The malt bill
This is a small ale by necessity—no place to hide poor brewing technique! In a big, roasty Russian Imperial Stout we can use a cheaper malt, not here!
So we will choose the best malted brewing barley there is: Maris Otter (called Golden Promise in Scotland where it is grown for making whiskey.
Looking at the Bairds Malts website we get:
Quote:Extract (0.7/0.2mm), dry: 310 LDK min
https://www.bairds-malt.co.uk/the-1823-heritage-collection/maris-otter-finest-al...310 is the “degrees of extract (DE)” we can get from the malt—using laboratory techniques. Brewers can only get like 80% efficiency so .8 x 310 = 248.
We can plug this into the formula for calculating the weight of grain needed to get a specific gravity wort of our desired volume.
We want G to be 1050 max (50 gravity points.) Our V is usually 22L so we can calculate the weight (W) of grain from:
G = (W x DE)/V (so the more grain, the higher DE and lower the volume the heavier the wort)
50 = (W x 248)/22
So W = 50 x 22/248 = 4.435Kg malt
Personally, I would increase the grain bill to 5Kg and stop sparging while the last runnings are still fairly thick—wasting a bit of the sugar but getting a wort full of good flavor with no husky etc off flavors. We are home brewers, the biggest beer I ever brewed was 16Kg of grain, brewed it with a mate we had three mash tuns and 2 kettles going. A commercial brewer uses so much grain they could not “waste” any extract.
There is one more thing we can do to boost the malt flavor—next time.