What's in your fermenter(s)?

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Nothing but fresh air! I've got a bottle neck, no pun intended, of lack of free bottles to justify(to the Wife) another batch. I am waiting on three cases of 500mL cappable Belgian bottles from my LHBS still or else I would be ramping for another batch of hefeweizen.
I brew 3 gallon batches. I have 3 batches in kegs, 6 more cases in bottles now. 3 more batches in fermenters and another bigger 5 gallon batch I’m about to get back from a club bourbon barrel brew. I have enough bottles to cover all this, but just barely. I have one keg about to kick.

But this is why I started brew 3 gallon batches in the first place.
 
40 liters of Imperial Pastry Milk Stout ( currently at only 9.4% ABV )
25 liters of BDSA ( currently at 9.8% ABV and most likely finished )
25 liters of Sour Ale, which got big addition of fruit
 
I brew ten gallon batches. Smaller batches sound interesting to try different style/recipes/technics but I just brew from recipes I've done over the years with small changes if any. Sometimes I'll split a batch though like in a wheat, I'd flavor one or both differently. I'm always afraid if I brew smaller batches I won't have enough to fill my needs. Everyone is different and that's what makes the hobby interesting and so much fun.
 
5 gallons of Rauchbier starting its diacetyl rest.

20210321_164506.jpg
 
Hey Danimal:

Here's what you might want to try with your Fermzilla/keg setup next time. Start with an empty sanitized keg, but don't worry about purging it with your CO2 tank. Run a beer line from the gas port of the Fermzilla to the beer port of the keg. Connect your spunding valve to the gas port of the keg...and let the fermentation CO2 do all of the work.

It is important to set up your lines as described even though it may go against logic. Doing so will allow the fermentation gas to leave the Fermzilla and flow through the beer port directly to the bottom of the keg through it's internal dip tube. Since CO2 is a heavy gas it will collect at the bottom while it fills. All of the the lighter air (mainly nitrogen and oxygen) will bleed out of the gas port at the top of the keg controlled by the spunding valve.

Don't worry about not being sure about getting all of the oxygen out...the average fermentation will produce 18 times it's volume in CO2 gas. Or simply put, that keg is going to be purged about 18 times during a brew. I've even "daisy chained" multiple kegs together and this process works great.

Why go through all of this to purge the keg you might ask. Here's the most important reason why:
By doing it this way, the keg's pressure will be equal to that of the Fermzilla. When it comes time to keg, you can use two beer lines to do a gravity transfer of the already carbonated brew from the Fermzilla to the keg. And, there's no need to force carbonate. Simply, do the transfer under pressure, drop the keg into the keezer, cool it down, and you're ready for the first sip. This method allows you to do an entire brew from grain to keg without the need for your CO2 tank.

(BTW, using your setup will not fully purge your keg. By allowing the gas leaving the Fermzilla to force out the 5 gallons of StarSan through the beer port, you are initially introducing air (not CO2) from the headspace of the Fermzilla (approx 3 gallons of volume) into the keg as that initial volume of air is expelled from the Fermzilla. Since air is lighter than CO2, it will immediately rise and become permanently trapped in the top of the keg because all the heavier CO2 is being forced out of the bottom through the keg's dip tube. This phenomena would not happen if you used your CO2 tank to displace the StarSan. You could also just wait a few hours to connect the keg after active fermentation has started. By that point the original air in the Fermzilla headspace would have been been purged by the fermentation CO2.)
 
Hey Danimal:

Here's what you might want to try with your Fermzilla/keg setup next time. Start with an empty sanitized keg, but don't worry about purging it with your CO2 tank. Run a beer line from the gas port of the Fermzilla to the beer port of the keg. Connect your spunding valve to the gas port of the keg...and let the fermentation CO2 do all of the work.

It is important to set up your lines as described even though it may go against logic. Doing so will allow the fermentation gas to leave the Fermzilla and flow through the beer port directly to the bottom of the keg through it's internal dip tube. Since CO2 is a heavy gas it will collect at the bottom while it fills. All of the the lighter air (mainly nitrogen and oxygen) will bleed out of the gas port at the top of the keg controlled by the spunding valve.

Don't worry about not being sure about getting all of the oxygen out...the average fermentation will produce 18 times it's volume in CO2 gas. Or simply put, that keg is going to be purged about 18 times during a brew. I've even "daisy chained" multiple kegs together and this process works great.

Why go through all of this to purge the keg you might ask. Here's the most important reason why:
By doing it this way, the keg's pressure will be equal to that of the Fermzilla. When it comes time to keg, you can use two beer lines to do a gravity transfer of the already carbonated brew from the Fermzilla to the keg. And, there's no need to force carbonate. Simply, do the transfer under pressure, drop the keg into the keezer, cool it down, and you're ready for the first sip. This method allows you to do an entire brew from grain to keg without the need for your CO2 tank.

