So I prepared three otherwise identical batches of fresh chorizo with the following composition:
- 400 g pork shoulder
- 125 g pork backfat
- 9 g salt
- 12 g sweet pimentón
- 1 g hot pimentón
- 3,5 g fresh garlic (1 clove)
- 0,75 g dry oregano
- 25 g red wine
I cubed the shoulder and added just salt on batch 1, vacuum packed and refrigerated for 24 h.
On the second batch I added the salt and 3,2 g Supahos (diphosphates + emulsifier "mono- and diglycerides"), vacuum packed and refrigerated for 24 h.
The third batch was just cubed, vacuum packed and refrigerated. Salt and 1,25 g of Activa EB ("meat glue") were added before the mixing stage.
Then the frozen backfat and the meat were grinded through an 8 mm die, the spices added and everything mixed by hand keeping the mix temperature cold all the time. Mixing was intentionally not very strong.
After stuffing and linking the sausages were left 24 hours drying in the fridge, then cooked sous-vide for 1 hour at 60ºC.
Left to right: salt-only, Supaphos, and Activa
One day later, they were reheated and seared at the same time on a cast iron grill. The were tried by my wife (blind test) and me.
Left to right: salt-only, Supaphos, and Activa
The results confirmed the theory:
The salt only batch was ok but the mild mixing stage showed in a slightly crumbly texture.
Phospates helped to produce a sausage that was noticeable more moist and succulent and with a nice texture even though mixing was not deep. They also helped retain the red color during cooking.
Transglutaminase had a lower effect than expected. It was true that the sausage was firmer to touch after the 24 h drying stage and a bit harder on bite, but it was not so different from the salt-only one, and it lost more juices. Likely the lower juiciness was due to the later addition of salt with respect to the other two batches. I must also say that the Activa I was using maybe wasn't totally active. I opened the package about 6 months ago and rapidly vacuum-packed individual portions and froze it, but enzymes degrade fast even when properly stored as I did.
I don't have the measured weight losses now with me, but I will post them later.
Conclusion: Though extra binder agents are not really requiered in homemade sausages, the effects of phosphates are clear and produced a sausage we liked much more, so I'll use Supaphos regularly for fresh sausage. Activa is expensive and the effects are not so nice, so I will leave it only for "sausages" with special shapes (squares or sheets, as proposed by Modernist Cuisine) where its meat glue properties are really needed.
Edited: Changed back fat amount from 100g to 125g. Changed salt from 1,8g to 9g. Per EnriqueB.