What does gravity have to do with booze?

So, what does gravity have to do with booze anyway?  More specifically, what are original gravity and final gravity, and what do they mean?

Basically, these are measurements which relate to the sweetness, the dryness, and the alcohol content of a beer or wine.

Measuring actual sugar and alcohol content precisely and scientifically is a very complicated and expensive process.  By using gravity (more specifically, the original (OG) and final (FG) gravities) brewers and winemakers can estimate these measures.

Sugar is heavier than water, so by using a hydrometer, brewers and winemakers can estimate the sugar content of their juice or wort through the original gravity.  Water has a specific gravity of 1.000.  So, a hydrometer which rests slightly higher than it would in pure water (say, in juice or wort) would measure something like 1.050 or 1.060.  The higher the original gravity, the higher the sugar content of the juice or wort.

Alcohol, on the other hand, has a lower specific gravity than water.  As fermentation progresses, the specific gravity of the wort or juice drops as well.  Through their own and other brewers' and winemakers' past experiences, brewers and winemakers know what the expected final gravity for a given style of beer and wine is, based on the wort or juice, as well as the particular yeast strain.  During fermentation, they can use a hydrometer to check the "attenuation" or the degree of fermentation, of their product.  Each yeast strain, as well as grain or grape recipe, has a different expected or target attenuation.  That is, what percentage of the sugars will be turned into alcohol?

What does this mean for us as beer or wine drinkers?  Well, sweetness (as opposed to fruity flavors, which can come from esthers even in dry wine) is a measurement of the sugar remaining in a finished beer or wine.  Essentially, this is the result of two decisions the brewer or winemaker makes: how much sugar to start with (original gravity), and the degree to which the sugars will be converted into alcohol (attenuation), which affect the final gravity of a beer.

Final gravity is a direct correlation to sweetness, and is also a good measure of what the mouth feel of a beer will be like, more or less, since the heavier a beer, the heavier the body will be.

All other things being equal (original ingredients, or at least the original gravity of them), a higher alcohol beer or wine will be drier than a low alcohol beer or wine, as more sugar was converted to alcohol.  Meaning that if you want to make a sweeter beer or wine, there are three ways to do it.
1) You can add more sugar (malt/grain or grape juice) at the beginning of fermentation, or pull water out of your juice to concentrate sugars.  This will result in a higher OG, meaning more fermentable sugars.  Even after attaining the same degree of attenuation, this beer will have a higher final gravity, meaning both more sugar and more alcohol, than a beer with a more watered down, less sweet base.
2) You can stop fermentation, by either using a yeast strain with a lower alcohol threshold or lower expected attenuation, or by actually forcing fermentation to stop by removing yeast or changing the temperature or environment to stop fermentation.  This will create a lower alcohol, sweeter product.
3) You can add sugars during or after fermentation.  Depending on whether the goal is more alcohol and more sugar, or just a sweeter product, this can be done at various times during fermentation.  In winemaking, this is known as chapetalization, and is prohibited in certain regions and styles in old world winemaking.  If you add the same type of sugar (grape juice for wine, or malt/grain for beer), before fermentation is completed, you will wind up with a higher alcohol, sweeter product.  If you add the sugar after fermentation is completed, the ABV will remain steady, and the final gravity, or sweetness of the product, will increase.  Alternatively, you can add other types of sugar.  This is common in Belgian styles, where candy sugar, which is not fermentable by ale yeasts, is added to the wort to create a sweeter finished product, without limiting the fermentation of the sugars in the wort.

Craft Wine

I saw a post about this on Linkedin a while ago, and wanted to take a crack at answering the question.  Why is it that craft beer and craft spirits have been taking off growth wise, and craft wine does not seem to do the same?  Are there lessons to be learned from craft beer which could help wine do the same?

My basic answer is that, at least in my mind, craft wine does not exist as an actual product distinction from other wines, meaning any attempt at "craft wine" is more of a branding or business model than anything else.  I'll explain below some of the factors that make craft beer the amazing product it is, an then explain why I don't think wine has the same factor.

Craft breweries produce small batches of product. This is arguably the weakest of my points.  There are lots and lots of small batch wineries.  In fact, I would argue that there are so many small batch wineries that it is no longer a valid factor in determining what "craft" wine is.  There are a few large wineries, but by and large, almost all wineries are in the business of small batch production, and the idea of small batch wine production is nothing new.

