By: Jake Weesner, Codi Field Technician
I recently I stumbled upon some literature from the mid 70's on this exact topic and it is always funny to see how much things change, as well as how much stays the same. What's changed in the last 40 years? BPA can liners, pull tabs are illegal in most states, ends with compound, etc. When we look at what has stayed the same, it almost goes without saying. Seam integrity, DO reduction, shelf life, the list goes on! If we really felt like it, we could take this conversation all the way back to World War 1 with canned soup for the boys, and again, would quickly realize how similar the process has stayed down through the years. But this isn't a history class, so feel free to chew gum and pass notes.
To call this the "fundamentals of canning beer", is significantly more black and white than what it will end up. Didn't mean to be a tease, it just sounded better as a heading. If I am being more succinct, this is the order of operation that your attention to detail will reap the most rewards when you're on the canning line. In this specific order:
1) Fill Level
2) Foam Quality
3) Speed
During a canning run, keeping these 3 points in highest attention, and considering them at all times in this order will often save you from issues after the fact. Many operators will start the run with the machine red lined! Just hauling! Only to be about 15 cases in and the pack-out team has a pile low fills, dents, and bad seams. When you are starting a run, first and foremost should be the fill level, ensuring you have consistency. Moving then to foam quality to lock down the shelf life and DO reduction we like. After those first 2 steps are running the way we like, then we pick up the pace. If we start to see changes in fill levels or foam, then we slow down, regroup, and assess the cause. Let's go through these individually:
Fill Levels -
I have spent time with Brewers and Packaging Managers that will have the high/low fill window so dialed in for every beer they run that the equation looks like Tesla's diary. On the flip side, I've had someone ask me 150 cases into a run "how low is a low fill?" Obviously the answer is in there somewhere, the most efficient, economical, quality answer to be exact. For this example, and really for the rest of the time, we are going to be using a 16oz Pale Ale as our constant throughout. A standard 16oz can, filled to the absolute brim, has the ability to hold pretty much exactly that, 16oz of fluid, give or take like .06 fluid oz. We refer to them as 16oz cans, we order them that way at bars and hockey games, we assume that's how much we're getting. This is not the case, nor do we want this to be the case. Every can we fill needs some element of head space. I'm not talking about a bag of potato chips kind of head space, that would be a DO bomb.
To really determine what range we need to be in, we first need to standardize our measurement system, and while opening a can and pouring it into a measurement vessel is a rather exact process, that can is now loss. This is why we weigh them. Check this sick chart I made for a solid reference point when seeing where your beer should land.
Using our earlier example of a Pale Ale, let's say that it finished around 1.012 for specific gravity, this means that the range you are looking for, beer in can, even labelled (most labels weigh around 1g), 500g and above would be a high fill, 485g and under would be a low fill. If You are looking for a more general spec when you're canning, I usually stick by a trusty >485g is low for a 16oz can, and >360g is low for a 12oz can. At the very least, those will get you in the ballpark!
Foam Quality -
Foam, the bane and savior of our shelf life! On a Codi counter pressure filler, we are already at an advantage with our DO reduction from bright tank to fill, but all that advantage goes right out the window if once the fill heads lift, and the cans head toward the seamer, we don't have that great dome of foam. Which now begs the question: What is the perfect dome of foam?
Foam is produced by breakout, or CO2 rising to the surface. Other factors when talking about foam are wort protein, yeast and hop content. Perfect foam is nearly opaque in the sense that there is no differentiation between each bubble. When CO2 leaves solution without the disturbance of oxygen, it retains this tight appearance. When we see cans with bigger bubbles, some call them frog eyes, this is when oxygen is present. Tight foam is where it's at, as long as CO2 is leaving suspension from filler to seamer, oxygen has a very difficult time entering the environment.
In counter pressure filling, we are filling each can under a pressurized environment. When the fill heads lift off the cans at the end of the fill cycle, it's the operator that determines how much the beer breaks out. We want breakout, but we want controlled breakout. By using our run parameters, if we really wanted to, we could have the beer sitting perfectly still when the fill heads lift, I don't know why you would, but we have the technology! In the reverse, if we try to unnecessarily rush the process or don't give the beer a chance to succeed, then we are gonna have beer overflowing all over the place.
Attaining the perfect dome of tight foam on top of the cans is a dance. As the product level and head pressure in the bright tank changes, product temp lowers or raises, ambient temp changes in the pack hall, the list goes on, an operator needs to have an understanding of what will reap the best result for the product they are running. When I'm in the field, especially when training a team for the first time with their new Codi filler, I repeat myself multiple times that we need to let our product tell us what it needs. When an operator gets in the habit of expecting different beers to react the same way every run, they have set themselves up for failure. Day to day, season to season, even batch to batch of the same beer, the product will require specific care to see the tight foam we want. Some products will react better to the off gassing stage to achieve the tight foam we want, while others will prefer the actual fill stage for the agitation needed to see pinnacle results.
Factors like protein content, residual sugar, carb level and temperature all play a role in the decision making process for the operator. This is where, once again, an operator having an understanding of their run parameters, as well as the specific product will be the difference maker all in all.
Speed -
The difference between an efficient run, and a quick run are not the same. Long ago when I was a bartender, my boss at a dive bar I was pulling some shifts told me on a Saturday night: "slow is smooth, smooth is fast". At that time I shrugged it off, I'm looking at 200 thirsty humans, just trying to get down to that nights funk band, no way in hell I'm gonna take my time! It wasn't until a few years later that his statement resurfaced in my brain and I began to understand what he really meant. Slow was not intended as a frame of time, it was meant as a mindset. As a daily life example, I've started my truck 1,000's of times. I don't get into a hurry, nor do I go through the process slowly, I just sit down and let muscle memory take over where the the key goes, where the gear shift is, where the pedals are, even where the seat belt buckle is located. In a matter of seconds, I'm ready to haul ass to legoland! This is what I mean when I say that the use of the word slow or fast is not a frame of reference according to time, it's a mindset. When you hurry, or rush the process, you have opened yourself up to a considerable amount of problems
I have always been on the side of the conversation that I am perfectly willing to have my canning run "take 30 minutes longer" than what management terms the amount of time it should, especially knowing that running 48 CPM vs 55 CPM is all the difference my efficiencies need to be above and beyond expectation. Yes a Ferrari can do 200 MPH, but 98% of the time you're doing 35-45 MPH. The main reason I use this example, losing control at 200 MPH is substantially more likely than losing control at 55 MPH. In the realm of canning, locking in those fill levels and foam at a solid coasting rate of say 48 cans a minute will yield such a higher success rate, while also offering the peace of mind that our quality control integrity has not been compromised. As pressures change, level in the bright tank, etc, that solid run rate offers much more management to your operator. If the goal is just to kill a tank as fast as possible without any integrity control of the final product, then you would probably be better off just kegging it.
Attention to detail will make the difference in almost every facet of life, and when we are dealing with a consumed product, we have no room for error. Use those early stages of the canning run to really dial in, get things flowing smoothly with the highest integrity possible, and then start to gain speed. Notice a change in the finished can weights or dissolved oxygen? Slow down, assess, and adjust. As long as we let the product tell us what it needs, instead of telling our product what to do, your margin of success grows 10 fold! Packaging for life, forklift certified, that's what's up!