OT: Question on Calories

[Bartman]

Beersmith calculates my latest IPA @ 317 calories per pint. What has more calories, the sweet unfermented wort or the beer with alcohol?
Just curious!!!

 

[LumberJack]

Most definately the unfermented wort. I had once figured the conversion, put it into a spreadsheet and then forgot it. The fundamental is that things tend to progress to less energy (less calories) and I believe the sugar has 9 calories per gram and the alcohol about 5. In any event the higher the OG the higher the calories and the lower the FG, the lower the calories (all other things being equal). If you want I can send you my spread sheet - it calculates almost everything of interest.

 

[Rick500]

Wow, that's gonna be a big beer.

 

[Bartman]

Thanks LumberJack. I kinda figured the yeast would be unable to produce additional calories. First post???

 

[david_42]

Sugars run 4 Kcal/gram and alcohol 5 Kcal/gram. About half the fermentable sugar becomes alcohol.

 

[RogerMcAllen]

Fat is 9 Cal/gram
Carbs and protien are 4 Cal/gram
Alcohol is 7 Cal/gram

The wort definitely has more calories though. The yeast use a lot of them to make the EtOH, CO2, grow, etc.

 

[Killer_Robot]

The process of turning fermentation only uses some 6% of the potential energy in sugar, so the calorie difference between the wort and the final beer is pretty small. On the other hand, alcohol has a much higher calorie density than sugar because while the fermentation released little energy, the CO2 produced is nearly half the weight of the original sugar - several pounds of CO2 go out the airlock when making a big beer. This means that the alcohol left behind is a much more energy-dense material: it also means that beer is markedly lighter than the original wort, which is how it loses SG while not expanding appreciably.

 

[Bartman]

So with 2lbs of CO2 escaping out of the airlock, does this increase my carbon signature? I guess I should plant some hops to offset the carbon.

 

[Killer_Robot]

Hops are certainly green. Or rather, if they're not you shouldn't use them.