For a while now, I’ve been wanting to have a go at making a simple Oatmeal Stout. The addition of a proportion oats to a stout can significantly add to the smoothness and the texture. It imparts proteins, lipids and gums which increase the viscosity and body and give the stout a lovely silky mouthfeel.
The difficultly is that oats (and flaked barley which is often used) need to be mashed, and with our full-mash equipment still at Fendog Farm, we’ve been reduced to extract and speciality grain brewing for the time being. Although you often see extract recipes for Oatmeal Stout, in reality steeping oats does nothing except realise a starch haze – not necessarily a problem with a stout, but if you want anything good to come out of them, oats need to be mashed.
So I decided to have a go at a partial mash – a mini-mash really. I have a small cool box, insufficient for a full-mash, but big enough to mash the small amount oats and flaked barley to add to an extract brew.
I filled it with water heated to 69 degrees shooting for a mash temperature of about 67 degrees after the grain is added. Then I added the oats and flaked barley tied into a large grain bag, I put the lid on and left it mash for an hour. The liquid was then poured into the boiler and I did a kind of sparge by pouring more water over the grain and again letting it sit for 15 minutes. This liquor was also added to the boiler, topped up to 5 gallons and the speciality grain added in another grain bag to form the pre-boil tea. The rest of the process was the same as a normal extract brew. The full recipe was as follows: