OxySense feedback

[Hovercar]

I don't see a lot of talk about the OxySense system for D.O. measurement here. My brewery is looking at purchasing the technology but we were hoping to get some feedback from anyone that is currently using it in their brewery. I've done some reading, talked to their lead scientist and understand the general benefits and limitations of the technology.

However, I want to hear from people in the field actually using it. They have some new tech and have expanded their product line. The dot system is still their main workhorse, but they have developed a piercing needle for bottles and cans that I haven't seen any reviews for. The combination of the dot and now the piercing needle seem to provide a pretty robust system that can measure from 15ppb to saturation throughout the process from wort to packaged product. It seems great but I am having a hard time finding any discussion of the system online.

So is anyone out there using this? What do you think of the tech?

[TL Services]

Compared to other, existing systems (electrochemical and optical) that can measure down to a nominal zero ppb, then the 15ppb threshold seems quite poor.

The technology behind OxySense is the same as other optical meters, ie. light stimulus of a fluorescent spot and measurement of the fluorescence decay rate. Oxysense were one of the first companies to use this instead of electrochemical sensors so they have a good head start on the others.

For me, having worked with a variety of oxygen meters in brewing before my current role, the one drawback is direct measurement of tanks, mains, etc. isn't possible with Oxysense. This means there is a big limitation in its applicability to brewing, where accurate oxygen results are needed from wort onward through the process. There's no point in having really low O2 in final package if, for instance, the beer has already been oxidised massively earlier on in the production cycle.

If you're looking at oxygen measurement for the first time, then a good portable meter would allow you to measure right across the brewing process and, with a suitable piercer, use the same meter to measure in final package.

This has two primary benefits:

Quality - by using the same meter throughout, you eliminate the inherent differences between different instruments and/or technologies. This means your overall level of measurement error will be much smaller;

Cost - simply, why buy two (or more) different systems for specific process areas when one meter will do the job?

The Oxysense system works for measuring in bottles, which was for years its primary function. This and similar systems are widely used in the wine industry for that purpose and have a good reputation in that industry.

Similarly, in brewing, there are 'industry standard' (or at least, very commonly used) meters. These have a good track record and, when comparing data from one brewery to another, allow valid direct comparisons to be made.

I don't want to sound as if I am 'anti' anything, but from 30-odd years experience of the good, the bad (and sometimes the ugly!) I hope I've learned something...

[Hovercar]

KWLSD, thanks for your feedback.

According to the gentleman at OxySense I talked to, measurement can be preformed via a sight glass with a dot installed, so measurements can be taken throughout the process (ie. during transfers). However, like you said, I don't see how it can measure directly from tanks.

I have also been looking at Hach products, but the optical unit (the 3100) still won't be accurate for wort; the sales rep suggested a different handheld unit for that. So in that sense, unless I go with an EC unit, wouldn't I need two pieces of tech anyway?

[TL Services]

You're quite right that the 3100 optical meter can't be used for wort oxygen (unless you buy the high-level version, but you'd also have to buy the low-level one for everything post-fermentation...).

A good EC-sensor meter - and don't forget, Orbisphere and others haven't abandoned these, they're still current and still good - will allow you to measure right through the process.

There are other benefits of EC sensors too - for a quick check, all they need is to be attached to plain mains cold water and should read around 8-9ppm, depending on the exact temperature. This is something that can't be done with an optical meter, which gets to 2ppm then goes over-range.

Servicing an EC sensor takes under an hour and calibration is done in air; no special calibration standards, just some basic tools that come with the meter and consumables that are a few $'s.