Craft breweries are focused on quality.  Again, arguably, the problem is not that wineries aren't, but that wineries are.  Almost all wines on the market are produced with quality in mind.  And, in fact, unlike beer, in which quality has just become a factor for most consumers, cheap wine on grocery store shelves is a result of people becoming interested in fine wines, not the other way around.

Craft breweries focus on specialized and skilled techniques.  Wines have always done this.  Working with less ingredients, and less control over the condition of their ingredients, wineries have always sought to highlight, minimize, or eliminate flavors, or to achieve consistency through diverse vintages and growing conditions.  Even the mass produced wines require a lot of testing, tasting, blending, and skilled decisions to produce a consistent product year after year.  Unlike beer, where, given the same condition, one can buy ingredients which are identical and expect the same results, wine by nature is a fluid and inconsistent product.  So whether it is a particular nuance, or a consistent product, a winery seeks to make, there are always skilled techniques involved.

Craft breweries honor, respect, replicate, and expand on traditional brewing techniques, and create new styles.  Again, this is the story of most wines.  The wine making traditions have not changed dramatically due to industrialization.  There are more tools available, but the essential ingredients and processes have remained the same.  Also, the "traditional" wines never went out of style or became unknown to mainstream producers because cheap swill (read: Bud Light) flooded the market.  Traditional, high end wines, have always remained in the eye of the consumer, and been the standard other wines try to live up to.  In terms of innovation, every time a wine is made in a new location, or with a new type of grape for the area, it is innovative.  Much of the innovation comes long before the actual wine making process begins, and much of the skilled work involved in wine making comes from trying to achieve a desired result with a given product.

Craft breweries provide a variety of styles, not just a repetition on the same theme.  Again, wine has always done this, being made from several varieties, with each having dramatically different flavor profiles.  The terroir of the grapes, the maturation process (if any), etc. also provide a further level of differentiation.  Wine has never been a single-note product, and so making wine with a variety of flavor profiles is nothing new.

Craft breweries support local economies. There is a tendency for craft breweries to buy as local as possible, to have brewpubs which connect them to their community, and to truly incorporate their brands into their local environments, making it impossible to, say, pick up and move across the country (although it does happen).  More than a tendency, wineries have to be tied to their local environments.  Barley is malted, dried, and sold and shipped as a commodity.  Hops are turned into pellets and shipped around and across the globe.  Yeast can be put in a vial (or a bucket) and sent anywhere.  Grapes are heavy, messy, and perishable.  Meaning you can't really put them in a bag and mail them to Milwaukee or St. Louis.  Yes, grape juice can be shipped.  But it is expensive and messy, and changes the qualities of the product during transportation.  For this reason, wineries are inherently a local operation.  They have always bought local, because it is the only way to do business.  Their operations and tasting rooms have always boosted local economies, and most wine growing regions have huge industries built around wine tourism as such.  In traditional, old world, wine growing regions, the label on the wine actually labels the region, not the product.  That is how intertwined wine is with place.

The biggest reason craft wine will not take off is that wine has always been a craft industry.  Yes, beer started out that way, but for many years, the best known, most sought after beers by the general public, have been mass produced, cheap, light, crisp, drinkable, and very refreshing lagers.  Different brands have flooded the market with products that are all very similar.  The craft brewing industry thus came in and provided a contrast to what was on the mainstream market.

Wine, on the other hand, has always been a little snobbier.  The most sought after wines in the world have always been rare, bold, and highly individualized products.  Mass produced wine only exists because expensive, "classy" wine exists, and wine has always been associated with a certain, high end lifestyle.  The small batch industry is not fighting against the big guys for attention, reputation, or market share, as in craft beer.  Instead, the big guys are entering the world of what in beer would be called the "craft" producers.

That being said, I think that there are a few trends which fit the spirit of craft beer and spirit, and appeal to a similar market, but that I don't think differentiate a wine as a "craft" wine.  The first is experimental varietals, or experimental varietals for a particular region.  New York State wines fall into this group, and are becoming more popular, as do many wines from Santa Barbara County and other non-Napa and non-Sonoma AVAs in California.  While not necessarily more craft in a lot of ways, the wineries trying these out are bold and breaking from the mold of what wine, or American wine, is supposed to look like. 

The other area is sustainable wine making.  As wineries begin to be certified organic, sustainable, etc. there is a craft-like market developing specifically around sustainably-produced wines.