Using Gelatin to Clear Homebrew A Guide to Crystal Clear Beer
Whenever I think of gelatin, I think of horse hooves. That's right, horse hooves. From the knacker's yard. Gross right?
Well I say jelly is jelly, food is food, and if I need to use the foot of a horse to clear my beer and reduce sediment in the bottle I will!
So, here's the guts of using gelatin to clear your beer.
Basically, gelatin acts as a fining agent. It combines with the 'leftovers' of the beer brewing process and they fall to the bottom of the fermenter thus clearing the beer.
The Science: It works via electrostatic attraction. Yeast cells and haze-causing proteins are negatively charged. Gelatin (collagen) is positively charged. When you introduce gelatin, it acts like a magnet, clumping these particles together until they are heavy enough to drop out of suspension rapidly.
So how much gelatin should I add to my beer?
Less is More
Many beer brewers have found that between half and a whole teaspoon per 23 litres or 5 gallons will be a sufficient amount. You will probably get diminishing returns if you use much more.
Over-fining can result in "fluffy" sediment bottoms that are easily disturbed when moving the fermenter. Stick to the 1/2 teaspoon rule for a standard 5-gallon batch; it is surprisingly potent stuff.
When do I add the gelatin?
Temperature Matters
You can add it any time after fermentation and word on the street that it actually works best when the beer is quite cool. A common timing is to add it a couple of days before you intend to bottle your beer.
Crucial Tip: Cold Crashing. Gelatin is essentially ineffective at room temperature. For it to work its magic, you must chill the beer to below 10°C (50°F), and ideally as close to 0°C (32°F) as possible. This "Cold Crash" encourages chill haze proteins to form, which the gelatin then binds to and precipitates out.
How do I add the gelatin?
Preparation Guide
A good trick is to dissolve it in a half a glass of hot water. You then open up the fermenter or carboy, add the liquid and then shut the fermenter back up.
Detailed Process:
- Boil water and let it cool slightly to around 65°C (150°F). Do not boil the gelatin itself! Boiling denatures the collagen, turning it into useless jelly rather than a fining agent.
- Sprinkle the 1/2 tsp of gelatin onto the surface of the hot water.
- Let it Bloom: Leave it alone for 5 minutes. This "blooming" stage allows the granules to absorb water and expand. If you stir immediately, you'll get clumps.
- Stir gently to dissolve after blooming.
- Pour gently into the fermenter to avoid splashing and oxidation.
Gelatin vs. Irish Moss
Hot Side vs. Cold Side
A common question is: "I used Irish Moss in the boil, do I still need gelatin?"
Yes, they do different things. Irish Moss (or Whirlfloc) is a "Hot Side" fining that works on large protein breaks during the boil. Gelatin is a "Cold Side" fining that works on yeast and chill haze during fermentation.
Think of Irish Moss as the sledgehammer that removes the big debris, and Gelatin as the fine sandpaper that gives you the polished finish. Using both yields the best results.
Do I need to use gelatin if I'm making an ale?
Aesthetics & Flavor
For many people, clarity of beer is important to them. If you are making a dark ale, clarity may not be so important to you.
However, finings do remove leftovers that can impinge on the taste of the beer too. The gelatin helps remove the unneeded proteins and polyphenols from the beer.
These polyphenols (tannins) often cause astringency—that dry, puckering sensation in the mouth. By removing them, gelatin can actually "smooth out" the flavor of a beer, making it taste more mature than it actually is.
Shelf Life Bonus: By dropping these proteins out of suspension early, your beer will also age more gracefully. Proteins are often the first thing to degrade and stale in the bottle, so removing them extends your beer's stability.
Why is my beer still cloudy?
Diagnosing Haze
If you used gelatin and your beer is still hazy, you likely have one of two problems:
- Permanent Haze (Starch): If you didn't convert all the sugars during the mash, you have starch haze. Gelatin cannot fix this. You can test for this with a drop of iodine (if it turns black, it's starch).
- Infection: If the beer is hazy and tastes slightly sour or plastic-like, it's a bacterial infection. No amount of gelatin will clear this.
- Pectin Haze: Common in fruit beers if the fruit was boiled. Pectinase enzyme is needed here, not gelatin.
Kegging vs. Bottling
Different Approaches
For Bottlers: Add the gelatin to your fermenter 2 days before bottling. Do NOT add it to the bottling bucket, as you need time for the sediment to compact so it doesn't end up in your bottles.
For Keggers: You have a choice. You can add it to the fermenter as above (cleaner transfer), OR you can pour the gelatin solution directly into the keg before racking the beer on top. This ensures great mixing. The first pint you pour a few days later will be thick sludge (the gelatin doing its job), but every pint after that will be crystal clear.
Where do I get gelatin from?
Supermarket vs. Homebrew Shop
Most specialist beer shops will stock fining agents such as gelatin. You can also try your local supermarket as it's used in many cooking recipes. You can totally order it online from Amazon for speedy delivery too.
Gelatin can come in powdered form and sheets. Powdered (Knox brand or similar) is generally easier to measure and dissolve for brewing purposes.
Make sure you buy unflavoured gelatin.
If you use Jello because you know it has gelatin in it, you might be in for quite the taste surprise. That said, we've been known to use gelatin jelly beans from time to time...
Vegan Alternatives: Of course, if you don't wish to use gelatin (maybe because you're trying to make vegan beer?), remember that gelatin is an animal product. You can try to use other kinds of finings to clear your beer, such as Biofine Clear (silicic acid) or Irish Moss/Whirlfloc (seaweed derived) which are both excellent vegan-friendly options.