Comments on The Mad Fermentationist - Homebrewing Blog: Clear Sugar Experiment - Bottling

I am expecting the sugars added for priming to hav...

2010-01-06T16:52:19.036-05:00

I am expecting the sugars added for priming to have a very minor impact on the overall flavor of the beer. 4-5 oz in 5 gallons is pretty standard for priming, but you are right that doesn't sound like much from a flavor stand point (particuarly for such light sugars) that doesn't sound like much.

So far the few sample bottles I have opened have all had pretty good carbonation, although one had quite a bit of sulfur going on (which will hopefully fade).

The amount of sugar you're using amounts to ju...

2010-01-06T13:58:02.338-05:00

The amount of sugar you're using amounts to just over .25#/5gallons. I'm interested to see how much flavor you get there, and how that would compare to adding the syrups to the primary fermentation after a couple days (as you probably can't boil them all in separate pots and keep them the same).

I wonder if different brands are made in different...

2009-12-23T12:01:26.745-05:00

I wonder if different brands are made in different ways, might be that some contain a bit of water, and some do not.

It will also be interesting to see if the flavors, in addition to the gravities, are identical.

I guess you can't trust everything you hear/re...

2009-12-23T11:39:29.581-05:00

I guess you can't trust everything you hear/read! Thanks for figuring it out for everyone!

Using my scale, measuring cup, and hydrometer, 1 o...

2009-12-22T20:18:15.576-05:00

Using my scale, measuring cup, and hydrometer, 1 ounce of candi or table sugar dissolved in tap water to make 8 oz of sugar solution yielded an identical gravity (1.040 @75 F, 1.042 adjusted). Which is pretty much spot on (1.045) considering my hydrometer reads pure water at ~.997, but they are the same which is really the only thing that matters here. Feel free to repeat the test yourself, but that is good enough for me to call candi sugar "essentially" 100% sucrose.

I don't have any more corn sugar on hand, so I can't test that one.

I could be wrong, but I've heard that from mul...

2009-12-22T16:33:45.855-05:00

I could be wrong, but I've heard that from multiple sources. Table sugar is mostly pure sugar, candi sugar crystals are Sugar/Water crystals. I've consistently read that it gets a lower ppg than table sugar. An easy way to test would be disolve an equal weight in water and just use a hydrometer to measure it (or probably a Brix refractometer). In the BN podcast Randy Thiels says that didn't like using rock sugar because of the high water content (infact makes it prone to mold) resulting in inconsistent yield. He infact calls it "sucrose with extra water content. Also it was a pain to disolve and he got no flavor difference from corn sugar or sucrose. (Sunday Session, 5/20/2007 around 1:04:00 or so).

You're partially right about the difference between sucrose and dextrose. Forgive me if this is technical. As far as adding the water, that wouldn't cost any energy. Hydrolysis of a glycolytic bond is an exergonic reaction (energetically favorable, gives off energy) and just needs a catalyist (sucrase enzyme) to bring it about. It becomes higher yield than dextrose, because the same amount of energy yielding sugar has a molecular weight of 340 as a disacharide and 360 as a monosacharide. However, that's only a 5% difference in weight, but there's a 15% difference in CO2 generation (http://www.brewery.org/library/YPrimerMH.html). Since CO2 generation is directly proportional to the amount of fermentation, I was guessing that it was a difference in fermentability of fruc and gluc. However, reviewing my bochem text, they yield the same amount of EtOH and CO2, so I bet it's because there is some water in the dextrose crystals, making them even heavier than they should be (and thus lower yield). This would suggest that BeerSmith is wrong that both have the same ppg, and we should also do the hydrometer/refractometer test on them!

As far as I am aware sucrose gives more gravity an...

2009-12-22T15:18:16.687-05:00

As far as I am aware sucrose gives more gravity and CO2 than glucose because it gets a water molecule added onto it as part of the fermentation process (C12H22O11 + H2O → 4 CH3CH2OH + 4 CO2 ). Most priming sugar calculations suggest using 15% less sucrose than glucose for the same amount of carbonation.

As for the candi sugar as far as I was aware it is nearly 100% sucrose, although I certainly could be wrong (I didn’t check the gravity numbers as part of the experiment). It would be hard for it to be more than a tiny bit water because it is so hard, more water and it would be at a softer candy making stage (softball, thread etc…). This chart (http://www.baking911.com/candy/chart.htm ) suggests that the hard crack stage isn’t reached until 99% of the water is removed from the sugar.

I'm not sure the candi sugar will behave the s...

2009-12-22T13:42:56.670-05:00

I'm not sure the candi sugar will behave the same. The sugar part of clear candi sugar is just sucrose, but it's got a higher water content per weight. According to BeerSmith, Clear Candi sugar has 36 points per pound per gallon, while table sugar has 46ppg. I think it'll end up being a little undercarbonated. I can't think of any references to this off the top of my head though I know they talk about this on the Ommegang/Randy Thiel episode of the Brewing Network in 2007 when he explains why he doesn't use clear rock sugar.

On the other hand, corn sugar has the same ppg, but since it's dextrose (monosacharide basically glucose) instead of sucrose (disachharide of glucose and fructose), I think it provides slightly more CO2 as it doesn't require energy to break down the disacharide. I don't know as much about that. I think palmer explains it pretty well if I remember correctly.