FAQs
We’ve put together some of the questions home brewers most frequently ask our master brewers - and the answers!
- Why is my new batch of beer darker than my last batch even though I used the same kit?
- Why is my brew taking so long to ferment?
- Why is my beer flat?
- Why does the head on my beer disappear as soon as I pour it?
- Why does my beer gush all over the place when I open the bottle?
- What is the best brewing sugar to use?
- How do I know if my water is ok to brew with?
- My brew is not fermenting at all, what is wrong?
- How do I use my hydrometer?
- How do I ensure that my brew does not get infected?
- How can I adjust the alcohol content of my beer?
Q: Why is my new batch of beer darker than my last batch even though I used the same kit?
A: When manufactured, each type of malt extract eg lager, draught etc meets a specific specification for colour but as time goes by the extract will naturally darken especially if kept at elevated temperatures. So the variation in beer colour is due to the different ages of the malt extract in the homebrew kit. Each can has a best before date printed on the base which is two years after the date of manufacture so this will give you an indication of how old the kit is when you buy it. If you buy a number of kits at once be sure that you store them in a cool place. You may even like to place the yeast sachets in the fridge as that will keep the yeast fresher for longer.
Q: Why is my brew taking so long to ferment?
A: The most common cause of slow fermentation is lower than recommended fermentation temperature. It is important to keep your brew above the minimum recommended temperature especially in winter; you can use a heating pad or hotbox to help keep the temperature up. If the brew becomes infected that can also cause a slow fermentation. If you notice a sour or off smell and a white film on the surface of the brew then you may have an infected brew.
Q: Why is my beer flat?
A: There are a few possibilities, first check that the bottles have been stored above 18°C for at least a week. If not move them to a warmer place and wait another week to see if that improves things, but be careful not to let the bottles get too hot as that could kill off the yeast. Other possible causes include:
- Too little sugar added to the bottles.
- Leaving the brew in the fermenter too long after the completion of fermentation.
- Not enough yeast in the bottle due to filtering or excessive use of finings.
- Faulty crown seals.
Q: Why does the head on my beer disappear as soon as I pour it?
A: Most likely cause is dirty glassware especially fat residues and detergent residues, (this includes both drinking glasses and bottles). Make sure you rinse your glassware and everything that comes into contact with your brew thoroughly.
Q: Why does my beer gush all over the place when I open the bottle?
A: Most common cause is bottling the beer before it has finished fermenting. You need to check that the gravity is constant for 2 days in a row before you bottle. In some cases the gas level may even build up so high that the bottles may explode so you really do need to be careful. Also check correct amount of sugar is added per bottle. If the brew is infected then it may also cause the beer to gush, look out for a ring of scum around the top of the bottle as this often indicates an infected brew. Don't store the bottles in a hot place and refrigerate the beer for 24 hrs before opening.
Q: What is the best brewing sugar to use?
A: The best brewing sugar to use is a Glucose based sugar, these come in many forms. We would recommend a liquid brewing sugar or a Dextrose based sugar. An alternative to these is to use a malt extract, we advise using the same quantity of extract as you would sugar.
Q: How do I know if my water is ok to brew with?
A: If your water supply is ok to drink then it should be ok to brew with. If your water smells or tastes strongly of chlorine (bleach) then boiling it first will make the water better to brew with. If you do boil the water then you will need to add oxygen back into the water as boiling drives off all oxygen and you need oxygen in the wort to make good beer. Stirring the wort vigorously for a few minutes will help introduce oxygen.
Q: My brew is not fermenting at all, what is wrong?
A: The only way to be sure that the brew is not fermenting is to check the gravity using a hydrometer, the airlock activity is not an accurate enough indication. If the gravity has not changed from the starting gravity then your brew is not fermenting, at this stage you can add another sachet of yeast and stir the brew thoroughly with a sterilized spoon.
You need to ensure that you don't add the yeast to your brew until it is the correct temperature because if it is too high then you can kill the yeast. Also if it is too low then the yeast will fail to activate and you will need to warm the brew up and give it a stir to get the yeast going.
Q: How do I use my hydrometer?
A: Remove airlock from lid and fill sample jar with beer from the tap, replace airlock. Put the hydrometer into jar and spin it to remove any air bubbles. Blow gently on top of the beer to remove any foam then read number on the hydrometer which lines up with the top of the beer. Rinse the hydrometer in water and discard the beer - do not add it back to the fermenter as this could infect the brew. If you wish to check that your hydrometer reading is correct you can check it in water at 20 degrees, it should read 1000
Q: How do I ensure that my brew does not get infected?
A: To avoid infection you need to be very diligent when it comes to cleaning and sterilizing. Always use the recommended concentration and method and remove the tap from your fermenter every now and again to make sure it is getting cleaned properly. Some things to be careful of include:
- Be careful when cleaning your fermenter that you don't scratch the plastic as it will create a breeding ground for bacteria.
- Don't use scouring pads or other harsh brushes.
- Add the yeast to your wort as soon as possible so alter the amount of hot and cold water you use when making up the brew so that the temperature is right first off and you don't need to wait.
- Bottle the beer as soon as it has stopped fermenting but make sure that it has stopped fermenting before you bottle.
- Insufficient temperature control.
- Avoid opening the lid of the fermenter so that you don't introduce air.
Washing bottles
You need to make sure that the bottles you use have been thoroughly cleaned and sterilized before you use them - this will minimize the risk of infected beer. Wash your bottles in warm water and bottlewash then rinse with a sterilizing agent like sodium metabisulphite.
Q: How can I adjust the alcohol content of my beer?
A: If desired you can reduce the alcohol content of your beer by reducing the amount of sugar you add into the fermenter. The following is a rough guide of the approximate % alcohol with varying amounts of sugar
| Kgs of Malt Extract | 250 gms Sugar | 500gms Sugar | 750 gms Sugar | 1000 gms Sugar |
| 1.7 | 2.8 | 3.3 | 3.9 | 4.4 |
| 1.6 | 2.6 | 3.2 | 3.7 | 4.2 |
| 1.5 | 2.5 | 3.0 | 3.5 | 4.1 |
