Basic Sanitation

This article is written for beginners about how important correct sanitation is and how to go about it.

Background to Bugs

First of all, a bit of background. Our wort always contains yeast and bacteria. Their aim is to replicate. They do this by using the stored chemical energy in sugar molecules. There are many many thousands of types of bacteria and yeast. Brewer's yeast is used for its ability to produce alcohol. In the process of utilising the sugar, by-products are produced. By-products in beer made by bacteria and wild yeast (ie yeast that are not brewer's yeast) are detected as off-flavours and aromas.

To make sure that no extra unwanted flavours are added to our beer we need to limit the amount of bacteria in our brew to only our selected brewer's yeast. Our brew is a solution of malt which is made from sugars, not table sugar that you put in coffee but still sugars that any self respecting bacteria would just love to eat.

Bacteria multiply very quickly and this means that only one stray bug ending up in your brew can quickly start multiplying, making by-products and spoiling the whole batch. There are bacteria everywhere, floating past your ear, falling out of your hair and settling on the kitchen bench right now. They can hide in nooks and crannies in your fermenter and brew ware. Once you understand how easy it is for a bacteria to slip into your brew and spoil it, so it becomes obvious that maintaining sanitary conditions while brewing is very important.

Under certain light conditions such as afternoon sunlight slanting through curtains, it becomes obvious how much dust is floating in the air. There are bacteria also floating on these dust particles. Once your fermenter is sanitised keep the lid on unless actually transferring ingredients into it. This will help stop the airborne particles and bacteria settling and dropping into your fermenter.

The commercial breweries brew under clean controlled laboratory conditions. The home brewer in a kitchen cannot hope to make a sterile environment to brew in. The best we can do is to clean and sanitise everything that the brew comes into contact with. This includes every nook and cranny in the fermenter, airlock, grommet, tap, threads, o-rings, bottles, caps, ingredients, stirrers, water, thermometers, hydrometers, racking tubes and anything else you brew with. This includes the bench you put the fermenter lid and stirrer on.

Keep it Clean

The easiest way is after using an item, give it a thorough wash with a sponge or cloth to remove any visible gunk, rinse, air dry and store till needed. For the next brew session the item is clean and ready for your favourite sanitising solution. After bottling a batch of beer, wash out your fermenter.

Don't use a scourer on plastic, just an ordinary sponge and some brewer's detergent if necessary. The brown gunk on the inside of your fermenter soon lifts with a bit of rubbing, do not scour as this leaves small microgrooves that bacteria can hide in. Pull the airlock out, the grommet and tap and o-ring if using a screwtop barrel fermenter. Get a clean toothbrush and clean out the threads on the tap, inside the tap, the threads on the fermenter and around every small groove in the lid. Wash everything, rinse and allow to dry and store clean and ready for the next brewing.

Washing out glass carboys is an art. Do not use any hot water. Wash and brush out with a cleaner and rinse with water that is the same temperaure as the room you are working in. They are fragile. They are susceptible to any change in temperature. I broke a glass fermenter while washing. I was washing out on the lawn to provide a nice soft surface. It was very cold with air temp around 8 degC. The grass was wet from water I had tipped out and nice and cold. I rinsed the carboy with warm tap water at around 35 deg C. The bottom of the carboy cracked off due to thermal shock.

If you have forgotten to clean out the fermenter and the scum has set, fill the fermenter to the brim with water, leave for a day and the scum washes off easily. After drinking homebrew rinse the yeast deposit out of the bottles. If there is a yeast residue in the airlock from an enthusiastic yeast, the only thing I found that would shift the deposit is by soaking in neo-pink.

Make sure that any hard to reach surface such as racking tubes, bottling tubes and airlocks are rinsed immediately after use as set scum usually cannot be removed from the internal surfaces. Clean as you go and you will have no problems. Next brew session your equipment will be clean and ready for sanitising. After drinking the contents of a bottle, rinse a few times to get rid of the yeast sediment.

Killing the Bugs

To sanitise a cleaned item, there are basically two options, no-rinse sanitisers and sanitisers that must be rinsed off. I will concentrate on what products are readily available to homebrewers. These products are sodium metabisulphate, bleach, boiling water and neopink. Craftbrewers have a few other products to use such as iodine and TPG. I will not go into the techniques for these products.

