nerd review: sodastream
We just got a new "sodastream" home soda maker.
In terms of its output, I like the thing. Trivial to make seltzer. We're already experimenting. The vanilla soda was great, and the cinnamon soda was interesting, but I really think I'll mostly drink seltzer.
The thing that's really impressing me is the design, though. There are safeguards that ensure you use just the right amount of pressure, that it doesn't explode when you remove the bottle, and that you know when you're done, but all that's used is physics. There's no electricity, no little lights, no meters to read, nothing like that.
So the way it basically works is there's this thing you screw the bottle into, and it's on a hinge. You have to open the hinge to put the bottle in, and then weight makes it close again. You press a button that opens the link between the CO2 tank and a hose that goes into the bottle. When the pressure gets to the right point... there's some kind of gasket or something that starts to release the pressure, and it farts (they call it buzzing, but the machine clearly farts). So you stop. But that's not enough for normal carbonation. For the default level of carbonation, you repeat that until it farts 3 times. They tell you in the book that it's okay to do it more or fewer times to adjust the desired level of carbonation.
As an aside, that part really reminds me of the homemade fermentation lock I made when I was making homebrew mead. I put balloons on the tops of 2-litre bottles. As CO2 was produced, they inflated, until it got to the point where they burped, quickly letting CO2 out without letting O2 in (unless there was a balloon failure, which happened a few times, especially early on). By varying the number of rubber bands I used to hold on the balloons, I altered the amount of carbonation that the resulting mead had.
So anyway then you're done, but you can't get the bottle out unless you move the hinge again. And as you do that, the pent-up pressure inside the bottle is released safely, in some back part internal to the machine, so when you unscrew the bottle there's no change in pressure and no explosion.
They managed to make it pretty foolproof just by using physical properties, physical design. It's neat.
In terms of its output, I like the thing. Trivial to make seltzer. We're already experimenting. The vanilla soda was great, and the cinnamon soda was interesting, but I really think I'll mostly drink seltzer.
The thing that's really impressing me is the design, though. There are safeguards that ensure you use just the right amount of pressure, that it doesn't explode when you remove the bottle, and that you know when you're done, but all that's used is physics. There's no electricity, no little lights, no meters to read, nothing like that.
So the way it basically works is there's this thing you screw the bottle into, and it's on a hinge. You have to open the hinge to put the bottle in, and then weight makes it close again. You press a button that opens the link between the CO2 tank and a hose that goes into the bottle. When the pressure gets to the right point... there's some kind of gasket or something that starts to release the pressure, and it farts (they call it buzzing, but the machine clearly farts). So you stop. But that's not enough for normal carbonation. For the default level of carbonation, you repeat that until it farts 3 times. They tell you in the book that it's okay to do it more or fewer times to adjust the desired level of carbonation.
As an aside, that part really reminds me of the homemade fermentation lock I made when I was making homebrew mead. I put balloons on the tops of 2-litre bottles. As CO2 was produced, they inflated, until it got to the point where they burped, quickly letting CO2 out without letting O2 in (unless there was a balloon failure, which happened a few times, especially early on). By varying the number of rubber bands I used to hold on the balloons, I altered the amount of carbonation that the resulting mead had.
So anyway then you're done, but you can't get the bottle out unless you move the hinge again. And as you do that, the pent-up pressure inside the bottle is released safely, in some back part internal to the machine, so when you unscrew the bottle there's no change in pressure and no explosion.
They managed to make it pretty foolproof just by using physical properties, physical design. It's neat.