Yeast Cell Density Meter

[WoodlandBrew]

So basically this is a power or intensity measurement of the reference laser, then compare it using the scattered diffuse light reflected by the yeast in the wort?

Wouldn't this also be affected by the protein in the wort as well? Not sure of relative size or reflectivity.

Trying to remember from my optics lab, but won't there be an upper limit on the accuracy as well? Or is it beyond the range of typical starters?

Yes, that is the basic theory of operation.

Great questions! Yes, accuracy will be limited to a range. With a hemocytometer count you normally do dilutions until you have about 100 cells per box. 20-200 cells per box is pretty much the reasonable limit with a microscope. From our initial testing I think we can beat the microscope in that range. Also, I expect that it will be able to operate beyond that range.

It will be thrown off by protein in the beer. We will do you best to adjust for typical scenarios. This is where comparison to hemocytomer counts will be very useful.

 

[pricelessbrewing]

Good to know, looking forward to product launch!

If nothing more this will be wonderful for giving more accurate estimates and a range of # of cells to expect.

 

[stoneBriar]

Sounds awesome, thanks for the Q&A. Keep us posted on your website also since I've got that in my RSS feed!

 

[WoodlandBrew]

Thanks everyone for your feedback so far! It has been very helpful.

We are looking at different options to power the unit. What are your thoughts on USB, wall power and battery power? What would you want, and what would you expect?

 

[Ben58]

Battery as portability is handy.

 

[Shockerengr]

Battery power is nice if the batteries are replaceable or common.

Otherwise USB is handy because the cords and chargers are so ubiquitous nowadays that finding one is easy...they sell piles at the checkout in the gas station even.

 

[Hermit]

I like the idea of a rechargeable unit. That way you could still go USB.

 

[pricelessbrewing]

Don't go battery unless it's replaceable or a household battery like AA or AAA and not some expensive replaceable one ala laptop or watches. Usb with rechargeable eneloop AA batteries would be pretty nice.

 

[jbaysurfer]

Definitely battery. I'd prefer the USB rechargeable if you were able to get a good quality LI battery in there. But I do have concerns about replacing said battery when it eventually runs out, which, brewery work like this can be kinda hard on batteries IME.

 

[Leithoa]

if you go the USB route for either charging or main power it'd convenient to be able to collect readings over USB.
Optional serial output might be easier to implement at a hardware level though.

 

[passedpawn]

Here's a great model for a device like this. Adding a Li battery, USB port, etc just doesn't make sense here; I don't want to pay more to make it rechargable. I want it cheap, and I'll supply the AA or AAA battery, no prob. I don't think there's much advantage in serial data from the thing since it's a one-time measurement. If it was a process measurement, like measuring ABV or gravity during fermentation, yes, USB or wireless would be cool.

This company, Hanna, has a bunch of identical instruments (the calibration and colorimetry agents are different, but the package is the same).

Measuring SRM is a simple absorbance test through a cuvette. 430nm LED. Photodiode. Simple microcontroller to do the A/D conversion and display something. The package below would be perfect. I have a couple of these types of things at home.

 

[tagz]

Subbed.

 

[WoodlandBrew]

Thanks for all the feedback! We'll do our best to meet your expectations.