Sodium metabisulphate is used in winemaking and is also used by homebrewers. Some brewers consider that it should stay in the winemakers realm as due to the differences in pH and Alcohol level there is far less margin for error in beer making than winemaking.

It is known that sodium metabisulphate in wine causes allergic reactions such as asthma. Sodium metabisulphate forms sulphur dioxide gas when dissolved in water. This gas kills bacteria. After about 24 hours the sulphur dioxide has dissipated and the solution will no longer sanitise. Follow the directions on the packaging or dissolve two teaspoons in a litre of cold water. Coat all brewing equipment in the soluion. Allow 10-15 minutes contact time. Do not rinse off. Swish the solution around in your fermenter so that all surfaces are wet, including all threads. Run some solution through the tap. Discard used solution. Camden tablets are a known weight of sodium metabisulphate and used extensively in wine making. As sodium metabisulphate only inhibits rather than eliminates beer spoiling bacteria, brewers should probably look elsewhere for effective sanitisers.

Bleach is cheap and effective. Use unscented household bleach at about 5ml per litre. Put 100 ml of bleach in your cleaned fermenter. Top up with water and allow to soak for 1/2 an hour. Run some of the solution through the tap. Soak all brewing equipment including fermeter lids, seals, grommets, airlock, stirrer etc in another bucket of this solution. After 1/2 an hour rinse off well with plain tapwater or rinse with boiling water. If you feel that you are wasting bleach, make up a solution of a few litres, swish around in the fermenter, wet all brewing equipment, allow the bleach solution 20 minutes contact time then rinse off. Make sure all bleached equipment is rinsed well otherwise bleach causes nasty off flavours in your brew. Do not soak metals in bleach for longer than necessary. I have found no problem in pickling my fermenter for a few days with 100ml bleach in a full to the brim fermenter. Some plastics are degraded by long term contact with bleach solution. Do not pickle rubber bungs, racking tubes etc for longer than an hour or so. High concentrations of bleach will quickly make pale spots on clothing.

Boiling water can be used to sanitise but will not kill all bacteria. Be careful using it on any glass equipment. Thermometers, hydrometers and glass carboys are very sensitive to thermal shock. Do not use boiling water on these items. Do not use boiling water on airlocks, they turn into useless works of art. For heat to effectively kill all bacteria it needs to be at higher than 100 deg C for more than just a few seconds. To kill 100% of bacteria requires boiling at higher than 100deg C for 20 minutes in an autoclave.

Neo-pink is a widely available cleaner and sanitizer. Dissolve 1 teaspoon per litre in hot water, wash items and rinse in cold water. I have never seen any discussion on the effectiveness of this product or to the required contact time for sanitation. I use it for washing my bottles and find it cheap and effective as the bottles do not need 15 minutes contact time. Some brewshops supply it in bulk if you take an empty container in to be filled. It would appear to not require 15 minutes contact time for sanititation. I cannot verify this but I trust what the manufacturer says on the container. This stuff smells a bit and can cause skin reactions. Use gloves when washing up with it.

Brewshield appears to be the answer to the brewers prayers. This is a no rinse sanitiser that leaves no odour. I use this product in a spray bottle and spray the threads of fermenters, brew areas and use it in airlocks. Many brewers use it and find it successful. It can also be used for bottle rinsing.

Clean Brewing

If your water comes from a municipal supply there will be minimal levels of bacteria in it. If using a tap that is not used often, run the water till the pipe is flushed and then use the water for brewing. However, if your water comes from tanks or bore water, it may have high levels of bacteria and will need treating before using it to rinse with or brew with. It will be fine to drink as a healthy immune system can deal with low levels of most bacteria. Your wort has no immune system and will become infected. The day before brewing activities treat your water by boiling or by camden tablets. If boiling the water, allow the water to boil for 10 minutes before transfering to a clean and sanitised fermenter. Do not store for more than a few days before using this water. Make sure that your wort is properly airated before pitching yeast as boiling removes the dissolved oxygen which yeast needs to work properly. Camden tablets contain a known amount of sodium metabisulphate. Use 5 tablets in a fermenter and allow to stand for 24 hours before using. If you do not allow it to stand for 24 hours the sulphur dioxide formed will kill your yeast. Water added to the boiler in all grain brewing does not need to be treated as the long period of boiling will kill most known bacteria.

