Dissolved Oxygen Meter

[barneey]

Just a quick update on this one....

Over the weekend I kegged 2 cornies worth of pale ale, fermentation went fine and no problems incurred.

Today I listened to a podcast by the brewstrong network http://thebrewingnetwork.com/shows/589 (fast forward thru the first 10mins odd just crap talk) anyway there view was slightly different on the bubbling of oxygen thru the wort and the head space plays an important part. Anyone else listened to the podcast? + when bubbling oxygen thru is your lid on or off?

Cheers

[gregorach]

Haven't listen to it, no... But my lid is always on.

[barneey]

For my next "water" experiments I`m going to try the same experiments again but with the lid on to see if the results vary at all?

On the podcast as well it also mentions an interesting idea / point about foaming issues.

[barneey]

Since posting this I`ve also noticed + listened to the updated aeration podcast http://thebrewingnetwork.com/shows/771

[Lars]

Check this out.
http://www.homebrewtalk.com/f51/cheap-e ... get-68218/
I've made one but only tested it with water. A section of 10mm OD copper with a 1mm hole drilled, inserted in the middle of my 1/2" flexible hose from my buffalo boiler ball valve. Had to reduce the flow from max to avoid water coming out the hole. Hope to test it with a brew this week.
Wish I had a DO meter to test it thoroughly....
Its a nice neat low tech idea

[jaybie]

You can get DO electrodes relatively cheaply from Sentek (http://www.sentek.co.uk/dis.html). The galvanic ones are maintenance-free and last about 2 years. they produce a voltage depending on the DO level which could possibly be read using a sensitive voltmeter. The range is 0V for zero oxygen to about 55mV in air. The output needs to be adjusted for temperature but they provide a graph and we all own a calculator.

JB

[barneey]

The problem / summary I came up with after a few other experiements, was that yep its fairly easy to read how much oxygen is disolved in water using a stone / set time / set flow rate. Its what happens at the top of the fermenter, ie sealed area filled with oxygen and the exchange between the two, that becomes more difficult to measure.

When I get around to doing somemore experiments, I`ll bubble the o2 through the water with sealed top, let it sit for a day and then take a measurement.

[Martin G]

Where can I get a disposable oxygen cylinder, regulator, flow meter and pipe. I see that H&G do the scintered stone.

[barneey]

the flow meters can be bought from http://www.coleparmer.co.uk/Product/Poc ... U-32500-80

I use a welding tank for my o2 supply, works out cheaper in the long run, but a pita for storage

[Martin G]

Thanks, that solves the flow bit and I found a welding site that sells disposable oxygen and a regulator. Do people just use tubing to connect the bits together? Also I notice that the H&G scintered steel is 2 micron, is that small enough?

[barneey]

For stones Ive used both the 2 & .5 stone, both work but I now only use the .5

For tube normal silicone hose works fine.

For best results when bubbling o2 thro the wort leave the lid on as much as possible, ie head space has o2 in it.

Experiment with say 30 secs for a 5 gallon batch to start with - try increasing for future brews.

Always rehydrate if using dry or make a starter for the yeast to get things of to a quick start, no point in putting o2 in the wort only for it to fall out before things get going.

See what works best for your set up.

One other piece of advice is to start the o2 off before dipping the stone in the wort + leave on until out again, then give a good blast afterwards, try not to touch the stone and finally clean / boil the thing before use.

Have fun and remember no smoking

[Martin G]

Thanks, do you use oxygen on starters?

[Martin G]

Thanks, do you use oxygen on starters?

[barneey]

Never tried it just a stir plate if required.

Cheers