First off, you'll notice that I calculated this Barleywine at 52% brewhouse efficiency. The first time I brewed this recipe, I calculated it at 60% (I had never attempted anything like this before), but only got 52%. If you're using a cooler mash tun, you're going to want to pick up another cooler and split the mash between the two. If you do so, recalculate your efficiency accordingly.
Don't go with the standard 1.5 qt/lb water/grain ratio with this one. This is meant to be a chewy beer, so we're gonna go with 1 qt/lb in the mash. We'll do a full hour at 144°F to make sure the beta-amylase is happy. Still want some palatable malty sweetness, so raise it up to 158°F for 25 minutes and let the alpha enzymes do their thing. Mash out at 168°F.
Don't rush any of the processes or cut back on any expenses when you brew this beer. If you're going to attempt something like this, go hard or go home. Water chemistry, pH stabilizers, yeast nutrient, etc.; she deserves it all!
Note the 2-hour boil time.
The best way to ferment this is by collecting the yeast from a previous batch. You'll have a significantly higher cell count.
If this is your first time brewing this, you'll want to make two 2 Liter starters with the White Labs WLP099 Super High Gravity Ale Yeast. It's an English Ale that has fruity notes that shine through better at higher gravity points, so have fun with it.
Pro-Tip: Make your second starter out of the boiling wort and dilute it down to 1.040 SG. It'll make the starter environment closer to the one you're pitching into
Pitch the first starter slurry at 65°F after you aerate the crap out of the wort. For you carboy-shakers, that means 5 minutes of vigorous shaking. If you're worried about over-oxygenating your wort (which is pretty hard to do with a brew of this size), use the olive oil method by dipping the tip of a sanitized sewing pin into olive oil and stirring it into the chilled wort.
After 48 hours, hit this bad boy with another dose of oxygen to ensure maximum yeast reproduction and full attenuation (if you used the olive oil method, skip that step), then immediately pitch the second starter slurry (still at 65°F).
Note: It's important to yell "SEND IN THE CALVARY!!!" when you pitch your second starter
After primary fermentation starts to slow down a bit, melt 4 lbs of dextrose down into a simple syrup/caramel (DON'T BURN IT!), then pitch directly into the fermenter. You don't want to use too much water to make the syrup. Don't add the sugar at flame-out (like many recipes call for), because you want the yeast to chew through the maltose first, then let it get to the simple sugars. If you pitch the yeast after the dextrose, it will chew through the simple sugars first, and then be too tired to get through all of the maltose.
Primary fermentation at 65°F for 3-5 weeks. In the old days, the English Barleywine brewers would roll the barrels around the courtyard after primary fermentation to rouse the yeast. I like to go by tradition, so shaking the carboy at around the 4 week mark should do the trick. DO NOT SKIP THIS STEP! After rousing the yeast on my first batch, I saw a significant increase in activity over the next few days. Once you're sure primary activity is done, go ahead and move onto secondary fermentation. Make sure you save that yeast for another batch!
Secondary fermentation at at 68-69°F for 2-6 months (use a CO2 blanket if you want to be safe)
If you're bottling, use a priming solution made of 3.5 oz of priming sugar for a 5 gallon batch. Pitch this solution along with another 1/2 package of WLP099.
Give this beer a few months to condition before preliminary tasting. Don't babysit; let the yeast do the work for you. Trust me, you'll reap the rewards in the end.
Save a few bottles by cellaring at 55°F (lay the bottles on the side). Try to plan it out so that you open one bottle each year for the next 10 years, and watch the flavors develop. Save them for a special occasion (birthday, anniversary, your biannual air filter changing, etc.)
Happy Brewing and Cheers!