Last month we went through airlocks not bubbling etc. and this month I thought we could look at the science of brewing.

I’ve had nearly 13 years in the Home Brew business and in that time I’ve heard some great stories of brewing, some are funny and some a little scary. There is a science to brewing and it is a logical science. Logic like the airlock doesn’t have an effect on the ferment, the ingredients do.

This last week a customer in our shop advised me that one stubby of commercial beer in his 22litre brew would make his brew taste like that commercial beer. Some readers may laugh at that but spare a thought for the brew shop staff trying to stay composed. I have a choice, I can nod in agreement at the idea or I can ignore the fact that the customer is always right and point out that 330ml in 22 litres, one part in 66, would not have any effect. I think most customers would prefer to hear the truth but sometimes I wonder.

The customer also had a mate who would brew without yeast. If the brew fermented then something gobbled up sugars. It may have been bacteria, (the water and the air we put in our fermenter is not sterile) or it may have been yeast spores floating around his brew area from previous brews that settled on the surface and did the job. The taste would indicate which. A better option is to use the kit yeast.

The customers reply was that every brew shop told him something different and I am sorry for that. Brew shop staff are not generally formally trained in brewing so they often offer opinions. It is part of the wonder of this science that art also plays a part in design of a beer but the science doesn’t lie it’s logical. Does the advice make sense? Do any of the following “secret” ingredients improve a brew or do they just disguise poor quality ingredients? I swear they have been whispered to me in the shop.

A 2 litre bottle of passion fruit soft drink, lemonade, 500g jars of marmalade, plum jam, apricot jam, vegemite, toast, honey and raisons have all been tried. Some like the raison in a bottle of stout provide the sugar to prime the bottle but a teaspoon of sugar would have been cleaner and a more accurate measure. Rainwater is another problem waiting to happen (one day the roof will be contaminated, birds fly over it). That’s logic and if your brew shop doesn’t provide you with the truth you can waste a lot of time and effort. Forget trial and error, good quality malt, hops, yeast and water make good beer; just ask the successful German brewing industry.