Sauce not thickening

OK - I am making a vodka, cream and green peppercorn sauce for a dinner tomorrow night. I've made it before but this time it is not thickening as it should. The only change is I doubled the recipe.
All that's in it is:

2 sticks of butter
1 cup of vodka
3 cups of whipping cream
4 tbsp crushed green peppercorns
6 tbsp lime juice
salt and pepper

Melt one stick butter. Add vodka and cream and boil until slightly thickened.
Add the other stick of butter and when it's just melted, add peppercorns.
Add lime juice, salt and pepper to taste.

When made last time, sauce was nicely thickened but this time it's just about as thick as the whipping cream.
Any suggestions? Any shortcuts to get it to thicken?

OK - I am making a vodka, cream and green peppercorn sauce for a dinner tomorrow night. I've made it before but this time it is not thickening as it should. The only change is I doubled the recipe.
All that's in it is:

2 sticks of butter
1 cup of vodka
3 cups of whipping cream
4 tbsp crushed green peppercorns
6 tbsp lime juice
salt and pepper

Melt one stick butter. Add vodka and cream and boil until slightly thickened.
Add the other stick of butter and when it's just melted, add peppercorns.
Add lime juice, salt and pepper to taste.

When made last time, sauce was nicely thickened but this time it's just about as thick as the whipping cream.
Any suggestions? Any shortcuts to get it to thicken?

Just sorta thinking out loud Jon, but I wonder if one could dissolve a little (TB) of corn starch in a 1/4 cup warm water and use that to thicken the sauce?

You mean, last time it was 1 stick of butter, half a cup of vodka, etc?

Is the sauce deeper in the pan this time than it was last time? I've found that a thin layer of a sauce like that thickens more easily than a deep pot of it.
Are you cutting up the second addition of butter and stirring it in as it melts? I have an unsubstantiated belief that the finishing butter, like beurre blanc, should be fed in a bit at a time, not all at once.

Bob's suggestion of a bit of cornstarch and water would serve for a rescue operation.

John

John's right: the likely culprit is that you didn't evaporate as much water out of it this time because you changed the surface-to-volume ratio. Given the ingredients, you could probably thicken it by binding it with a bit of flour. Arrowroot or cornstarch would work, too. In each case, the flavor will change subtly,though. My recollection is that arrowroot actually imparts less flavor than the other options.

Mark Lipton

[Jenise]

Jon, looking at the ingredients, the vodka's going to thin the cream, and the steps of rapid evaporation through boiling and adding the second butter stick (this is why it's added at the end) will both thicken and create a luxurious texture. However there are right ways to do both, and if your method deviates or you use a different cream this time than last, you would see some difference in your results. So if as Mark supposes your cream-voda mixture didn't cook down as much as before, and if as John supposes your butter was added to too hot a base mixture and liquified completely, you could have subverted the process. Optimumly, your second butter stick is added very cold in cut up pieces to allow it to bind with the sauce at a very low temperature, in effect thickening the sauce where, completely melted, it would thin it.

Like the guys, I would consider using a slurry to thicken the sauce slightly, but I'd be tempted to attempt further reduction first. Also, even before that just lightly reheat it--you might find the texture more agreeable after it cooled and chilled overnight.

Anyway, interesting sauce. What are you serving it on/with?

I took off from work a little early and came home and made the sauce again, taking suggestions posted here (sliced butter for second addition, different pan, etc.) and things have turned out very nice. Thank you Bob, John, Mark and Jenise - you are such a wonderful resource!
Jenise - I am serving this with grilled salmon and a dry white, maybe Prosecco.

I am serving this with grilled salmon and a dry white, maybe Prosecco.

Oh yum! What time is dinner?

I'm happy for you that it worked out this time.

John