Aerating Wort

A while back we were sent some info on oxygenating wort by Lee from London Amateur Brewers. It has some great information and tips, so we thought it would make a good blog post that brewers can easily refer back to.

Firstly, some background reading:

For oxygenation you need a source of oxygen, a regulator, a connector, ideally a flow meter, some 3/8” beer line tubing (or metal) and a diffusion stone. There are two options I’ve looked at:

Oxyturbo disposable cylinders

These are available in shops or online and can be posted by courier. They are single use. They are sold fairly widely (they are used for welding) and you can get them for about £20 if you buy a few at time and shop around. Here is one https://www.welduk.com/product/oxyturbo-480300-oxygen-gas-cylinder/

They are 1 litre capacity and 110bars, so about 110 litres of oxygen. Roughly – 5 (US) gallon brew of normal strength beer takes 1l/min for 1 minute, twice as long for strong beers. So this should do you 50-100 beers but in reality it was somewhat less than that. A good 30 at least (but I do make 33 litre batches). I did sometimes use it on starters, and for strong worts you can re-oxygenate after 12-24 hours.

Regulators are £25 https://www.welduk.com/product/regulator-disposable-oxygen-cylinder/ or £35 with gauge https://www.welduk.com/product/regulator-gauge-for-disposable-oxygen-cylinder/

They come with a small barb which you might fit some line on directly. Or, there is a JG fitting you can buy, cut off a little of the thread, and it screws on directly. I hear the gauge one takes a JG fitting without any need to saw a bit off.

Flow Meter

You can just run the oxygen so you can just see bubbles when you dip the sintered stone in liquid. But its better to have a flow meter. There are ones that have a valve (£9) or ones that don’t (cheaper). You want it to show up to 2l/min (my first one went 0-5litres). It should be for oxygen, although Argon is close enough for what were doing. The one on the right is much better than the one on the left in terms of build and the smaller range. Both available on eBay.

Plus – easy to order, no deposit, small and compact

Negatives – need something to hold the tank upright really (I used a sawn off measuring cylinder), expensive oxygen

Larger refillable tanks

Available from welding suppliers, I got mine via Adams here https://www.adamsgas.co.uk/product-category/hobby-welding-gas/

So these cost £46 a refill. They are 10 litre 200 bar – the same as 18 disposable cylinders (for the price of 2 of them). However, you have to stump up a (refundable) deposit (maybe £55) and delivery (£12 – but if you’re getting CO2 anyway..) A single stage regulator is sufficient and costs about £27 (so same as the disposable one)

The output is a 3/8 bsp thread so a simple JG connector to 3/8 line works nicely.

Again up to you if you use a flow meter but as the pressure is much higher I think you’d be wise to get one. You can skip that on the disposables (but then you might dump the whole bottle into a brew like Fraser did – so could be false economy). You can buy an Argon flow meter that will screw straight into the 3/8 thread so everything is neat and fixed to the regulator like this, but try and find one that has the right flow range (1-2 litres per minute https://www.zoro.co.uk/shop/welding-brazing-and-soldering/flowmeters-and-economisers/1242-flowmeter-argon-0-14-lpm/

Plus – works out cheaper over maybe 3-5 years, even if you write off the deposit. Tank stands up

Negatives – takes up more room, higher initial outlay.

For both, the oxygen isn’t claimed as food grade, but it often comes from exact the same tank as medical oxygen, it just isn’t tested. Some say it’s worth fitting an inline filter just to catch any oil or particles etc.

You can get compressed stone stones or better sintered stainless steel stones with a barb to fit to 3/8 beer line. Or a nice wand with same barb :  https://www.brewbuilder.co.uk/air-stone-wand.html

Sintered Stone

Oils from your finger can clog these up so don’t touch! I dip the sintered stone in some hot citric acid after each use to ensure it doesn’t clog up with chalk from the water (that did happen initial) and then sanitise the outside of that and the tubing with Starsan. The pure oxygen should kill anything on the inside. Some wrap it cling film after cleaning to prevent dirt/accidental touching.

Final point is that its easier with a conical to use flexible beer line and feed it in through the centre port on the lid, but you can use a metal wand for buckets or small plastic vessels etc.

I think I will try and find a place to site the tank and then run permanent tubing to where I need it, with the flow meter then fixed close to use. Then just plug in the flexible/detachable line/stone when needed.

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