Franconia Beer Message Board
OT: Specific Gravity vs. % Stammwürze |
| Posted by barry on 2015-09-08 01:23:58 |
| OG is not an absolutely accurate measurement of the percentage of alcohol (or specific gravity) of the final product because this also depends on factors such as the type of yeast used, mashing temperature, composition of the grist, etc. However, it is, generally, a pretty good and easy guide to the potential strength of the beer. According to our friend Frank Baillie, OG can generally be converted to percentage alocohol by simply moving the decimal point: thus, OG of 1037 becomes 3.7% alcohol - generally! According to Frank, in 1974 and the 10 previous years, the average OG of beer in the UK was 1037, which was approximately 3 degrees higher than 20 years ago. I assume that he means 3.7% as against 3.4%. He quotes the following figures for different kinds of beer: Draught bitter 3.0 - 4.5 (I assume that this figure includes keg varieties) Draught mild 2.5 - 3.5 (ditto) Light ale 3.0 - 4.0 (essentialy, bottled bitters, particularly popular in the south when mixed half/half with draught beers) Pale ale 4.0 - 6.5 (presumably, this includes IPA) Brown ale 2.5 - 3.5 (basically, bottled mild ale, particularly popular in the north when mixed half/half with draught beers) Stout 3.5 - 5.0 (perhaps the various strong stouts raise the average) Strong ales and barley wines 6.0 - 10.0 Lager 3.0 - 4.0 (these were generally ersatz lagers brewed by British brewers) Strong lager 6.0 - 8.0 (the only one that I can remember from this time was Carlsberg Special) I think what this indicates is the range of beers available. In his book, Frank lists the products of all the contemporary regional breweries (anyone care to hazard at a guess at their number?), plus the 'big 7' nationals. What is noticeable, in both cases, is the large number of different beer kinds produced by each brewer, including, of course, the ever increasingly ubiquitous keg beers. Grist to the mill in favour of weaker beer? |