Tuesday 24 January 2023

Spike Brewing - Oxygenation Kit - Hands on Review

In a previous post, we outlined the importance of oxygenating wort prior to pitching yeast. Adequate oxygen levels in the wort are vital to ensure that yeast are able to grow and replicate and subsequently produce the best possible flavour profile into the finished beer.

Failure to supply adequate oxygen to yeast can cause issues such as a stuck or incomplete fermentation, or lead to yeast stress which results in undesirable off flavours being generated and imparted into your beer.

It is generally accepted that the amount of dissolved oxygen required in the wort is in the range of 8-10 parts per million (ppm). It is possible to achieve 8ppm of dissolved oxygen in your wort using aeration, which is essentially forcing atmospheric air into the wort using mostly manual methods - think stirring, splashing, shaking or utilising a pond or other pump.

For most fermentations, 10ppm of dissolved oxygen is considered ideal, and the only way to achieve this level of oxygenation is by utilising pure oxygen (from a pressurised cylinder). This of course requires some specialised equipment - namely an oxygen tank and suitable gas regulator, which are typically geared more towards the welding or medical industries.

Oxygen tanks are easy to come by, however oxygen gas regulators in our experience are a little problematic. The more affordable ones either have no gauge to measure pressure, or have a gauge with a scale far too large for the relatively low volumes and pressures required to introduce oxygen to wort. This makes it difficult to determine with any level of accuracy exactly how much oxygen you're introducing into your wort.

Oxygen gas regulators used in the medical industry are more applicable as they measure and control flow rate as opposed to pressure, however they are often incredibly expensive making them cost prohibitive to homebrewers.

Milwaukee based Spike Brewing have engineered and released an oxygenation kit that gives brewers an easy to use and affordable option for oxygenating their wort to ensure the best possible yeast health and fermentation outcomes.

We got our hands on one for a review and to put through it's paces so let's take a closer look.

The Spike Oxygenation Kit Box Contents

Opening the box and we've got the following items included inside;

  • Oxygen regulator with attached silicone hose and gas ball lock disconnect
  • Carbonation stone in an integrated 1.5" stainless steel tri clamp housing
  • 1.5" tri clamp and seal
  • Gas ball lock post

As you can see it's an all-inclusive kit and has everything you need to get going, with the exception of an oxygen cylinder (more on that later).

The regulator itself is coloured black with an integrated gauge to show the current pressure in the oxygen tank, as well as an adjustment dial at the top where you can set the flow rate. The body feels sturdy and solid, and the adjustment dial at the top has a tactile feel as each flow rate selection is engaged.

Spike O2 Kit Regulator with pre-attached hose and gas ball lock disconnect

An integrated gauge with a coloured scale ranging from 0-600psi gives a visual indication on how much  gas pressure is left in your oxygen tank when connected to help avoid any surprises with unexpectedly running out. Time for a new tank or a refill when you hit the red zone!

Spike O2 Kit Regulator

The silicone line and gas ball lock disconnect all come attached with stepless clamps which is great to have straight out of the box and saves some mucking around with assembly (and all but eliminates the chance of oxygen leaks from incorrectly installing or not securing clamps fully).

The carbonation stone is an optional extra (you can buy the oxygenation kit with or without the carbonation stone included), and utilises a 1.5" tri clamp connection to attach to your fermenter. This standardised connection means it can be used on any fermenter with a suitable 1.5" tri clamp port. The housing is of course made of stainless steel so is nice and shiny and looks great. The carbonation stone itself is quite long, taking up the majority of the depth of the housing it sits in, which no doubt aids in its effectiveness.

The Spike O2 Kit Carbonation Stone

If you already own a carbonation stone then you can of course attach the Spike Oxygenation Kit O2 regulator to it directly using silicone hose, or using a ball lock disconnect.

All that's left to do for assembly is attach the gas ball lock post to the carbonation stone. Spike recommend a few wraps of teflon tape around the post thread to ensure a leak free seal. Once this is done the carbonation stone is then attached to the fermenter using the previously mentioned 1.5" tri clamp and seal. It's also recommended to submerge or spray the carbonation stone with a phosphoric acid based sanitiser solution (like Star San) prior to installing in order to avoid any risk of infections being introduced by the stone. Easy.

Some teflon tape around the ball lock post thread to ensure a good seal

Next, we ensure the flow rate is set to 0 on the regulator, then attach the oxygen cylinder. We sourced a Bernzomatic branded oxygen cylinder (red is the standard colour for small oxygen tanks like this) which are relatively cheap and available from most hardware stores. The thread used is a CGA600 type and this tank has a capacity of 40 grams. Designing the kit to use these small and relatively inexpensive cylinders was a great idea as it makes them easily accessible to homebrewers.

Spike O2 Kit with 40g Bernzomatic oxygen tank attached

The cylinder is screwed onto the regulator using a reverse thread (turning counter-clockwise) - you may hear some hissing from the cylinder as the regulator engages, but if you continue turning it stops quickly so the losses are negligible.

Connect the supplied ball lock disconnect to the gas post of the carbonation stone, and we're ready to go. If you have the carbonation stone installed on the end of a valve then you will need to open this valve to allow the wort to submerge the carbonation stone. Installing it on the other end of a valve in this manner is probably a good idea, as it means that after oxygenating you can shut off the valve then remove the carbonation stone - otherwise you'll have to leave the carbonation stone in place throughout the entire duration of fermentation before it can be removed and cleaned - which may be a little more involved after being covered in wort, yeast and trub for a week or two.

