Making high gravity wort from only malted grains requires either an extended boil, more grain in the mash tun, or both. Due to limitations on equipment size, you may not be able to produce a full-sized batch of a very high gravity brew. In that case, either you’ll need to perform two (or more) brew sessions to fill your fermenter or you’ll need to accept the lower batch volume.
Of course, we all know there’s an easy way to hit any OG you want, with minimal fuss — add malt extract. In this article, I’ll discuss wort production using malt extract.
Malt Extract to Supplement a Full Mash
If you’re essentially an all-grain brewer, but prefer to use malt extract to hit higher OGs — as opposed to boiling your wort longer or adding more grain — here are a couple considerations. You could add an amount of grain to your mash tun such that, fully sparged, you yielded an amount of wort that you could boil down to 5.0 gallons (19 L) in 60 to 90 minutes, or whatever your normal boil length is. On my system, 10 lbs. (4.5 kg) of grain would yield 6.5 gallons (25 L) of wort, and I could boil this down to 5.0 gallons (19 L) in an hour. Having collected enough wort for a 60-minute (or 90-minute) full wort boil, you could simply add malt extract such that you will hit your target OG. In my example, I would need to add 4 lb. 6 oz. (2.0 kg) of dried malt extract.
This would work, but keep in mind that malt is cheaper than malt extract. Currently, on a per gravity point basis, malt extract costs about twice as much as a comparable malted grain. To increase wort gravity in my example above, I’d be better off adding malt to my mash tun than malt extract to my kettle. (At some point, undersparging of the malt would make the costs even, but initially there is a cost difference.) In addition, I suspect the cost of propane required to condense the wort, and therefore gain a few gravity points, would be less than the cost of gaining them by adding malt extract.
So, if you’re an all-grain brewer, a good compromise might be to add enough grain to your mash tun to yield a wort volume that requires a somewhat extended boil. The grain amount should also be a little more than would be fully sparged. In other words, you should leave a little sugar behind in the mash tun (and preferably use it for a side project). Then, make up the difference with malt extract. At a homebrew scale, the difference in cost is likely fairly small, but it’s worth thinking about.
Malt Extract Based Wort Production
If you’re an extract brewer, you will make your wort either by steeping grains or performing a small partial mash and then adding malt extract to reach your target OG. For exatrct brewers, there’s not much new to learn about making a very big beer. Realize, though, that following the modern “rules” of extract wort production will benefit you more when making a ver big beer.
First of all, boil as much wort as possible. Big beers are frequently heavily hopped and the less you dilute the wort after the boil to reach your batch size, the better off you’ll be. Also, the lower the specific gravity in your brewpot, the less your wort will darken during the boil and the better your hop utilization will be.
Secondly, add some of your malt extract late in the boil. The idea behind late extract additions is to minimize wort darkening that results from boiling a thick wort and to increase hop utilization. The first of these is important in any big beer and the second is important for any big, hoppy beer. For a very big beer, you could initially add enough malt extract to make a fairly weak wort (SG 1.032–1.040), then stir in the rest of the malt extract late in the boil.
If you dissolve the late addition of malt extract first in hot wort, it will be easier to work with and won’t sink to the bottom of the brewpot and scorch as easily. To do this, add malt extract to a small pot until it fills about a quarter of the volume of the pot. Then scoop wort from your brewpot into the smaller pot and stir. Once the pot is about two-thirds full and the extract is dissolved, stir the extract into your brewpot. Repeat until you’ve added all your malt extract.
If you’ve ever tried to pour dried malt extract into a steaming brewpot, you know the extract absorbs the steam to form a hard shell on the exposed extract. The extract forms little balls with dry interiors and they need to be broken up. (A similar thing happens with liquid malt extract, although to a lesser extent so it’s harder to see.) Dissolving the malt extract in a separate pot makes it a little easier to work with as there’s less steam involved. (Stirring the extract into the liquid in the smaller pot might also help.) An added benefit of doing it this way is you can keep the boil going as you add the extract. No need to turn off the burner if you stir reasonably well.
Finally, when making a very strong beer using mostly malt extract, realize that the mineral content of your beer is going to be fairly high. All the minerals from the moderate-strength wort that was condensed to make your malt extract will be in your high-gravity wort. Unless you have a good reason for doing so, limit the amount of minerals (gypsum, etc.) you add to your brewpot and try to use soft water, if possible. If you live somewhere with extremely hard water, “cutting” it with a bit of distilled or RO will help. There’s nothing you can do about this and it isn’t likely to have any large, negative effects; just keep it in mind if the recipe calls for a large addition of gypsum (or some other mineral or mineral blend).
Wort production for very big beers can test the limits of your equipment and make the brewday longer. Using malt extract to reach your OG eliminates those concerns, but increases your ingredient cost for the batch. However, it’s always good to have options. Once you’ve got your wort made, you’ve still got a long way to go to turn it into decent beer. but that’s a topic for another day.