If your distillation was careful and without mistakes, it's making the cuts that will determine whether you're making rotgut or fine spirits. This is the part where you decide which of the fractions you took from a spirit run you will save, blend and dilute to drinking or aging strength. The fractions you do not save for drinking may or may not be used in future distillations, but we'll keep them anyway, just in case.

As we discussed earlier making the cuts is based on the fact that the output of the still is constantly changing, both in alcohol content and in flavor. When you divided the still output into pints, you took the first step in making the cuts. The next step is to smell and taste each of those jars you collected, and choose those which taste good, or, for some, those which do not taste bad.

Foreshots

Basically, here's what you need to know to start making your keep/don't keep decisions: At the very start of a pot still run, the first distillate to come out has lots of harsh-tasting and bad-smelling compounds in it, compounds like acetone (fingernail polish remover), ethyl acetate, and acetaldehyde, along with some other nasties. Although this mixture is not toxic enough to make you sick, after you've smelled it, you just know you don't want any of this in your carefully-crafted spirit (or your mouth!), so you'll either throw this stuff away or use it for starting charcoal fires or removing magic marker stains. We call this fraction foreshots.

Heads

After the foreshots, the spirits start smelling much better, but there is still a harshness reminiscent of cheap whiskey. In fact, after your distilling experience, you'll be able to taste this fraction in commercial spirits, especially the cheap ones. Getting you to drink this stuff is how the distillers make money. Yes, the objectionable part of this fraction contains those same nasty compound as the foreshots, but due to the fact that potstill output is continually changing, it's far less objectionable. It will give you hangovers like much commercial spirits, something you'll experience much less with home-made spirits. This fraction is called heads.

Hearts

As the still run progresses and the distillate keeps changing, the compounds that had seemed so harsh in the foreshots and heads gradually decrease in concentration. If you've ever held a handful of fresh dark-roasted coffee beans to your nose and smelled that rich dark aroma, with just a trace of what makes skunks awful, you know that substances that can be repellent in strength, can also be delightful complexity in trace amounts. And that's exactly what happens to the still's output. Gradually that distillate becomes smooth and soft, and ghosts of delicate flavors caress your palate. When the distillate makes your eyes wide and your voice drop half an octave, the fraction is hearts, and this is what you want to save.

Tails

If you're lucky, the still will keep cranking out hearts for a long time, even though you may detect small changes in flavor, but the hearts will be smooth and lovely, for a while anyway. At some point, however, you'll detect a hint of something different happening. You may taste some nice flavors that you'd like to keep, but just a trace of something just a bit off will creep into your hearts. It won't be something harsh and sharp like the foreshots tastes, but rather a bit of mustiness, described by some (me included) as "wet cardboard". At the same time, if you are tasting directly at the still, you'll be aware that your distillate is losing its alcoholic burn, as in fact it now has less alcohol in it. What's coming out of your still now is tails.

Starting the Cuts in the Middle

Because it's easier to detect flaws in the distillate after you've been tasting good hearts, instead of the other way around, we start testing and tasting a fraction that was collected in the middle of the still run. This middle fraction will almost certainly be pure hearts. Let's say we have collected 15 pint vessels; we would then select pint #7 to test and taste first. Having tasted nice clean spirit, we'd then taste #6 and see if some flaws had crept into that fraction. Next test #8 for the same reason, and then continue on with #5,#9,#4,#10 and so on.

Diluting to a Standard %ABV (Alcohol by Volume)

Because the %ABV of the distillate gets lower as the still run progresses, #6 and #8 may both be good hearts, but #6 will have a higher %ABV than #8, and the apparent "heat" of the additional alcohol in #6 can confuse the comparison. For that reason, and the fact that the high %ABV of early fractions can stun our taste buds, we'll dilute a bit of every fraction to a standard %ABV before tasting; 35 %ABV (70 proof) is a good choice.

Since we can read both the beginning and ending %ABV from the collection jar label, a simple average gets us close enough to the actual %ABV of any collection jar. If we take a small sample of known volume, of a known %ABV from that collection jar, we can use the Booze Blender's Formula. If...

... then the Booze Blender's Formula is b=a(O-F)/F

For the sake of example, if I take 10 ml (milliliters, measured by a drugstore syringe) of distillate that is 54 %ABV, and I want to dilute that to a 35 %ABV sample, I would first subtract 35 from 54 and get 19, so (O-F)=(54-35)=19. I would them multiply that 19 by the 10 ml of original distillate volume, and get 190, so a(O-F)=10(54-35)=190. Finally, I'd then divide that 190 by the desired final %ABV (35) and get about 5.4 ml of water to add to that original 10 ml of 54 %ABV to get the desired 35 %ABV test strength.

Just to be safe, buy a gallon of distilled water at your grocery to do all diluting; tap water can often throw a test way off.

Because your sense of smell is so important in making the cuts, I used brandy snifters, or large-bowled wine glasses to test each sample. That way you can swirl the glass to see the "legs" of the liquor, and you can then get your nose in the bowl to take a big sniff, and finally a slurpy sip to get plenty of vapor over your tongue. You won't need or want much more than a teaspoonful or two of liquor in your glass, so dilute an amount of distillate appropriate to the number of tasters you have. After each sample tasting, rinse out your glass and your mouth with distilled water.

When you taste to make the cuts, record your finding and opinions on paper. The first time you do this you will not have some of the flavors in memory yet, but just write what you perceive.

Congratulations! You've just made the cuts on your first batch.