Best way to measure total emitted weight of fermentation CO2?

[JKoravos]

So my flow meter seems to work to some extent. I ended up having the bubbles go up through a tube of water before going through the flow meter, this means that the bubbles take some water with them, which helps spin the wheel in the flow meter at an even lower flow. The design also makes it so there is a bit of build-up of gas before it releases and goes through the meter. It seems to read at even very low flow.

See figure below from an IPA I brewed. The green line represents the cumulative litres of gas produced. Ignore the other lines. There is a big gap because the power went out and my arduino wasn't saving the figure to memory, so it started at zero again. I took me a while to figure out the memory thing, implement it and get it going again. I doubt the actual number of litres are accurate and I can't yet convert to gravity or alcohol (would need many many more examples to work with). But at the very least, it gives a measure of the progress of fermentation.

I have a couple of these mass flowmeters: Economical Gas Mass Flow Meters for Clean Gases with Optional Display

I just got BruControl set up and it was the first thing i hooked up, I've had these flowmeters for probably 10 years and had never used them. I had bought them for this specific purpose. I had 500cc/min model connected. It seemed to work well but I need more experience with it to understand the precision better. I'll probably just buy a Tilt in the end but I've had these flowmeters for so long wanting to try this that i had to get it set up.

 

[day_trippr]

Hahahaha! "Economical" clearly is not a fixed metric. Woof!

Cheers!

 

[bracconiere]

once again i'm reminded of my 110lb scale that stays on, and is acurate to the 10th ounce...... just leave your fermenter on it.....i think even my 10 gallon batches are only around 80 or so pounds....$27 off amazon...

 

[JKoravos]

Hahahaha! "Economical" clearly is not a fixed metric. Woof!

Cheers!

Well, i got them for $20 each on eBay, so it was economical for me anyway.

 

[crane]

I got one for $45 off ebay, so less economical, but still not as much as a Tilt. I also can't use my Tilt. Despite other people's luck using these in conicals, I cannot get a signal out of a sanke keg once I install the spear.

I just got my new fermentation chamber control panel finished up to work with BruControl, so I will be testing this out on future ferments.

 

[azaxev]

Resurrecting this thread. Anyone was successful getting some data of fermentation jug weight loss ?

I am not looking for automation, just estimate based on weight rather than measuring gravity with refractomer or hydrometer. The scale does not need to be extremely accurate, as weight difference between glucose and ethanol is quite significant. Bathroom scale should work.

Btw. the actual mass of ethanol to released CO2 would be ratio of their molar masses. 46.07g/mol (ethanol) / 44.01g/mol (CO2) = 1.0468.

 

[doug293cz]

Resurrecting this thread. Anyone was successful getting some data of fermentation jug weight loss ?

I am not looking for automation, just estimate based on weight rather than measuring gravity with refractomer or hydrometer. The scale does not need to be extremely accurate, as weight difference between glucose and ethanol is quite significant. Bathroom scale should work.

Btw. the actual mass of ethanol to released CO2 would be ratio of their molar masses. 46.07g/mol (ethanol) / 44.01g/mol (CO2) = 1.0468.

Based on CO2 production calculations here, 20 L of 1.050 wort fermented to 80% apparent attenuation will produce about 878 g of CO2. If fermenting at 65°F, the beer will retain about 0.88 volumes of carbonation or 20 L * 1.977 g/L * 0.88 = 35 g of CO2, so 878 - 35 = 843 g of CO2 would leave the beer. If the fermenter has 5 L of headspace, this will contain about 5 L * 1.977 g/L = 10 g of CO2, so 843 - 10 = 833 g of CO2 would leave the fermenter. 833 g = 1.83 - 1.84 lb.

Brew on