Do You Really Ruin Gelatin If You Boil It? Experiment Time.

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk:

I have been brewing for some 5 years, 2 of those also as a head-brewer at a local brewery. I don’t have any official education supporting my brewing skills, I gained all of them myself, reading forums, books and articles like this, but most importantly, by experimenting. The information you get from other homebrewers can be useful, but as you probably know, you must take it with a pinch of salt. So many times you read posts from people who are claiming something, but then, after some time, you find out they were completely wrong. Sometimes the wrong information just robs you of your time, sometimes it ruins a brew or two, or slows down your progress. Some of these rumors are so widely spread that the counter-information stands no chance. One of the very common rumors is that you mustn’t boil your gelatin solution (that many of us use as a clearing agent), because you DENATURE the proteins present and it no longer does its job. However, as everybody knows, it is a good idea to sanitize everything that touches the beer in its cold stage, so being able to boil the gelatin would really be convenient. This is the reason for me publishing this article, to bring (what seems to be) true to the masses. Just a little disclaimer, I try not to be a hypocrite, so I admit right now that all you read in this article are just my theorems and information I got from the internet, often simplified, as well as an experiment. There are, however, is some really nice evidence that supports some of them.

What is Gelatin?

It is a protein substance derived from collagen. Collagen is the main structural protein in bodies of animals. It is insoluble in water, but at certain conditions, it can be broken down by water molecules, an irreversible process called hydrolysis. And this is how gelatin is made. Gelatin is to collagen is what dextrins are to starch. The collagen is usually sourced from animal skin, bones, and hoof as these are the most collagen-rich parts. It has to be extracted first to get rid of fat, minerals and other substances, but the actual breakdown into gelatin is then done partial DENATURATION by BOILING it in water. It is then even sterilised by heating to 140°C (375°F) and dried to the solid form.

How and Why Gelatin Works?

First, let’s talk terminal velocity of spherical objects in fluid (yes, it’s physics and yes, it’s beautiful). Now this will be very inaccurate due to million kinds of little simplifications here, but still sufficient to give you a point. Imagine two spherical objects (both the same material) of different sizes. In vacuum, they are going to fall at the exact same speed (accelerating, actually, but at the same rate). In fluids, things get much more complicated, as the drag comes into play. The bigger ball obviously has more drag, but it is also heavier, in fact, so much heavier that it counterbalances the drag difference and the bigger ball is falling faster than the small one. At some point (rather quickly) both balls reach their terminal velocity and they no longer accelerate, they fall at constant speed. This terminal velocity is given by this formula:
In the equation, everything except R (which is the ball radius) is constant.
See the power of it? Ball 10 times the diameter is going to fall 100 times faster.
Now the balls are the tiny little particles that make your brew cloudy. Yeast is one kind of these particles and while it is by no means the tiniest, it is still so small that it’s terminal velocity only allows it to fall very slowly. It has, however, one very useful feature, the feature called flocculation. Some strains (Fuller’s for example) flocculate so well, that you can see chunks as big as 10mm in your starter. And as the formula higher up says, the bigger the particle, the higher the settling speed. This is why Belgian powdery strains take ages to settle. A bigger problem, however, comes with particles smaller than yeast (they are usually proteins). They are (and thus their settling velocity is) so incredibly small, that they seem not to settle at all. They don’t even flocculate. What’s more, some particles are even smaller, so small, actually, that they are affected by some really minor molecular forces to such an extent, that they really do not settle. These are called true colloids.
This is why you want to add gelatin. Gelatin has a strong positive charge in acidic solutions, which results in electrostatic attraction between gelatin macromolecule and our tiny little haze particles and voilà, the particles suddenly flocculate.

The Experiment

The experiment was rather straight-forward. I bought three bottles of the same cloudy wheat beer (Hoegaarden). I let them cool in my kegerator for 12 hours to a serving temperature of 4°C. I prepared two solutions of gelatin. I decided to try the two extremes, so I diluted the first portion of gelatin (0,5g) in 40ml of roughly 30°C (86°F) water (a full hour of stirring) and I boiled the second portion (0,5g) in 45ml of water (to make up for the boiloff) for one minute.
I then opened two of the bottles and injected 5ml of one of the solutions to each of them and capped them. I gave all three bottles a good shake, so they have the same starting point.

I put the bottles back to the fridge and decided to wait 48 hours for the magic to happen. After 24 hours I checked the progress. Both bottles with gelatin were visibly less cloudy than the untouched one, but not clear yet.
After the 48 hours, I took the bottles out for sampling.

As you can see, the myth is busted. I tasted them, and I can tell the clear ones were definitely crisper and also seemed to have slightly lighter body and slightly more banana taste to them. The taste difference was similar to hefeweizen vs kristalweizen and I preferred the hazy one. It suited the witbier style better. I should also say that while the beer in the bottle was clear, the sediment was easy to agitate. This applied to both samples.


Boil your gelatin. It is safer, much quicker and makes little-to-no difference. And also, don’t believe everything people say and don’t spread it if you don’t have at least some clues that it is actually true.

