Converting AG Recipe to Extract

[mshergold]

I've spotted a recipe for RCH Pitchfork in Norms Real Ale Almanac in the AG recipe section. I seem to remember it being quite a nice beer, but am at the moment only brewing extract beers. Now, the recipe only calls for Marris Otter (4900 grammes). Does anyone know how I convert the recipe for extract? Is it an exact science or is it a more 'suck it and see' kind of thing? I've got Graham Wheelers book and I suppose I could maybe see If I can work out an equation from the recipes that can be brewed both as AG and extract, but my maths is really bad Any help/suggestions would be gratefully appreciated.

[PureGuiness]

I think for malt extract syrup it's about 75%.

Have you got The Beer Engine at all? You can poke in some figures for both grain and extract so see what values give the same OG. Much easier than trying to work it out.

[PureGuiness]

My calculations would be:

Dried Xtra Pale malt Extract (EBC 5.5): 3180
or
Malt Extract Syrup - Pale (EBC 5.5) : 3700

[mshergold]

Thanks guys!