Reducing DO on small canning line

[u/Historical_Water3060]

I'm running an ABE craftcan 35. I have been able to get it down to around 30ppb(~40ppb shaken) pickup but occasionally it that might get up to 90ppb pickup (~100ppb shaken). These are a few of the areas I've looked at to reduce DO:

1. FOB: (this machine uses a CO2 jet as it's filling to create foam). If that's needed for the specific beer I will use it for the minimum time to create a good FOB. I recently tried adding around 2ibu of tetra on stransfer to BBT to improve the quality of foam and had my best DO numbers yet.

2. Fish eye bubbles: Tetra may help with this, but in the past the filler has been prone to filling with fish eye bubbles. Not sure how to eliminate this. Wild goose selltheu DO buster which includes a foam scraper to break these bubbles before the lid drops on. That seems pretty interesting. Anyone have experience?

3. Can purging: increasing it from 3.5 to 5 sec didn't seem to reduce DO. I've read that a slower purge by restricting the CO2 flow might be worth investigating to reduce gas mixing. We have a CO2 tunnel but I haven't adjusted that yet.

4. Carbonation: i leant towards a higher carbonation previously to help reduce DO. I reduced is a bit because I thought the finished product was too carbonated. I never saw very obvious impact on DO but I think the ability to form a better FOB helped.

5. Fill speed: this machine uses an inline pressure sensor to maintain consistent tank pressure and fill speed. I can adjust the pressure to change the flow rate but I haven't worked outt if there's anything worth changing.

Keen to hear the experience of others and any tips which might help me.

Cheers

[u/HoppyLifter]

Tracking DO throughout the entire cold side process is important. I run an American Canning AT-1 and for me the most important aspect for protecting against DO is my foam stability in the beer itself. Capping on a solid, dense foam cap has proven to yield me the longest shelf life for my beers.

[u/yazoobrewmaster]

Our CFT rotary line has a bubble breaker that breathes a slow stream of co2 down as the can passes to break the fisheye air bubble. That fisheye is all air, you want to displace it with co2. Then there is a laminar jet of co2 between the lid and can as the lid goes on. If you can make something like that it probably would help a lot. But 40 ppb is very good for an inline machine.

[u/turkpine → u/yazoobrewmaster]

I was just going to say the same thing about our CFT.

But I’m shocked you’re getting 30 ppb with an inline, that’s incredible!

[u/Ziggysan → u/turkpine]

Agreed - that is really good work.

[u/Ziggysan]

Are you rinsing your cans with ionized air or with water? If water; swap it out for IA - you should see a decent drop.

Second all the comments on dense foam and foam stability. Tetra and/or Hexa hop extract may help, but be careful about overdosing. 

You may want to look into using hot water (>85c) to induce foaming as its going to really bust the gas out of solution based on agitation and temperature difference vs just agitation (Hat Tip to Wayne Wambles ex Cigar City for this one). IME it leads to dense foam and no fisheyes and is way cheaper than a liquid N2 doser. 

If you have the money, contact Chart for a liquid N2 system. 

[u/Historical_Water3060 → u/Ziggysan]

We aren't using any type of rinsing. I'll look into the hot water jet. Thanks

[u/turkpine → u/Historical_Water3060]

I believe that u/Ziggysan meant hot water jet into the can, which I’ve only seen successfully work on bottles.

Rinsing with air or water is an important step in prepping cans to be filled. I prefer air over water but either is beneficial

[u/striker4567 → u/turkpine]

We use a jetter on cans and it works extremely well. We use a co2 scraper to blow the fish eyes away.

[u/Ziggysan → u/turkpine]

I did mean a hot water jet into the already filled can or bottle; thanks for helping clarify! I've seen success in both bottles and cans -but you have to adjust the pressure and volume of water depending on the surface area you're trying to foam out. 

[u/Historical_Water3060 → u/turkpine]

Yep I understood that, I've worked with them before. He also asked about can rinsing.

[u/Historical_Water3060]

Another couple variables I forgot to mention:

Fill volume: filling to approx the correct volume seems to have worked best as a balance between foam and not leaving excessive space in the container. Thoughts?

Lid application: my lids slide on well before the seamer and are held down by a floating rail. My concern with this is that it's pushing out most of the foam and in the few seconds before seaming, any foam inside the container is collapsing and allowing oxygen in. I've thought about slightly raising the rail height so the lids sit on top of the foam loosely then are pushed down at seaming. I just have to find a balance so the lids don't fall off as it moves.