Want to Read Part 2? Check Out This Article »

I decided to do an experiment to bring more light into another commonly discussed, gelatin related topic: “Do you have to cold crash before gelatin fining?” While with the last topic, opinions were quite polarized, some people saying boiling gelatin is a disaster, others being on my side, with this one, most people agree cold crashing is recommended. Let’s look how much of a difference it really makes!
What Exactly is a Chill Haze? Every homebrewer knows that sometimes, after putting a warm bottle of apparently clear beer into a refrigerator, the beer becomes hazy as it cools. Generally, some proteins are insoluble in beer, while others are soluble up to a certain concentration if certain...
Robert Solarik
Hi Robert,
You mentioned working for a couple years as the head brewer at a microbrewery. Did you ever use gelatin at the commercial scale? If so, did you have any success getting it to clear your beer similar to biofine or filtering?
Awesome article. I often wondered about this, but never actually boiled my gelatin. Do you know if you can gelatin and prime in one shot? Also do you gelatin your beer cold or warm or does it even matter? I've see english beers that gelatin prior to kegging. I assume it doesn't matter. Cheers! - Thanks for the write up!.
If often thought of using lime jello to prime, clear and add lime flavor to a pale ale but never did so.
Hello. I add gelatin into an already kegged beer. One day before putting beer on tap I put the keg into the kegerator to chill overnight. I then open it, pour the gelatin in and force-carbonate by shaking. The beer drops clear in 2 days, then I just pour the first muddy half pint into a drain if nobody did so already.
You are reading my thoughts, by the way, warm vs cold clearing is on my list of experiments, I will write an article on that soon.
Lime jello you are talking about is probably a pectin based thing, which is something entirely different, gelatin is an animal product, but you can try. However, there is a mass produced beer in my country which is made to be hazy on purpose and I believe they add apple pectin to get the haze and it does not settle in years. I am glad you enjoyed my article, btw the equation is completely wrong here probably due to formatting, you can google Stoke’s law if you are interested.
Good article and experiment. Gotta fix that equation though (maybe have the editor insert an image of the formula to maintain the formatting).
I normally just heat up gelatin til it's hot. But it's boil from now on.
Curious as to why your conclusion is that boiling is safer and faster? And why you are only heating up your non boiled gelatin to 86 degrees? 86 won't pasteurize and also makes it so the gelatin won't dissolve completely or quickly which is why you are sitting there stirring forever. 1 minutes or less (20 second intervals or so) in the microwave will reach about 160 degrees which will completely dissolve the gelatin and completely pasteurize it. Dump it in your cold, kegged beer and you get the exact same results in 48 hours. Completely safe and pasteurized and a lot quicker than waiting for water to boil. Just my 2 cents. But the main experiment for determining whether boiling affects clarity was a success.
Hi Chris,
I’ve never used gelatin, nor any clearing agent commercially, but if you are able to get it into the tank somehow, it should work. However, the taller the tank, the longer it takes, but that’s true for every sedimentation method. For my 5 gallon cornelius it takes 2 days to drop almost clear and maybe 5 days to get absolutely sparkling clear, but I think it’s because the dip tube sucks the settled stuff as it starts at the very bottom of the keg.
i fail to see the point of this one experiment. I just heat up gelatin for 20-30 secs in a microwave and thats it. Much faster then boiling.
Yes! Boil gelatin. In accordance to most manufacture instructions for gelatin I prep for microbiology lab courses, the gelatin is dissolved in 50 degree Celsius water, boiled for one minute, and then autoclaved at 121 degree Celsius for 15 minutes. No harm done. Pictures speak a thousand words though, and your photos are quite definitive.
The point is, many people say if you accidentally boil the gelatin (which can also happen in a microwave if you are not careful), you have to start over, because it loses its properties. This way, I proved you CAN safely boil the gelatin, but you obviously dont have to, its up to your preference. Ive beer using the microwave method before, but I boil now as it allows me to stir and control boilovers better. Again, the boil is not the point, but it can happen and I proved it is not undesirable.
Well, it is faster because gelatin, obviously, dissolves faster the higher the temperature. My point was not that you SHOULD boil gelatin, but that if you do, you do no harm. This is where the faster comes from. The safer comes from the fact that some bacteria and spores can survive rather high temperatures, although it is unlikely. Also, boiling 50ml of water takes some 10 seconds on my stove. But yes, you can use microwave, it makes no difference, I did so before, but I can stir and control boilovers better on the stove. I have chosen the low temperature for the cold sample to make the temperature difference more extreme and so that nobody can argue that even my "cold" sample was too warm. The article was actually aimed at the people who measure the temperature and believe in some magic temperature limit that ruins their gelatin.
So that boiled gelatin, do you shoot it (nearly boiling) into the beer? Or do you let to cool to room temp or colder before injecting it?
Great experiments!
Awesome, thanks for the experiment. I've been avoiding boiling my gelatin based on the myth you cited, but I plan to start boiling it now. In addition to better sanitation, the higher temperature water will carry less oxygen.
Congratulations for te text.
It helps a lot to understand more about the gelatin process.
I want to translate them and share with the brazilian brewers.