You use a hydrometer on your wife when she sleeps in a bed?!!Mr. No-Tip said:I use a hydrometer.
And sleep in a bed with my wife.
Nah, just kiddding. Sounds interesting. I'll be interested to see if this goes anywhere.
Actually probably accurate to 0.5 of a point, of course you would have to give it an accurate OG to begin with, CO2 correlates directly to the amount of alcohol produced/ sugars consumed by yeast. There is already a doodad on ebay that does the same thing, weirdly it allows the CO2 to inflate a balloon to a certain pressure and release it, counting how many times it is inflated and correlating this to gravity points lost. Obviously these measurements are all dependent on temperature and I note both have temp sensors on board. As long as you can measure temp, volume of CO2 produced, and have an OG, the rest is high school math, an R'PI wouldn't get warm doing the calculation.dent said:Near as I can tell they release the CO2 at a certain measured pressure and attempt to use that release timing data to estimate your fermentation progress. Pulling a long bow with that I reckon.
Check out the thread title and head back to post #1. How much?ekul said:to measure co2 loss you could just weigh the fermenter, no need to measure the amount of gas coming off. Measuring the volume of the gas coming off would be inefficient as the volume would change as the temperature changes. However the weight of the co2 being lost will always be the same.
Quiet Tuesday on the brews?ekul said:well, say you make 23L of beer and its 5% abv. That means you have 1.15L of pure alcohol. density of alcohol is 789kg per cubic metre. 1000L to the cubic metre. 789/1000 x 1.15 = 907 grams of alcohol. Molar weight of alcohol is 46.07g So for a 5% brew you have 19.69 moles of alcohol.
For every 1 mole of alcohol produced you also produce 2 moles of CO2. Molar weight of CO2 is 44.01g.
If you make 19.69 moles of alcohol you make 39.38 moles of CO2. 39.38 moles of CO2 weighs 1733.11g
So for a 23L brew at 5% your weight difference should be 1.7kg. I'm drunk though so someone should probably check these figures.
it would be hard to do this calculation purely from og to fg because your volume will change from the co2 loss. The co2 will have a volume in the fermenter but i dont know what this volume would be. Evaporation loss should be fairly low if the fermenter is sealed. If evaporation was a concern airlocks would go dry several time during fermentation.MastersBrewery said:ok simplistically 23L of 1.050 wort weighs 24.15 kg and 23L of 1.010 wort weighs 23.23kg
at the beginning of ferment you add 7-12G of yeast
Now at the end of ferment we have a crap load more yeast/ trub together probably slight lighter in weight by volume than the sugar that's been consumed. I note the total volume with in the fermenter may have reduced by 50-100ml, most of this I'd write off to evaporation
Most of us write 2L off to losses in the fermenter but a lot of this is liquid with solids (yeast and trub) suspended if we were able to separate these solids I'd say you'd maybe be short 300ml all up. so 22.7l of 1.010 is 22.97kg
It would be interesting to check og/fg fermenter weight
i think i replied to this thread but instead of putting the weight i put the volume of gas that would be released. I saw it again and thought maybe the weight difference would be more of use.ArgM said:Where were you all when the naysayers came at the start!
I'm going to be trialing the scales as well as a bubble counter I've knocked up with my next brew which, having been put off for about a month I think I should do this weekend!
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