Prohibition, Temperance, and Pseudoscience

This post deviates a from my normal blog topic (making alcoholic beverages). Why is prohibition important? Well, Alberta still has legislative and regulatory "quirks" that are holdovers from the days of prohibition in Alberta. For example, in home winemaking, there is no legal way for a wine kit supply store in Alberta to provide customers with a clean, physical space inside the store in which to make wine, store it as it ferments, and bottle the wine when it's ready. These services are popular in other provinces, but are not allowed in Alberta, because such a service goes beyond "home winemaking". Governments in Alberta are liberalizing the liquor laws, but there is a long way to go. An interesting documentary account of the history of beer in Alberta, including the impact of prohibition, can be found at: Aleberta

Some time ago, I was surfing through the photo collection of the Provincial Archives of Alberta, and came across a bunch of old "Temperance posters". These posters were published by "The Dominion Scientific Temperance Committee", which, I gather, was an arm of the Women's Christian Temperance Union back in the days of prohibition. Some of these posters are quite amusing:

Provincial Archives of Alberta, Object number PR1974.0001.0400a.0001

Provincial Archives of Alberta, Object number PR1974.0001.0400a.0006

It is not clear to me what phagocytosis (the white blood cell "swallowing and digesting" germs) has  to do with alcohol consumption. Clearly, the idea was to scare people away from consuming alcohol, and, I suppose, get them to drink water instead.

The next poster piqued my interest because it touches on some chemistry.

Provincial Archives of Alberta, Object number PR1974.0001.0400a.0002

The poster argues that the nutritional value of grape juice is much greater than that of wine, but the numbers don't make a lot of sense. The only number that looks correct is the 20% "food value" of grape juice. That number roughly corresponds to the percentage (by mass) of sugar in grape juice. However, the percentages of water, alcohol, and "food value" in wine do not make sense.

1) The water content of wine is a lot higher than 78%. Water is a by-product of the fermentation of sugar. So, during fermentation, sugar decreases, and the proportion of water and alcohol increase.

2) The poster gives 17.5% alcohol for wine. Is this 17.5% by mass or 17.5% by volume? On wine, beer, and liquor labels, alcohol content is usually listed as a percent by volume. 17.5% would be on the high end of percent volume for wine. This poster, however, seems to be using mass percentages. The mass percentage should be a lot lower, because the density of pure ethanol is less than that of water. So, there is something funny going on.

3) The food value of wine is listed as 4.5%. Sure, wine contains residual sugars and other organic components that have nutritional value, but this number appears to have simply come from subtraction: 100 - (78 + 17.5) = 4.5. But, as the percentages of water and alcohol are suspect, so is the 4.5% value.

4) The poster implies that alcohol has zero food value, which is incorrect! The caloric content of foods and beverages can be determined through calorimetry: In the good old days, a scientist would combust a sample of food in a sealed chamber and measure the amount of heat produced. Calorimetry is a lot of work, so nowadays, the caloric content of foods is determined indirectly using the "Atwater system" (Scientific American has an article on this, here). Basically, this involves adding up reference caloric values for different components of the food or beverage in question. The reference caloric value of carbohydrates (including sugar) is 4 kcal/g (1 kcal = 1 food Calorie). The reference value for alcohol is... wait for it... 7 kcal/g! (Yes, on the basis of mass, alcohol has more food Calories than sugar.) So, the poster is WRONG.

The web site Compound Interest has a lot of neat infographics about various familiar substances. Take a look at their infographic on red wine. Their numbers make a lot more sense (86% water, 12% alcohol, 2% other organic compounds).

By the way, the "food value" of a 5 oz. glass wine is around 125 Calories, which is equivalent to 25 jelly beans. The glass of wine is arguably the healthier option of the two!

These temperance posters were published ca. 1912. Are these scientific mistakes forgivable, given that they were made over 100 years ago? Not really. Even in 1912, physics and chemistry were sufficiently advanced that mass and volume compositions were well understood and measured reliably. And, calorimetry was already an established experimental technique in the field of thermodynamics, which had its heyday in the age of steam engines. What's going on here is the twisting of information to support a particular agenda. It's pseudoscience!

Valpolicella Racking, Stabilizing, and Degassing

Today, I racked, stabilized, and degassed the Valpolicella wine.  The kit instructions are to do this at day 14, but this is day 19.  I let the wine sit an extra five days because the fermentation was not quite complete at day 14.


