I've been making chicken liver mousse by frying some chicken livers. I cook some shallots, deglaze the pan with port, reduce it, and then combine all of the above with butter in the food processor and strain it. It seems like the results are kind of variable. I believe this has to do with the step of cooking the livers. Sometimes I get them more cooked, sometimes less. The product often has a kind of gritty texture that some of my family don't like.
In the recent posts on modernistcuisine they mentioned making chicken liver mouse by cooking the livers sous vide. In fact, the chef who did this specifically noted the problem of improper cooking of the livers. However, no information was given as to the temperature he used.
So I cooked the livers at 131 F for 2 hours and then followed the procedure above. The resulting product was extremely smooth. But it had an astringent aftertaste that ruined the mousse. In fact, I ended up throwing it away.
This brought to mind a different chicken liver preparation I had tried in the past where raw chicken livers were pureed with eggs and butter and the mixture was cooked sous vide. That product also had an astrigent taste.
So I'm wondering where this astringent taste is coming from and what is necessary to eliminate it. If I sous vide cook the livers at some higher temperature will I be able to get a result which is smooth, and has a flavor similar to the flavor I got when I pan fried the livers?