Gear questions – Page 3

Most times fermentation is a peaceful process and normally you should only see some bubbles forming in the airlock from the inside and occasionally bursting out. However, airlocks can sometimes overflow during very active and aggressive fermentation and give you a panic attack. If this happened to you for the first time and you weren't prepared, it can make you think that something is wrong or you are about to lose the entire batch of precious homebrew! Why do airlocks overflow? Airlock overflow is common when fermenting heavy beers and when there's inefficient space within the fermenter. Yeast will get aggressive with eating sugars and thus produce high amounts of Co2 which will create a vacuum and push the foam called krausen through the airlock. Can it ruin your batch? Well, unless you do something about it, it indeed might, so do not waste time. What to do when overflowing happens If overflowing just happened to you, do the steps below. I'll also later share a few tips to prevent this from happening again. 1. Clean and sanitize everything If there's lots of krausen over the airlock and down on the fermenter you'll need to clean it with a towel or something first. After that, it's important to sanitize the area around the airlock because if you do not remove the airlock, some gems may find their way in with the liquid around it. Spray that area with a sanitizer and give it a minute before proceeding to the next step. 2. Replace the airlock with foil or tape You'll want to cover the hole with something, so the air doesn't get in. If some air enters it is inevitable, but too much air can ruin the beer. Foil is naturally sanitized when you unroll it, so simply put some over the hole. If you have some similar tape you know isn't dirty you can use it too. 3. Clean, sanitize and return the airlock Wash the airlock with water to remove the foam. Sink the airlock into sanitizer and fill it with liquid of choice before returning it. My favorite liquids are sanitizer/water mixture or vodka. How to avoid airlock krausen overflow? Most homebrewers won't often experience the effect of krausen overflow, however, it can happen due to sufficient space within the fermenter when brewing stronger and more complex beer styles. Therefore, it's good to be prepared for it in advance. Use anti-foaming agents It's possible to counter the foam, so the krausen never has to accumulate to the point where it escapes the fermenter. You can ideally use FermCap (work great) or small drops of olive oil you probably have in the kitchen (however I never used the oil and although it could work I am worried about possible infection). These anti-foaming agents will create a kind of barrier at the surface which will prevent the foaming from forming. Use a bigger fermenter or leave more space on the top Prevention is the best method, so simply leaving more room from the top in the fermenter will allow krausen to raise but never leave the fermenter. I never full the fermenter, so if it has a capacity of 8 gallons I will never go beyond 5 or 6 gallons of wort, especially not with heavier beers that are known to cause more krausen during fermentation. Buy reserve airlocks If you have a second airlock, this can be a good time to replace the old one with it. Airlocks are super cheap, so it's not bad to have a few of them in a box in case you need them. Make a blowout tube If the fermentation continues to be aggressive it's not enough to clean or replace an airlock because overflow will continue to cause problems with time. A blowout tube can save you and the best of it is you can make it on your own if you have a tube, some bottle, or a jar and some tape. I prefer jars or larger vessels because wine bottles are smaller and less stable. Sanitize the tube Fill the jar with sanitizer/water mixture Place one end of the tube into the fermenter through an airlock hole and the other end goes into the jar. Dig the tube a couple of inches in (but do not put it in the contact with the wort). Tape the area around the tube in the fermenter to fix it in place and to make a safe seal With the help of a blowout tube, you will still have a filter for Co2, the air won't get in, and krausen will have enough room within the tube to never cause any danger to the fermentation. Final take on If you have ever experienced krausen overflow, congratulation on a successful fermentation. As you now know it's an indication that your beer is becoming a real deal and it only needs a little intervention from you to put it on a leash. It's always good to be prepared in the advance though!