the centrifuge vessel. Run at 4,000 rpm for 20–30 minutes. All suspended particles pellet to the bottom of the vessel. Decant the clear stock from above without disturbing the pellet. The result is ready when the decanted liquid is visually indistinguishable from water.