(BTW, using your setup will not fully purge your keg. By allowing the gas leaving the Fermzilla to force out the 5 gallons of StarSan through the beer port, you are initially introducing air (not CO2) from the headspace of the Fermzilla (approx 3 gallons of volume) into the keg as that initial volume of air is expelled from the Fermzilla. Since air is lighter than CO2, it will immediately rise and become permanently trapped in the top of the keg because all the heavier CO2 is being forced out of the bottom through the keg's dip tube. This phenomena would not happen if you used your CO2 tank to displace the StarSan. You could also just wait a few hours to connect the keg after active fermentation has started. By that point the original air in the Fermzilla headspace would have been been purged by the fermentation CO2.)

That’s great, thanks for the suggestions! I’ve only got a 5lb CO2 tank for my 4-tap kegerator and all other operations currently, so CO2 tank savings are big for me.

I did let fermentation start with an airlock for 3 days which likely purged the air in the headspace. I then threw on the spunding valve and purged the keg. So far I’m having fun with the new gadget! Will try the method you suggested on my next brew.

Dan
 
CO2 will mix with air don't believe that it sits as a separate layer unless it was incredibly cold and still. The molecules are energetic and mix, especially as the flow is turbulent.
If this wasn't the case CO2 in the atmosphere would all be blanketing close to the earth and we would suffocate and have to live pardoxically high in the mountains to get better Oxygenation. Which is not the case.

Regarding the oxygen in the head space of your fermzilla, just let that headspace be vented via the spund valve for a day or so and the yeast will use all the oxygen it wants and the rest will go into the atmosphere. That headspace is small.
Then flush the starsan out of your keg as mentioned above using the fermzilla ferment off gas and you will have the minimum amount of oxygen, even less than the CrabbyOldMan method. Because you are starting with much less O2 in the system, ie little in head space as purged and you don't have a 20 litre keg initially with air in ( so 4litre of oxygen 16 nitrogen approx ).
CO2 is only about 25% more dense than Oxygen and about 37 % more dense than nitrogen.
Density of Air is about 1.27g/l at room temp assuming it is dry. The air isn't dry unless you filled your keg with medical air prior to flushing it ( which you don't) .
 
Hey DuncB:

Interesting reply, but not entirely correct. Let's start with the molar mass of oxygen as 15.9994 and that of carbon dioxide as being 44.0095. As you can see CO2 is quite a bit heavier than oxygen. This is confirmed if you use the density number you reported.

Now let's play a little "Mr. Science" and think of an oxygen molecule as a 2" ping pong ball and a carbon dioxide molecule as a 2" wooden ball. Now take 100 of each and toss them into a box and stir them up. Now ever so slightly jiggle the box for 30 seconds. Now just using intuition, where will the heavier wooden balls and the lighter ping pong balls be after the jiggling?

You are correct that if an outside force is introduced (such as vigorous stirring), the the mixture will become homogenous as long as that outside force is present. But, on a molecular level once that outside force is removed the heavier molecules (CO2 in this case) will immediately begin settling to the bottom of the vassal. It take only a short time for that layering to occur.

You are absolutely correct that if there were no stirring of the gas mixture we call "air" on planet earth we would have a layering of those gasses with the heavier gasses at the lowest level. But due to the rotation of the earth causing night and day, the heating and cooling of the earth on a 24 hour cycle produces an incredible amount of continual stirring...it's called wind.

When the Fermzilla and a keg are configured in the manner I described, there is no "wind" introduced to the inside of the keg therefore a layering exists inside the keg. The "burping" of the CO2 from the fermentation into the bottom of the keg via the dip tube is incredibly slow and produces negligible amounts of stirring energy (which dissipates quickly.)

If you need a hands on demonstration in your own kitchen, try putting equal amounts of olive oil and water into a blender and hit "high" for a few seconds. Notice that as long as the blender is turned on, oil and water do mix. But after the blender is turned off, note how long it takes the heavier water to settle at the bottom after the outside force is removed? The same thing happens at a molecular level with carbon dioxide and oxygen, but at a different rate. They don't "stick" together in any manner and the force of gravity on the molecules is constant.

I am only a student of Physics but have lots of years of experience. Since a blog like this is generally not conducive to any sort of real teaching, you may want to check these facts with a local authority on the subject where interaction is present.
 
We could debate this for a long time and the semantics.
But the less oxygen you have in your system at the start the easier it is to get to a lower level, ie don't have that 4 litres of oxygen in your tank have much closer to zero after the liquid displacement purge.
Those gases will mix in a keg, there is disturbance from the CO2 flowing in from the fermzilla and leaving. The hydrophobic nature of the oil discourages it from mixing with the water. But make the oil droplets small enough and they do mix. Milk is a good example.
Buy a Bamix and you can " whip up " mayonnaise in less than a minute.
Gases do stratify, but they also mix at the interface and given time will mix pretty evenly.
 
