I received a nice email recently from a reader David, asking how to add fruit puree to beer. Here’s the original email.
I enjoy your articles very much, and learned a great deal from them. I really appreciate the fact you’re sharing this knowledge.
After reading your article on spunding beer, I’ve a question: If you add fruit puree or concentrates at the end of fermentation, would that have the same volcano effect as it would when dry hopping?
If it does, what do you do to avoid that?
Thanks again plus by the way happy holidays to you and your family,
I always appreciate positive feedback on my articles. Emails like this motivate me to keep writing posts. It’s often hard to write these articles coming up with fresh content.
The reply I wrote had some content I thought others might appreciate. I asked the David, if I could include his original email and the reply I wrote. As I wanted to share the content.
He said he was happy for me to share his original email and my reply…thanks for your permission, it was really appreciated David.
My Reply on How to Add Fruit Puree to Beer
Thanks for your kind words and good to know you’ve found my articles helpful.
Anytime you add something to a beer (which has been fermented), there’s always a chance of CO2 breakout. When adding fruit concentrate/puree to a beer, there’s a few things I like to consider:
1. Liquid Volumes
How big are the volume of the liquids? The volume of beer in your tank and the amount of liquid (puree/concentrate) you intend to add. If you’ve large volumes, for instance in one brewery I worked at, I was adding 220L of puree to 6,500 liters of beer.
In this case I used a centrifugal pump (pictured below). These pumps are self-priming and as I don’t need to open the tank, there’s little oxygen pickup. I usually pumped the liquid being added through the racking arm.
I also used the pump for mixing the puree into the beer after adding it. I would come out of the bottom of the tank and back through the racking arm. As the system is “closed” any CO2 breakout is contained within the vessel itself.
Smaller Volumes – My Reply on How to Add Fruit Puree to Beer
If I’m working with smaller volume; say, 500 liters of beer and adding say, 20 liters of puree or concentrate. I would add it through a manway or port from the top of the vessel. I’d not spund the beer beforehand so, there’s less chance of CO2 breakout.
When adding top a vessel keep the CIP/CO2 arm open (make sure there’s a valve attached). As this allows the beer to go somewhere, if there is CO2 break/volcano as your closing the tank.
Once the concentrate/puree is added, I’d close up the tank. As I like to ferment out the sugars (see point 2), I’d let the suagrs ferment out for say 5 hours and then close the tank and spund at that point.
Letting the beer ferment for a few hours before closing the tank to spund the beer, means less chance of DO pickup.
It might mean you’d need to add top pressure later to get your desired carbonation level, but the whole process is safer this way.
Another option; if you’re going to use puree/concentrate regularly on a smaller system is to buy a very small hopgun. Then use hopgun to add your purees. A hop cannon can be used for many things like adding coffee to the beer, it’s not just useful for hops.
2. Ferment out the sugars in the concentrate/puree
I always like to ferment out any addition I added like this. So, add when the beer is roughly 2 Plato above my predicted terminal gravity.
This way I ensure there aren’t any unfermented sugars in the final beer. If packaging beer has any unfermented sugars, it may make a can/bottle into a bomb. As the sugars can ferment in the package, creating excess CO2.
I guess you may know this already; but as a brewer who takes safety seriously, I felt I need to stress this point.
If you want to add the puree/concentrate post ferment. I’d always filter my beer so there’s no yeast in it. This means the sugars cannot be fermented as there’s no yeast. I do this when back sweetening a cider for example.
Round-up for David – How to Add Fruit Puree to Beer
David, I hope this advice helps and if you have any follow-up questions, please feel free to ask. Also, here’s some further reading which may be useful to you (related to my answer) from my site:
Spunding Beer During Fermentation – Asian Beer Network (although you’ve probably read this one according to your email).
One thing, I’d like to ask please…
Would it be possible to use your original email and this answer as a short article please? I can blackout your name. I think the information here is useful to others so, would like to turn it into a short article with your permission please.
For now, likewise happy holidays to you and your family.
How to Add Fruit Puree to Beer – Conclusions
I encourage people to write to me if they have a question or some feedback. I enjoy chatting with fellow brewers, if I can help it’s great.
I’ve got to where I am in brewing; due to people helping me throughout my career. I like to give back, when and where I can.
As I say, I sometimes find it hard to write posts. Correspondence like this often makes for a good short article, when I get permission from the original emailer to do so.
As I say in the reply, I take safety seriously in a brewery. It’s the same with the advice I give in this post on how to add fruit puree to beer. You’re often working with beer under pressure and already carbonated to a certain level.
CO2 breakout is possible and under the wrong conditions it can be dangerous. So, please be careful. If adding puree through a port or manway please use gloves and safety glasses and have someone with you to observe where possible (especially if you’re up a ladder for instance).
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Thanks for reading and happy brewing!