Batch #3 Split Test
This test is as scientific as I’m able to conduct at home. I used the exact same materials, time, lemons, etc. for both halves of one batch. The only difference was filtering the liquor. I wanted to see what kind of difference, if any, liquor filtration has on the final product. Here are the ingredients for the whole experiment.
Liquor: Two 750ml bottles of Everclear 151
Liquor filtration: Varies
Lemons: 17 Non-organic, waxed and scrubbed
Days peels and liquor rested: 55
Simple Syrup - Cups Sugar: 4, Cups Water: 5
Days syrup rested with infusion: 48
Final filtration: 4x
Just after zesting the lemons, I divided the zest into two even halves and put each half into an identical glass jar. I then poured one unfiltered bottle of grain alcohol in one jar and the other jar received an identical bottle of alcohol but after 4 filtrations in the Brita filtering pitcher. Everything else was identical down to the amount of time I waited to taste them and the temperature of the Limoncello at tasting.
The results for the first, unfiltered, half are:
As you can see, it’s fairly rough stuff. It’s pretty sweet, which offsets the harshness in the flavor somewhat but it has a lot of heat and is a very rough Limoncello. Drinkable but not great.
Here are the results of the second half of the batch:
As you can clearly see, the results were very different this time. The smoothness of this half of the batch was a world of difference from the unfiltered half. Compared to this half, the unfiltered half feels like getting punched in the throat. This one is smooth and silky with a little bit of heat and both halves had some off flavors on the finish that were probably due to the fact that I couldn’t use organic lemons and/or didn’t scrub them hard enough. Because of the smoothness, the sweetness of the Limoncello is more apparent which is why I rated this one as more sweet despite the fact that the two halves contain exactly the same amount of sugar.
With this direct comparison under my belt, I can tell you with absolutely no reservations that filtering the liquor makes a HUGE difference in the smoothness of the final product. Since this batch was created I’ve made a couple others and forgotten to filter the liquor. I’m now acutely regretting that. I strongly recommend that you filter the liquor before the infusion with the lemon zest. I plan future tests to see where the point of diminishing returns is on filtration. Less filtration is faster but if I could double the smoothness by filtering the liquor 8 times, I’d do it. It’s still much faster than letting the finished Limoncello rest for a year or two, which is what I’ll need to do with the unfiltered half.
20080223 2:20 pm
I use 100 proof vodka instead of everclear. do you think filtration is as important with vodka?
20080223 2:51 pm
I do filter my vodka as well. The filtration of the liquor is actually an idea I borrowed from other sites that filter cheap vodka to make it taste like high end vodka:
http://www.ehow.com/how_2041159_improve-vodka-filter.html
They even have contraptions to make multiple filtrations easier:
http://cocktails.about.com/od/spirits/gr/vodkastick_rvw.htm
I think how much benefit you get is closely associated with what kind of vodka you use. Using cheap vodka will definitely require filtration, but even then it will likely have off flavors. I use mid-grade vodka, usually 100 proof Smirnoff, and then filter it a minimum of 4 times. I think this is a good compromise of price and taste.
For making Limoncello, what you want is no flavor at all so the infusion can take on the flavor of lemon without other less desirable flavors. One other thing to know is that depending on your sugar/water mixture, Limoncellos made with 100 proof vodka can freeze in the freezer. This has happened to me a lot though I still use it because it’s very hard to get either Everclear or higher proof vodka around here.
20080529 1:59 pm
How long/how many times can you use a single Brita filter when you are doing your filtering? Is there any rule if thumb you use for when you toss the filter and get a new one?
Have you done testing yet to see if 4 filtering passes is that much better than 2?
Should you filter lower-proof alcohol more than higher proof stuff?
The filters aren’t that expensive, I suppose, but with the cost of the high-proof vodka it adds up.
(Great site, btw… I was just curious about making limoncello, but all the recipes i found seemed to just be posted by people who hadn’t actually tried them. I wasn’t going to bother, then last week I found your site. Last day of the 3-for-a-dollar lemons was today… zesting begins tonight!)
20080530 10:17 am
I’m not sure about how many times you can use a filter, quite a few but not as many times as with water. My rule of thumb for when to change it out is just to look at the flow coming out the bottom of the filter when you first pour the liquor in the top. When it reduces to drips I change out the filter.
I have done some batches with one or two filtrations and some with as many as six filtrations. I can tell you that one or two isn’t as good as 5 or 6, but that’s as fine grained as I can tell you right now. What I haven’t done but would like to do is filter like 10 times and see if that is a real improvement.
On the issue of proof, I usually do it by quality. I filter the lower quality, cheaper liquors more than more expensive ones. I think that generally speaking, filtering decent quality vodka doesn’t result in massive improvements (though still worth doing) but filtering grain alcohol is an absolute must and produces massive taste improvements.
I’m glad you like the site! Stop back and let me know how it goes for you!