After the usual sterilization of equipment, I transferred the wine to a clean carboy via autosiphon, without incident.  During this 'racking' step, I took a sample for a tasting.  Well, well, this is nice stuff.  This wine is dry and gentle.  There are woody and nutty tones with a hint of almond.  The tannins are noticeable at the end.  I have hopes for a very nice table wine that will pair well with pasta dishes.

Tasting.  Note-taking is important when it comes to stuff like this.

The specific gravity was 0.990.  From the starting point, this gives approximately 16% alcohol.  Yes, it's pretty dry.


The next step is the addition of potassium metabisulfite, which is provided with the kit.  Out of curiosity, I used my little portable balance to measure the mass of K₂S₂O₅.  The mass of K₂S₂O₅ was 4.4 g.  For comparison, I weighed a Campden tablet.  It was 0.6 g.  The recommended use of Campden tablets is 1 tablet per gallon of wine.  This is a 23 L kit, which is about 6 gallons.  6 gallons x 0.6 g per gallon = 3.6 g worth of Campden tablets.  So, this amount isn't too far off.

When you add the K₂S₂O₅ to the wine, SO₂ gas is formed (see picture).    The chemistry of this step is quite straightforward, and one of these days I'm going to write a blog post about it.

SO₂ bubbles.  You can get rid of the excess gas by stirring vigorously.

After the K₂S₂O₅, I added potassium sorbate and then a small packet of kieselsohl.  Tomorrow, I complete the addition of clarification agents, and then I wait three weeks until bottling.

Rhubarb Wine: Interim Satisfaction

Twelve days ago, I started the rhubarb wine.  I've been out of town for half of that time.  Today, I got around to checking on the progress.  When I opened the lid on the plastic bucket and looked at the surface, I could tell that fermentation was on the tail end.  There just wasn't a lot of "activity" in terms of bubbles.  I quickly sterilized a 3 gallon carboy and my auto-siphon and got to work racking the wine into a carboy.

Some observations:

1. Specific gravity = 1.012.  The initial s.g. was 1.097.  Therefore, the approximate alcohol content at this point is somewhere between 13.0 and 13.5 %.  (It's getting close to being done!)
2. The colour!  There is a nice peachy pink colour now.  I thought the colour had been totally  bleached by the campden tablets, but there might be something else going on.
3. The taste!  (Naturally, I tested it!)  There was no tartness at all, just a mild rhubarb flavour, along with a gentle grape taste from the concentrate that I added.  This has the potential to be a very nice dessert wine.

Front: Rhubarb wine, with some colour.  

Back: Mead, just prior to adding kieselsohl.

Mead v.1 has been sitting in a carboy for about 12 days as well, and there was a nice build up of lees at the bottom.  I racked it into another carboy and then added the kieselsol, which is step 1 of the finings.  And, I sampled the mead too.  It's getting better!  The taste has mellowed out a little and I think it will be really nice when it is chilled.

Mead at 6 weeks

For the last two weeks, the fermentation rate has been falling slowly.  Two days ago, I made the decision to stop the fermentation.  There was a nice layer of lees at the bottom of the carboy.  The bubble rate was down to 2 per minute.  I reckon that the fermentation probably would have continued for a week longer.  It was the specific gravity that tilted the decision to stop.  The initial specific gravity was 1.120, and it had fallen to 1.019.  Yes, with that final specific gravity, there is probably a small amount of fermentable sugars remaining.  However, from the hydrometer scale, the difference between starting and final specific gravities corresponds to an alcohol content of approximately 15%.  I felt that this was more than strong enough.  If there's a little sugar left, so be it.  It will taste sweeter.

So, I siphoned the mead into a sterilized secondary fermenter, and then added 1 tsp. of potassium metabisulfite and 3/4 tsp. of potassium sorbate, with lots of stirring in between.  Two days later, I haven't noticed any activity, and there is a nice layer of lees that has already settled out.

(1) Mead immediately after racking to the secondary.

After racking the mead, there was a small volume remaining in the primary and in the siphon hose.  So, I sampled it.  It was better than the junk I was served at that barbecue many years ago.  However, the unprocessed mead I tasted had some carbon dioxide in it, which made the taste sharp.  That will hopefully disappear with time.

 (2) Sediment two days after racking.

My plan is to let this sit for the next week or so, and then add the finings to make this beverage crystal clear, and ready for bottling!