First Brew Advice

[bobos]

Success!

Spent some time on making a copper manifold for my mash tun and cannibalising two Tesco kettles for my boiler and I now have actual booze fermenting! Proper chuffed I am too.

(note to self - make wort chiller and sparge manifold for next time!)

Now... I'm trying to suss out this efficiency malarky. I've been using the calculations from this site

http://www.beersmith.com/blog/2008/10/2 ... r-brewing/

and I think I've got about 55% but I can't find a number that matches the "potential points" on the Maris Otter grain I used

http://www.the-home-brew-shop.co.uk/aca ... rains.html

It mentions these figures "Premium Maris Otter Pale Ale, As Is l°/kg 300, Dry l°/kg 309 EBC 4.5" but I can't relate that back so have used a generic figure of 1.036

Any help on where to look for the elusive 1.??? value or how to convert from what is stated on the Home Brew Shop web site would be appreciated

[coatesg]

Maris Otter gives roughly 300 points total per kilo used (in fact most pale/lager malts do).

So, as an example, if I brew 23L (measured in the fermenter) of 1.036 beer with 4kg of Maris Otter only, my calculations would go as follows:

4kg x 300 l°/kg = 1200 l° - this is effectively the theoretical maximum points in the brew - you will never hit this!
36 points * 23L = 828 points total in the fermenter

To find the overall brewhouse efficiency (ie how much in the fermenter versus theoretical maximum), you divide actual by theoretical:

828/1200 = 69%.

The difference between this figure and what is usually called "mash efficiency" (which usually includes losses to sugars left in the mash) is the wastage in the boiler (to hops, deadspace, etc). My figures tend to come in around 77% fairly repeatedly for the mash/sparge efficiency, which is what I tend to work off as that allows you to get the bittering calculations at least repeatable. The losses in the boiler vary according to recipe, so it's harder to be consistent with the calcs.

Otherwise, don't get too hung up on it - the difference between 65% and 75% efficiency really isn't that much - a few hundred grams of malt in this case - probably about 50p.