Is it true that in a pilsner lager all of the sugar turns to alcohol? my mum reckons it is?

Question

Is it true that in a pilsner lager all of the sugar turns to alcohol? my mum reckons it is?

Answer 1

The residual sugars in any brewing process are a function of three things: the time allowed to brew, the amount of starting sugar, and the capacity of the yeast to withstand alcohol.

The longer you allow a brewing beverage to ferment, the more all of the sugars made will turn into alcohol. As long as there is still sugar in the wort, more will be consumed by the yeast and turned into CO2 and ethanol.

The second two work together. Given enough time, and a hardy enough yeast, all starting sugars in any normal style would be converted into alcohol. However, if the yeast is not hardy enough (no strain can go reliably into the high 20's for alcohol by volume) the yeast will stop converting sugars into ethanol and CO2 faster than a counter-reaction and the death of the yeast can reduce it. The brew will be in equilibrium. It is at this point you can determine how much sugar remains.

If the starting amount of sugar would only allow the beer to go to 4% abv, but you put in yeast hearty enough to go up to 7, the beer will have only a negligible amount of sugars remaining. Any American lagers, including all of the major brands of pilsner (budweiser, coors, miller) are brewed in this fashion. Only a small amount of any sugars remains.

Other brews, such as a single bock, or even some dopplebocks may have some sugar remaining. Some stouts and porters (oatmeal especially) are exceptionally sweet to start, which is a large part of the reason why they are toasted prior to fermenting: so the remaining sugars are balanced with the 'coffee' flavor of the toasted grains.

As a rule, most pilsners, by style, tend to have only negligible amounts of sugar in them.

Answer 2

The main difference with Pilsner vs British ales is that Pilsner uses a different kind of yeast that is a bottom fermenting yeast vs the top fermenting yeast of English beers.    It has nothing to do with the sugar content.

Answer 3

The sugar in beer is called maltose, and it's not specifically sweet as it's a by product of the grains used in the brewing process. Almost all of it is converted to alcohol as part of the brewing process. Lighter-colored beers, like pilsners, have less from the start which leads to their light color, taste and alcohol levels.

I believe that there are always some trace amounts of simple sugar left in all beer after the brewing process, but the lighter beers especially have a negligible amount.