Making gin is easy, making good gin is a bit harder.
Making gin is pretty easy, perhaps that’s why so many distilleries do it, and perhaps why so many distilleries manage do it badly. Gin really requires only two things, a drinking quality alcohol, and juniper berries (or in the case of some gins juniper berry extract).
But that really is oversimplifying things. While technically juniper is the only defining characteristic of gin, the quality of both the base spirt, and the juniper berries matter. But gin made just like this wouldn’t be a very sophisticated drink. It would be boring, rather universal, and the only real differences might come from how many times the gin was distilled, and at what point the juniper was added to the distillation.
The thing that makes gin special is the third factor, one that doesn’t define gin, but is critical to making a good, or great gin - the secondary cast of flavoring that is the the botanical mixture. Botanicals are the herbs, spices, fruit, roots, barks and miscellany that give the gins their unique characters. A good botanical mix can elevate a gin and make it stand out, while a bad one can render a gin, even one made with high quality ingredients, into a low quality, less desirable product.
Almost all gins have the big three of botanicals mixed in, juniper, citrus, and coriander seeds in their base mixture.
And in truth you can make a pretty good gin at home. All you need to really do is chose a high quality base spirit add juniper and botanicals and give it some time. What you’d be producing is what technically is called compound gin (where the botanicals are added to an already finished base spirit), or bathtub gin.
Now the term bathtub gin, comes from prohibition here in the US. When the sale of booze was banned, spirits became a black market opportunity and all around the US people started turning base spirits into something more. Now this was during the heyday of gin, so everyone attempted to produce gin. And since the buying and transport of large containers like demijohns and carboys would have aroused suspicion, the iron bathtubs of the day often served as mixing vessels for raw spirits mixed with juniper and other flavorings. Understand this wasn’t distilling, as a large open vessel like a bathtub would not have worked for practical reasons but for mixing. And the mixing was done not just to make “gin” but to hide bad flavors and scents in the alcohols they were mixing it with. Many a toxic batch made with methanol was hidden this way.
Perhaps because of that after prohibition ended, gin no longer had that great desirable reputation as a high end spirit, but a low one, due to the bad gin that had been made during those years. it wasn’t just seen as low, but rather as a common man’s drink and thus a bit snubbed by the upper classes.
But I digress, the term bathtub gin is usually attached to bad gin (and erroneously to other bad homemade alcohols). A better gin made this way would be a compound gin. And while many aficionados might look down upon gins made this way, there are a few which are good to excellent that are made this way, some times all at once, or sometimes in separate distillations during the gin making process to produce gins with unique flavors and depth.
Making a gin greater than this requires more equipment, and frankly more skill It’s what the best gin makers really do and t’s where the artistry of a true gin maker begins to come into play. This level requires distilling your own spirits (at least one more time if you are starting with a base spirit instead of making your own) and distilling them again with added botanicals ( I’m not going to discuss the science of distilling here, there are plenty of good articles floating around the internet on that subject if you are interested).
Most good spirits, including gin are distilled multiple times, typically 3-7 times with each distillation making the spirit a bit smoother. And the artistry of creating a good gin, may involve adding different botanicals at different points in the distillation process. Or adding them all in one stage before distilling, and perhaps distilling again, and again, and again.
Of course distillers have one step more, (maybe two in the case of of some of the sweeter gins, or pink gins that add sweetener or bitters to the final product), they have to cut their gin with water to bring it to a drinkable level. How much it is cut would determine if it’s “Navy Strength” or regular gin.
Navy strength, gin isn’t just a marketing gimmick, the Royal Navy has a very specific reason for wanting Navy Strength gin - so long as the alcohol content was above 57.15% any gin that spilled (presumably in combat due to cannon shot) into the powder room, or onto gunpowder, would not prevent the gunpowder from sparking, so that guns could still be fired regardless of if the powder was a bit wet - anything lower than 57% and the water content would compromise the ability fo the powder to spark.
As to the taste this isn’t just a stronger, but a more intense one flavor wise, as less dilution of flavor has taken place. Some folks love it and some folks don’t, that’s a matter of personal taste. That said, all that extra alcohol can easily sneak up on you.
Irregardless of if navy strength gin is to your liking, it’s a gin, and all good good gins have to have a number of basic characteristics.
Juniper berries
a good quality pure (unflavored) base spirit (and it can be made from most anything)
A pleasing botanical mixture
You might also consider good water to be a key, and a lot of gin makers use special waters for their products.
As you might imagine, the devil is in the details, and the hardest part of the gin-makers art is number 3.. figuring out a pleasing botanical mixture and how to infuse it into the spirit. That takes a little magic, a little alchemy, science, luck and a good palate. That is the skill that allows gin-makers from all over the world to make so many different gins, with widely different flavor profiles.