amount of base malt in dry stout

[Dazzbrew]

I want to do a dry stout with a typical 70% uk base malt, 20% flaked barley, 10% roasted barley.
I know the roasted barley can be just steeped, thats no problem, but as a partial mash version how much base malt would need to be mashed with the flaked barley? Would I need an equal amount of base malt & flaked barley? Or half as much? Or quarter etc?
and for how long should it be mashed?

 

[gap]

You will have to mash all of the base malt if it is grain.

 

[Dazzbrew]

Yes but I asked about as a partial mash version meaning;
70% uk base malt + extract, 20% flaked barley, 10% roasted barley.

 

[shacked]

I've been mashing about 3kgs of grain and then using dry malt extract to make up the balance of the required fermentables.

The advice I got was mash as much grain as your equipment will allow and use extract for the rest.

 

[Dazzbrew]

Thats a good way to look at it.

 

[hoppy2B]

Base malts vary in their ability to convert other grains. Encyclopaedia Britannica says you only need 10% malt.

I'd be inclined to mash the roast barley if I did it myself because I think mashing changes the flavour of spec malts. That's just me.

 

[manticle]

Do you mean add the roast to the main mash hoppy? You can't actually mash roast barley.
I think the O P is trying to work out how much base malt will be required to convert the starch in the flaked barley as well as within itself.

 

[hoppy2B]

Yeah Manticle, I meant add the roast to the mash. If you were doing all grain you wouldn't steep it separately. That would just complicate things. I've read that the English would just drop it in the kettle. I don't know what they do nowadays.

I know he's doing a partial so some of the base malt referred to must include extract.

Half as much as the flaked barley should be sufficient.

 

[manticle]

Actually cold steeping dark malts in full mash is not unheard of. I do it myself for beers with large portions of roasts (stouts, porters) as I like the smooth character it brings and it means I don't need to concern myself with the mash being too acidic.

 

[hoppy2B]

Oh ok, that sounds like a good idea actually.

 

[Dazzbrew]

I think the O P is trying to work out how much base malt will be required to convert the starch in the flaked barley as well as within itself.

spot on Manticle.

 

[manticle]

It will depend on the diastatic power of the base malt you choose. Generally, the more highly kilned the less it will have but you should be able to get a Lintner value for your chosen base.
As suggested above though - work out the total capacity of your mashing vessel and work backwards from there.

I'm on a phone so linking is a pain in the arse but if you google 'lintner malt' you will get a number of useful links. The article below the wikipedia one has some good links for partial mashers using adjunct grains.

 

[Dazzbrew]

No worries, thanks