How (not) to brew a Russian Imperial Stout

So when is an Imperial Stout not an Imperial Stout? When it comes out at 5.8% ABV!

Here's our brew day, complete with a description of a couple of process errors that stopped us reaching the 8% ABV target. Anybody else had these same issues?

https://youtu.be/rLKthY4yLXY

I did an Imperial Stout last month. We had figured between 8.5% and 9.5% ABV depending on efficiency. It came out at 7.2% ABV.

Our first problem was we figured our mash at the normal water to grain ratio, only to find out that didn't all fit in the kettle. We waited 15min and drained off a couple gallons so we could fit the rest of the grain in. We tested the drained off portion with iodine and it looked like it was converted, but neither of us are experienced with iodine so we could be wrong. When we added the sparge water, it overflowed again!

When the mash and sparge were over, we added that wort back in and started the boil. Unfortunately, every time it came to a boil, it would boil over, even with the heating element turned down as low as it goes, so we had to keep our hand on the plug from then on.

We finally got it settled to a gentle boil but as soon as we added the hops, it exploded again so then one of us had to keep a hand on the hop spider and pull it out when it started looking stormy.

We still ended up with 10 gallons of wort, just a lousy SG.

Well 7.2% ABV is better than we did, even with all those challenges you faced of water/grain ratio, boil overs etc. How did it taste?

It tastes great! We had a pound of lactose and fermented with S-04 so it still has the body of an Imperial Stout. Then I 'dry-hopped' mine with 12oz of fresh ground coffee. The first couple of weeks it had that tangyness you get from some coffees. Now it is more mellow and blended. It is great to see it transform day-to-day but I doubt it will last long enough to see what real aging does to it.