BREWING BEER

FERMENTING

There is virtually no difference to the fermenting process between kit beers and all grain beers. Perhaps the yeast supplied with kits is not the same and I have noticed that fermenting of all grain seems to take longer. I don't know if this is due to differences in sugar structures, the yeast strains or the lower temperatures I ferment at. It is probably a combination of all of them.

In his books Dave Line used to recommend acquiring cloudy pints of beer of the type being copied from a bar or pub and then propagating yeast from the beer, for use in Home Brewing. Failing this he recommended propagating the yeast from a bottle of Guinness. I have seen similar advice in later books by other authors. This is not easy to do in Singapore, since potential sources of cloudy pints are limited, and the yeasts used by commercial brewers would die at Singapore air temperatures.

I have been using dried SAF S-23 lager yeast for my pilsner and have been perfectly happy with the results. In the section on preparing the wort, I discussed starting the yeast first. When I lived in the UK, I used to start the yeast in a solution of water, sugar and mineral additives, which were sold in home brew shops specifically for yeast propagation. At the time of writing I have not found these minerals available in Singapore. The reason I now use wild organic honey for this purpose, instead of sugar, is because I imagine it would contain more minerals than refined white sugar would. In any event honey works fine.

Fermenting Bin, Hydrometer and Digital Thermometer

When brewing a bitter at 20°C, then reading the hydrometer is very straight forward. If brewing at higher or lower temperatures then gravity needs to be adjusted upwards or downwards. My hydrometer was calibrated at 20°C and the instructions provide the following adjustment table:-

10°C	-0.002
15°C	-0.001
20°C	NONE
25°C	+0.001
30°C	+0.003
35°C	+0.004

So if I am fermenting lager at 10°C and I take a reading of 1040, I need to adjust this to 1038. If the liquid is still fermenting then bubbles and/or sediment in it, can disturb the results, so it is usually best to let the liquid stand for a while before taking the reading. I usually run off about 150ml into a glass and drink about half of it (there has to be some enjoyment in taking hydrometer readings) and let the remainder stand. Then when the sediment and bubbles have settled out, I transfer it into the hydrometer tube and take the reading. The hydrometer and tube should be clean and dry, since any water present will reduce the gravity.

I usually keep fermenting until there are almost no more bubbles in the liquid I draw off. At this stage there is a lot of yeast sediment in the bottom of the fermenting bin, which I don't want to transfer into the bottles. I draw off most of the beer (leaving behind the sediment) into a large sterilised plastic bin and put the lid on. I then wash out the fermenting bin and return the brew to it and put it back in the fridge. By day two or three after this, the bubbles have stopped completely, and a bit more sediment has fallen out of solution, but not enough to interfere with bottling. By this stage the Gravity has dropped to 1010 or below.

On one occasion the gravity read 1012, and there were still some bubbles. Because I was going away for an extended period, I decided to bottle anyway, but with a reduced amount of priming sugar. I ended up with a batch of beer which gushed. It gushed so much that by the time it had finished gushing, all there was to drink was yeast sediment. I ended up emptying all the bottles into a sterilised plastic bin and rebottling the whole lot. So my advice is don't bottle until all the evidence points to primary fermentation having completely finished.

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