Make sure that between sanitising your bottles and getting the brew in and the caps on that you are as quick as possible. While the bottles are sitting on the bench with no caps they are vulnerable to drop ins.

Choice of tap is important. The standard white turn tap that is supplied with most fermenters cannot be pulled apart for thorough cleaning. There is a chance that bacteria can hide in it. It is a good idea to replace these taps with "snap taps" that can be pulled apart and sanitised. After brewing, pull the tap apart and scrub the inside with a toothbrush. Before brewing, soak tap in sanitiser, rinse and assemble. Make sure that your replacement tap takes your bottling device.

Before brewing sanitise your work area by washing down then rinsing with sanitising solution. Also sanitise the following: the can opener, top of tin of malt, scissors that open yeast packet, yeast packet and any scrapers used. Keep the lid on the fermenter unless transferring ingredients into it. Try not to lean over the fermenter as hairs, dandruff etc will drop in. When removing the lid, place it down on a sanitised workbench. Leave the stirring spoon on a sanitised work area or preferably in the fermenter. Wash all bottles out witha bottle brush and sanitise them. Sanitise caps by boiling or soaking in sanitising fluid (not bleach as it is bad for metals.)

When taking hydrometer readings do not float the hydrometer in the fermenter. Use a hydrometer jar filled from the fermenter tap and do not tip this sample back into the fermenter. Drink it or pour it down the sink.

When things go wrong

If you find that your brews are fine for a few weeks and then start turning into gushers with off flavours you have picked up an infection. The infecting bacteria are building up in numbers and are fermenting sugars that the yeast used couldn't ferment out. As the infecting bacteria ferment these sugars excess carbonation occurs with probably off flavours too. Drink these bottle quickly before excess off flavours are generated. You may also bleed the excess pressure to avoid exploding bottles. To bleed bottles, use a bottle opener that has a bar across the bottle cap and levers off a few crimps rather than the type that operates on a single crimp and sharp point near the centre of the cap. Gently ease up a few crimps until the bottle starts to hiss. Watch the foam rise up the neck and ease the crimps back down before foam comes out the top. You will need to do this a few times over a few days to release excess pressure.

If bottles are starting to explode put on leather jacket, gauntlets and full face helmet and take to a safe place and remove lids. There are three grades of overcarbonation, churners, gushers and bombs. A bottle that churns shows excessive carbonation on opening. The yeast sediment starts lifting in chunks off the bottom and foam starts coming out the neck. Gushers spurt out the top, often covering benches and ceilings. Bombs are the homebrewers nightmare of dangerous flying glass, shards of which keep turning up for years afterwards. The absolute highest level is the chain reaction bomb where the explosion of one bottle sets off its neighbours who have also reached dangerous carbonation pressures.

You may talk to brewers and they will boast that they can bottle a batch and put down a kit brew in an hour. There is a 99% chance that in their haste they are neglecting sanitation and suffering infections. Other brewers will claim that it is ok to just rinse bottles without sanitising. There is a great risk of infections gaining a foothold and from then on your brews will be infected as plain rinsing will not kill bacteria. You have invested time and money on brew equipment and ingredients. Spend the extra time on sanitising everything fully to ensure that your beer is not infected.

Infections do not have it all their own way. There are a few more tricks in the brewers bag. Another line of defence against infections besides sanitation is to have active fermentation start quickly. This is achieved by pitching enough of a working yeast into ideal conditions. For kit brewers this means "proofing" your yeast and if it is not working have a backup packet of yeast in the fridge. Proofing means checking that you have a viable yeast. Follow the directions on the packet. Liquid yeast users will use a starter that is firing away. Ideal conditions means that the wort is in the required temperature range and is "airated." Yeasts do not like surprises in temperature. Thermal shock upsets them. The temperature of the yeast should be the same as the wort temperature.

Get the basics of fermentation right before moving onto more advanced brewing techniques. Racking to secondaries, bulk priming in a bottling bucket, using liquid yeasts, partial mashing, full mashing, kegging and lagering will not help your beers if there are infections present.

Happy brewing, Phillipa.