Straining and filtering home made liqueurs is a skill you will find that you will learn over time. The object is to do it as efficiently as possible to achieve the desired result. There is a really good article on filtration techniques at Gunther Anderson’s website here: http://www.guntheranderson.com/liqueurs/filters.htm. You’ll find that you’ll use coffee filters most of the time.
The kind of coffee filters I use are 8-12 cup basket filters along with a coffee maker funnel commonly found on many home coffee makers:
The filter funnel in this photo is made by Bunn-O-Matic, but similar ones are also made by Mr. Coffee, Proctor-Silex, Black & Decker, etc. But using coffee filters is the last step.
If there is a lot of fruit pulp or solids from nuts, seeds and herbs, then you will probably want to use an ordinary kitchen strainer first. I will generally use a regular stainless steel saucepan or pot with the strainer:
After straining you may want to use a metal coffee filter:
This is an insert that you put in the coffee filter funnel in place of a paper filter. I find that this will speed up the filtering process because it will trap a lot of pulp and small solids that would normally clog a paper filter. When the metal filter starts to get clogged, simply pour the remaining unfiltered liqueur back into the saucepan or pot then rinse it off in the sink, then continue filtering. It goes very fast.
If I am filtering fruit liqueurs, I will usually filter first using paper towels before using coffee filters. Then, as a final step I will use coffee filters. Going about it this way will generally make the process go smoothly.
Repeating a Step
If you find that any step goes slow or sluggish, you might want to repeat the same step. For example, when I strain and filter blackberry liqueur, I will usually use this routine:
- Once through a kitchen strainer
- Twice through a metal coffee filter
- Once though paper towels
- Twice through coffee filters
This will generally make the succeeding steps go faster and smoother. Overall the job will get done more efficiently and thoroughly.
No matter what, you will find that you will lose some of the liqueur through straining and filtering. For example, when making a batch of blackberry liqueur, the batch starts out at 5 cups, then it slowly gets whittled down to about 3 cups by the time I finished straining and filtering.
Clarification … Wait Before Bottling
When bottling the liqueur, I will want the purest, clearest liqueur possible … because I want the highest quality I can produce. Usually I will not bottle immediately, rather I will let the liqueur age and clarify for several weeks. When I am ready to bottle I will rack the liqueur. Racking is the process of letting all the sediments settle to the bottom and pouring or siphoning off the clarified liqueur off the top. I find that when making blackberry liqueur, that approximately the bottom 1/4 to 1/3 of the jar is too foggy to bottle.
Update: 27 Oct 2010
After a few years of experience, I found that it was easier and less time consuming to wait and allow the liqueur to settle and separate naturally as much as possible after straining with a stainless steel mesh strainer. One batch in particular really drove the point home for me. I had this batch of blackberry liqueur – and blackberry liqueur is particularly cloudy. I had combined all the cloudy parts after racking several jars into a single jar and let it sit for months. I was amazed that it settled and completely clarified without any further filtering all by itself. I racked off half the jar as perfectly clarified blackberry liqueur. I never thought I would be able to obtain that much good liqueur from such a mess of cloudy remains.
What I learned from this was to always wait for at least 30 – 60 days after doing one of the straining or filtering steps before doing the next step. For example, I will strain with a stainless steel mesh strainer, then wait 30 – 60 days, then filter with paper towels – or maybe not. Maybe I would be able to rack it off first, then filter with paper coffee filters. It all would depend on the kind of liqueur I was making and what it looked like. Always look to see how much the liqueur has clarified and settled by itself.
Generally, the thicker liqueurs or ones made with fruit will require more time and more filtering. Black currant liqueur made from dried fruit, for example, will usually have a lot of sedimentary material sticking to the sides of the jar and will require a lot of time to settle and a lot of filtering to clarify. But the more time you allow for settling and separating by itself, the easier it will be to clear up.
With a little patience you can save yourself a lot of time and a lot of paper coffee filters or paper towels – and save some liqueur that can be wasted in the process. Just let it settle out by itself as much as possible and let time do all the work.