What should be done differently for high-gravity beers?

Question

What, if anything, should you do differently when brewing a high-gravity beer?

Answer 1

First, make an appropriately sized starter! Pitching a regular old vial into something like a 1.090 beer is a good way to overstress the yeast and get lots of undesirable esters, and have a beer that didn't finish out completely. Jamil has a helpful writeup on pitching rates and a pitching rate calculator that will help you size a starter.

Second, pick a yeast that is known to handle the higher alcohol.

Third, make sure your aeration step is solid. Your beer will need to be well aerated to ferment out completely.

Answer 2

I'd add to be sure you can maintain a proper fermentation temp, also. High gravity beers have a propensity for throwing fusels, and if you don't keep the temp down it can exacerbate that.

Answer 3

By following these steps, you should be able to approach 20% ABV:

• As Morgan said, make sure you use enough yeast!
• Aerate the beer with pure oxygen at the start of each fermentation phase
• Add sugars and yeast during secondary (and/or tertiary) fermentation
• Use different yeasts for the different fermentation phases. Yeasts that have high alcohol tolerance don't necessarily like high gravity, and vice versa — start with a yeast that can take high gravity, finish it off with one with high alcohol tolerance.