Milk Punch Filtration Using A Vacuum Filter

I've been into milk punches for quite some time now, but I've struggled to find a clear, concise, quick and easy way to accomplish the most important part of the process: the actual filtration of the milk curds and solids from the solution.  Until now...

If you're not familiar with milk punch, and I'm specifically referring to the classic punch like the one laid out in Dave Wondrich's book, "Punch: The Delights (and Dangers) of the Flowing Bowl", then you should definitely find some time to get up to speed.  The basic principle behind it is using milk to remove the color from a darker spirit like a brandy or whiskey, while at the same time creating a liquid that has a rich and silky mouth feel, and can last a significant amount of time refrigerated once bottled.

My current recipe is as follows and produces around 2,250 ml (3 wine bottles) of milk punch:

• 32 oz Bourbon infused with peel from 1 orange
• House-made Chai masala (star anise, fennel seeds, saffron, vanilla bean, cinnamon, etc.)
• 1/2 lb Sugar
• 32 oz Water
• 16 oz Milk (organic whole)
• 3 oz Lemon juice (2 lemons freshly squeezed)

Using the peel of one whole navel orange, I allow it to infuse with bourbon for 24 hrs in a large jar.  At the same time I combine the sugar, water and Chai masala and allow it to steep for 24 hrs in a large jar.

After 24 hrs have gone by I combine the two jars.  I then slightly bring to a boil the organic whole milk and pour into the jar containing the other ingredients.  Then I add the lemon juice to the mixture to "break" the milk, and shake and let sit for an hour.  The citric acid in the lemon juice is what drives the separation of the milk into its clear and not clear parts.  During this time you'll see the mixture separate (the clear liquid with have a yellowish tint).

Once the mixture has cooled it's time to filter the clear deliciousness from the murky other stuff.  Every source I've come across has recommended using a cheese cloth or some other fabric to filter out the curds.  And this is fine if you have hours of time to dedicate to the process, because it will in fact take numerous rounds of filtering to reach the desired result - a crystal clear punch that looks delicious.

The Solution
Use a mother-loving Buchner funnel!!

If you don't know what a Buchner funnel is, just think back to your high school, maybe even middle school chemistry class days (or Google it).  The Buchner funnel is sealed to a flask using a rubber gasket which forms an air tight seal.  A tube is then connected to the flask and attached to either a pump or a faucet to create a vacuum in the flask.  Filter paper is placed in the funnel and once the liquid is poured into the funnel the vacuum pressure sucks the liquid through the paper and leaves behind the solid particles which are too large to pass through.  And it does so much faster than the typical cheese cloth filtration.
One quick tip, be sure to wet the filter paper with whatever your base liquor is, prior to adding your mixture (i.e. bourbon if your punch is made with bourbon, cognac if your punch is made with cognac).  After the filter paper is saturated and the pump has been pumped several times this will create the vacuum seal on the paper that will prevent any unwanted stuff from passing through the sides of the paper.  You might have to press down on the paper a little while pumping to make sure it's perfectly flat on the funnel.

My setup is:

• 12.5 cm (diameter) ceramic Buchner funnel
• 2,000 ml flask with spout
• Hand pump
• Plastic tubing
• Rubber gasket to form a seal between the funnel and the flask
• Medium 12.5 cm filter paper

All of which I acquired at http://www.sciencecompany.com/ for around $100.

Here's a pic of my setup.  The jar in the foreground is 1 liter and the one in the background is 3 liters.  I also had another 1L in the fridge.

And here's a pic of the final product in the 3 liter jar.

As you can see, the milk punch passed through the filter crystal clear... after only with 1 attempt.  In total I'd say it took about 2 hours to do the entire batch of milk punch, as this was also my first time attempting this method.  I was slow and cautious.  Didn't want to screw anything up or break anything.  In the future I'd imagine the process will go much faster.  

Cheers!