It's worth mentioning the timing of oxygenating your wort as well. It's important that your wort is oxygenated after your wort has been cooled down to yeast pitching temperature, but prior to actually pitching your yeast.

There are a lot of variables that determine how quickly and how much oxygen is absorbed by the wort - like gravity (sugar content) and temperature (low gravity and temperature wort will absorb gases more readily than high gravity and temperature wort), but Spike recommend a flow rate of 1/4 litres per minute (lpm) for a duration of 30 seconds per gallon of wort as a good starting point. If the flow rate is too high the oxygen will simply bubble to the surface and come out of solution rather than remaining absorbed. Too little flow rate and you won't oxygenate your wort sufficiently. If in doubt, err on the side of caution and leave it a little longer - over-oxygenating is generally considered less of an issue compared to under-oxygenating your wort.

Spike O2 Kit Regulator and Carbonation Stone

Based on Spike's recommended flow rate of 1/4 lpm, oxygenating a typical 5 gallon (19 litre) batch would mean running oxygen through the carbonation stone for approximately 2 minutes and 30 seconds - certainly much faster than any aeration method. Compare this to aerating using an aquarium pump which takes anywhere from 20-30 minutes, which at best will get you to 8ppm and you can see how much more efficient using pure oxygen with the Spike Oxygenation Kit is.

Spike estimate up to 200 gallons (757 litres) of wort can be oxygenated using one of these tanks which is further evidence of the efficiency of oxygenating with the Spike kit.

Measuring the amount of oxygen absorbed in a fluid requires the use of a dissolved oxygen meter, something we don't have access to so we're happy to heed the recommended 1/4 lpm flow rate from Spike who have done all the testing and heavy lifting on this for us. However, there are other flow rate options available on the dial too - 1/32, 1/16, 1/8, 1/4, 1/2, 3/4, 1, 1.5, 2, 3 and 4 lpm are available on the adjustment dial if you're feeling adventurous or wish to utilise different flow rate settings.

The video below gives an idea of what the oxygenation process looks like using the carbonation stone submersed in liquid. We did this test in water so it's easier to see. Even at the relatively low rate of 1/4 lpm, you can see there's a lot of bubbling activity as the oxygen passes through the carbonation stone into the water.

The carbonation stone itself isn't just a one-trick pony either. As the name suggests, you can also use the stone for carbonating as well as oxygenating. Carbonating happens after fermentation has been completed and adds the desirable fizziness to your beer. The process for carbonating is basically the same as oxygenating, except you are connecting a carbon dioxide gas source (using a carbon dioxide gas cylinder and regulator) to the carbonation stone instead of an oxygen gas source. Using a carbonation stone is a faster way of achieving the desired level of carbonation in your beer as opposed to the typical method of having to pressurise the headspace of your serving vessel (typically a keg) then waiting for the gas to be absorbed from the headspace into the beer.

Cleaning is a breeze as well. Spike recommend cleaning the carbonation stone by soaking in powdered brewery wash (PBW) or similar, followed by a warm water rinse. You can then purge the stone by connecting your oxygen (or CO2) tank to it on order to remove any residual fluid from the porous stone, followed by a quick spray of sanitiser prior to storing for next use.

Overall we think the Spike Oxygenation Kit is a great product. We like the option of being able to purchase the kit with or without the carbonation stone (in case you already have one) or wish to use a carbonation stone that doesn't feature a 1.5" tri clamp fitting. Spike providing recommended flow rates and durations for oxygenation make it simple to figure out how long you need to oxygenate for to achieve optimal results is also incredibly beneficial. We also appreciated the hose and ball lock disconnected coming attached and clamped together meaning the kit is essentially plug and play - always a bonus and all but eliminates the risk of frustrating leaks from incorrect assembly.

Currently for sale on the Spike website at US$85 for the O2 Kit (regulator and gas ball lock disconnect), and US$165 for the O2 Kit + Carbonation Stone it represents good value in our opinion. All the equipment is of the highest quality and is no doubt built to last, but keep in mind an oxygen tank still needs to be purchased separately as well to get going, plus you can also use the carbonation stone for carbonating as well as oxygenating.

You'll also need a couple of other bits and pieces to get the most out of the kit if you're using the carbonation stone. Some thread tape for attaching the ball lock post to the carbonation stone is strongly recommended, and we also recommend installing the carbonation stone onto a 1.5" valve to allow for faster and easier removal after you're done oxygenating.

There's no doubt that oxygenating your wort is a crucial part of making the best beer possible, and the Spike Oxygenation Kit provides an effective and user friendly way of achieving it, especially at the homebrewing level. In our research we struggled to find other oxygen regulators that connect to the small oxygen tanks and boast the same integrated gauge and ability to dial in the relatively low flow rate like the Spike unit does.

Unfortunately at the moment Spike only ship to the US and Canada, but we'd strongly encourage anyone interested in their products from outside these countries to reach out to them and ask when they'll start shipping to your country, or if they're working on using any local distributors. 


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Other Homebrewing Equipment Review Articles

The Importance of Oxygenating Wort when Brewing Beer


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