Bottling Day Part 2: Bottle Sanitizing

Sanitizer Spray Bottle Ready

Sanitizing

To start with sanitizing and cleaning are two different processes or steps in the beer bottling or packaging process that should not be confused. Cleaning is the process of removing dirt and particles from your bottle whereas sanitizing is the process of killing as many bacteria and fungus as possible after cleaning and before you start filling with your beer. It stands to reason then that you want to kill as many of these critters as possible in order to avoid getting an "infection" in your bottled or packaged beer. The danger of poor or no sanitation is a build up of too many bacteria or fungi in your bottles which will feed off your beer faster than the residual yeast (yeast is a fungi and wild yeast is a wild fungi!). This will result in off flavored beer at best and over carbonated beer and/or bottle bombs at worst, and If you've ever had a beer bottle rupture you'll know exactly how bad it is trying to clean up the sticky mess it leaves behind!

Sanitizer Types

Now before we get into good sanitation practices it would be good to first look at the different types of sanitizers that are commonly used in either home brewing or commercial brewing. For home brewers you will probably only come across four main types of sanitizers and some of you may only ever use one or two of these at best, but its good to know all of the options out there in case you run out of one and need to get something on the fly!

1. Acid Based Sanitizers: Acid based sanitizers are probably the most commonly used type for home brewers and the premiere product in this category is called "Star San", although it has been copied by others and can be found in a number of products ending in "san". This product is an acid based sanitizer with phosphoric acid at roughly 10% as its main ingredient and It also has a number of other ingredients which aid in its effectiveness. Acid based sanitizers are very effective at killing a very high percentage of bacteria and fungi at even small dilutions and they are are also suitable for a range of materials including PET and HDPE plastics which are common in home brewing bottles and fermenters. This type of sanitizer probably makes up almost 70% of the home brew market.
2. Chlorine Based Sanitizers: While not as commonly used as acid based sanitizers there are some brands of chlorine based sanitizers on the market. Where i live there is a company that offers a product called PSR (Pink Stain Remover) which is made up of Chlorinated Tri-Sodium Phosphate. This product is a disinfectant and bleach all in one which is very effective at sanitizing. However these products have one big downside for home brewing or any brewing for that matter, and that's the fact that it contains chlorine so anything that comes into contact with it needs to be washed thoroughly to avoid chlorophenols which are compounds that produce off flavor in beer. Chlorine should be avoided in brewing at all costs and i always recommend that people remove the chlorine and chloramine from their drinking water so in that case i would not recommend this type of sanitizer for the fact that in introduces chlorine to your bottles and fermenters. The other main chlorine based sanitizer is plain bleach which you probably have in your laundry or kitchen already. Bleach can be very handy for treating containers that have had persistent infections, but for a regular sanitizer is just too risky to use and it requires a very thorough rinse afterwards which will get very tedious when your using it batch after batch.
3. Iodine: Iodine is the most common type of sanitizer that you will find used in most hospitals. It's a very effective sanitizer and I've used it myself with no issues in the past. It's less risky than chlorine based sanitizers but i have read conflicting information on whether or not you need to rinse  thoroughly after using it. Some people will claim that if you don't rinse thoroughly you will get off flavors in your beers whilst I've also heard others say that rinsing is not necessary unless you use it in very high dilutions. I have personally used it as a no rinse sanitizer in a dilution that was recommended by a professional brewer and it works for me, but i did switch over to a star san copy as it is also a good yeast nutrient and it has zero risk of causing off flavors in your beer. Better safe than sorry! The most common preparation of Iodine you will find is called Iodophor and its safe to use of all surfaces in a brewery.
4. Heat: The last common sanitizer that i will mention is actually heat and this heat can come in the form of either hot water or hot air/steam. The two most common ways of utilizing heat in home brewing is by either heating glass bottles in an oven at 75c or above  for at least 10 minutes or by filling them with hot water that's above 75c for at least 10 minutes. Heat is very effective at killing bacteria and fungi as long as its hot enough for long enough and the hotter the water or air the shorter the contact time needed for it to be effective. The big plus for heat is that water is very cheap and with an electric kettle a home brewer can easily boil water for the job. The big downside for using heat though is that you are limited to either stainless steel or glass so its very effective for stainless fermenters and kegs and glass bottles. I use this method myself by filling my glass bottles to the brim with 90c water, my bottles stay above 75c for over an hour and after this i spray a bit of star san in them for some insurance but if you go straight to filling them then you should be ok without it, be warned though that very hot bottles are probably not a good home for yeast if your planning to bottle condition. You don't want to accidentally pasteurize your yeast in the process!

Sanitizing Practices

Now you've chosen the right sanitizer the next step is to use it effectively so that you can guarantee that your giving your beer the best opportunity to thrive.

The first thing to make sure of is that you dilute your sanitizer correctly according to the manufacturers instructions. With Star San for example the dilution rate is only 1.5ml/L of water so accuracy with small amounts like that is important! Luckily they have measurements on the container to help you along but if you buy a generic container of Iodophor for example you may have to measure it yourself.

Once you have sorted out your preferred sanitizer you now need to use it effectively which means at the right and and for the right amount of time. The right time to sanitize is generally right before your are going to either ferment or package your beer, and the right amount is enough to do the job completely to avoid infections. 

With your fermenter you want to make sure you have used an adequate amount of sanitizer for the size of your vessel and that it has come into contact with the entire inside surface of your vessel. Once you've poured in your wort from your kettle its too late to go back so make sure you get this right! Generally for a 25-35L fermenter about 4 litres of sanitizer should be enough and if you use a foaming type like Star-San, the foam will help you coat all of the inside surface and I give my fermenter at least 20 minutes with sanitizer in it and i make sure i swirl it around several times during that 20 minutes. 

Sanitizing Beer Bottles

With beer bottles or kegs you want to sanitize right before you fill. With kegs you can make up a full 19L batch of sanitizer and use an old keg as your storage container and it should last you quite a few kegs fills before the sanitizer loses its effectiveness. With bottles a simple spray bottle will do the trick and around 8-10 good squirts into each bottle followed by a good swirl and 10 minutes to sit will be enough. I've been using a $2 1 litre spray bottle to sanitize all of my beer bottles before filling and it has worked very well.

Now whatever you are sanitizing always make sure that once you have fill your vessel or bottle or keg with sanitizer, you seal it or put it in a sealed container for glass bottles, to make sure that nothing gets into your vessel while its waiting to be filled. 

And lastly you can recycle Iodophor and Star-San so make sure you don't tip them down the sink or you're wasting money! Your fermenting vessels should be spotlessly cleaned anyway so the sanitizer shouldn't pick up any dirt and particles and can be used many times before it loses it's effectiveness.

A Last Word

Sanitizing is one of the most important steps in brewing! Get it right and you should have very few problems with infections in any of your brews, but good sanitation is only as good as your cleaning. Remember to always rinse everything out immediately after its used and wash dirty vessels, bottles and kegs thoroughly. Sanitation and cleaning go hand in hand and are equally important in your home brewery.

Happy Brewing!