Comments on: Make Biofuel From Your Home Using Leftover Beer

By: Amanda

Amanda — Tue, 10 Feb 2009 14:57:31 +0000

I know all to well of a great source of “leftover beer.” When bartending I’d estimate that I pour one sixth to one quarter of beer down the drain (depending on if the keg has been properly transported and cooled), in order to get a small head on a glass or pitcher. This waste runs right into the sewage where is is unrecoverable. Sounds like every restaurant, bar or club should get their hands on one of these machines and as we should all do with all waste streams, separate, recover, and use it to fuel something else. Waste=Food.

By: Shane Myers

Shane Myers — Sat, 07 Feb 2009 11:46:18 +0000

I can try, I am not a pro either but have been homebrewing for about 14 years. B
Basically when beer is brewed there are two distinct stages. The first requires work by the brewer, the second requires work by the yeast. Very simply speaking in the first stage the brewer mixes grains (usually barley, but can also be wheat, corn , rice, etc) with hot water to extract sugars. These sugars are rinsed from the grains which are then often sold to hog or cattle farms for feed, and the sugar solution, now called “wort” is boiled with hops, and maybe spices, additional sugars, etc. After the boil the liquid is strained and hops are discarded. The wort is then cooled and mixed with yeast, and begins to ferment. The wort is now beer. The fermentation process creates a number of by products like alcohol (good) CO2 (good) and lots more yeast cells (good and bad) and excess proteins, hop particles and minute specks of grain dust settle to the bottom of the fermenter (generally bad). All of this sludge at the bottom of the tank is referred to as “trub” (pronounced troob). The trub is of course mixed with some of the beer at the bottom of the tank, making a thick mess that smells vaguely of beer and strongly of yeast. Professional brewers strive to get as much beer as possible out of the trub for economic reasons, and for visual clarity of the beer via filtering, thus capturing even more of the biomass byproduct. Homebrews generally don’t worry about filtering, and simply wait for most of the trub to settle.
Hope that helps- I wouldn’t mind being able to turn my homebrew by products into fuel, now they just go in the compost pile. Cheers! Shane

By: Ashwin

Ashwin — Sat, 07 Feb 2009 03:38:28 +0000

To clarify, the company’s claim is that alcohol can be used on a household level to create ethanol in these “microrefineries.” The term “leftover” beer was used to make a point–that one can use bottles of beer to produce ethanol at home; but, I was also told the sludge at the bottom of barrel brews can also be considered “leftover” beer. I’m not a professional beermaker, but this is what I was told it was considered as. Brewer1056, can you help clarify this?

By: Brewer1056

Brewer1056 — Fri, 06 Feb 2009 20:14:12 +0000

Cool idea to use the bottom of the barrel trub and sludge, but what is “leftover beer”? Does not compute…

By: Beer man

Beer man — Fri, 06 Feb 2009 18:15:51 +0000

Photos! I want photos!