A strong bitter with EKG and Mandarina Bavaria added at flameout, I gotta get my actual grain absorption rate right in berrsmith since I get way too much wort preboil when using the suggested amount of sparge water and low gravity as a resultat.
This became som sort of best/strong bitter hybrid, but the wort tasted yummy and I think it will become good beer anyway.
 
4 gallons of Kirkland apple juice with half a packet of Cote des Blanc wine yeast and 1/2 tsp of Fermax yeast nutrient. No added sugar in this one, and that's not much nutrient. It should end up just over 6% ABV.

About 6 quarts of strawberry wine made with 1 gallon of water, 4 (18 oz) jars of Aldi strawberry preserves, a pound of frozen strawberries, the other half a packet of yeast, and 1/2 tsp of Fermax. I started both of these on Thursday and they are bubbling away. In a couple of days I will strain the solids out of the wine transfer to glass jugs with air locks. It should finish about 11.5% or 12%. It smells good already; a lot more like fresh strawberries than it should.

I need to get some beer started :) But I spent the weekend planting vegetable and flower seeds, transplanting seedlings into little pots, and cleaning out the light room. The wine and cider will tide me over.
 
Hey DuncB:

Interesting reply, but not entirely correct. Let's start with the molar mass of oxygen as 15.9994 and that of carbon dioxide as being 44.0095. As you can see CO2 is quite a bit heavier than oxygen. This is confirmed if you use the density number you reported.

Now let's play a little "Mr. Science" and think of an oxygen molecule as a 2" ping pong ball and a carbon dioxide molecule as a 2" wooden ball. Now take 100 of each and toss them into a box and stir them up. Now ever so slightly jiggle the box for 30 seconds. Now just using intuition, where will the heavier wooden balls and the lighter ping pong balls be after the jiggling?

You are correct that if an outside force is introduced (such as vigorous stirring), the the mixture will become homogenous as long as that outside force is present. But, on a molecular level once that outside force is removed the heavier molecules (CO2 in this case) will immediately begin settling to the bottom of the vassal. It take only a short time for that layering to occur.

You are absolutely correct that if there were no stirring of the gas mixture we call "air" on planet earth we would have a layering of those gasses with the heavier gasses at the lowest level. But due to the rotation of the earth causing night and day, the heating and cooling of the earth on a 24 hour cycle produces an incredible amount of continual stirring...it's called wind.

When the Fermzilla and a keg are configured in the manner I described, there is no "wind" introduced to the inside of the keg therefore a layering exists inside the keg. The "burping" of the CO2 from the fermentation into the bottom of the keg via the dip tube is incredibly slow and produces negligible amounts of stirring energy (which dissipates quickly.)

If you need a hands on demonstration in your own kitchen, try putting equal amounts of olive oil and water into a blender and hit "high" for a few seconds. Notice that as long as the blender is turned on, oil and water do mix. But after the blender is turned off, note how long it takes the heavier water to settle at the bottom after the outside force is removed? The same thing happens at a molecular level with carbon dioxide and oxygen, but at a different rate. They don't "stick" together in any manner and the force of gravity on the molecules is constant.

I am only a student of Physics but have lots of years of experience. Since a blog like this is generally not conducive to any sort of real teaching, you may want to check these facts with a local authority on the subject where interaction is present.

If you are a student of physics, look up "partial pressures". Your oil and water analogy is irrelevant (no offense.) Gasses do not separate, they mix, albeit slowly. You only get stratification if you are adding more of one of the gasses faster than they can diffuse into each other.
 
  • Apricot, peach sour - 4 more weeks of aging!
  • Centennial Blonde - almost there, just waiting on the sulfur odor to mellow
  • Czech pils, just started active fermentation after a scary 36hr lag with tons of repitched 34/70
 
A strong bitter with EKG and Mandarina Bavaria added at flameout, I gotta get my actual grain absorption rate right in berrsmith since I get way too much wort preboil when using the suggested amount of sparge water and low gravity as a resultat.
This became som sort of best/strong bitter hybrid, but the wort tasted yummy and I think it will become good beer anyway.
A bitter w Mandarina sounds delicious. I’m thirsty now.
 
Brewing another Aussie type lager. I might actually lager this one for a while if I can find freezer space.
 
4.5 gallons of a Pink Elephant clone, been 2.5 weeks now. Really wishing it was a faster beer but it's gonna need at least 3 weeks warm total, plus probably 1 month cold conditioning before it's truly ready to drink.
 
Count me in! The article mentions my favorite Pilz brewers, Heater Allen.

Next on my brew list was a Pfriem or Von Ebert clone (which is sorta close).
 
A NEIPA bubbling like crazy, i will say the best thing about NEIPA is the speed at which they are done, like once fermentation finishes , just gas it at 42PSI for a day and its ready, most beers i do arent ready fast, they kinda need conditioning.
 
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