Beeston's caramalt and crystal malts are all produced from green two-row malt using the following method: The surface moisture is dried off at about 122 °F (50 °C) for approximately five minutes. The malt is then stewed at approximately 149-167 °F (65-75 °C) for about 40 minutes to stimulate the conversion of starches to sugars (crystallization). Drying and curing then takes place at about 176 °F (80 °C) for another 40 minutes, depending on the color required. The final drying and curing temperature varies among products; curing is typically done at about 275 °F (135 °C) for approximately two hours, depending on the color required. The darker the colors, the more intense the flavor.When they say the malt is 'stewed' there isn't any stew like you would see cooking in the kitchen. Instead the malt is being 'baked' and the stewing process goes on inside each kernel of grain. If the malt was stewed in water that would be mashing, and much of the sugar would rinsed out of the malt. But the stewing process has a similar saccharification effect like mashing, converting some of the starch in the malt to sugar so it can be caramelized during the curing process.
Caramel Malts are available in a range of colors from 1.5°Lovibond (Cara-Pils) to about 500°Lovibond (Carafa III), almost the full range of malt colors. The caramel family includes all the malts beginning with "Cara", all the malts with "Crystal" anywhere in the name, plus a bunch of specialty malts such as Melanoidin. They contain little to no enzymes due to the roasting process, so you will need to mash them with a base malt. The recommended proportion for most caramel malts ranges from no more than 10% of the mash to 30%. As with most other advice on caramel malts, it's hard to come up with one rule that applies to all.
The "Crystal" name appears on several sub-groups in the family of Caramel Malts. The name of many crystal malts includes a number such as Crystal 60, which indicates the relative darkness, or they may have a color descriptor such as "Dark Crystal."
What is the advantage of the crystal or caramel malts? They typically produce strong, sweet flavors that can range from toffee to caramel to raisins to chocolate depending on how long and how hot they were roasted. They can be steeped without mashing to extract their flavor. Some of the sugars in these malts caramelize during kilning and become unfermentable, so crystal/caramel malts will increase the body and final sweetness of your beer.
There seems to be some confusion around crystal malts. I was recently asked what the numbers mean. I've also heard or read advice like "Use some crystal", "Use a caramel malt instead of crystal" or "Crystal malt tastes like iced tea." Let's take those one at a time.
- Crystal malt is available with a numbering scheme that ranges from 10 to 120. Those numbers refer to Degrees Lovibond (°L), which is a scale that measures the color of beer and other liquids. The newer SRM and EBC methods have replaced it for finished beer, but Lovibond lives on for malt. When you look a the malt you won't see a huge color difference between Crystal 20 and Crystal 60, but the color differences will come out when you steep them in hot water.
- If you get a suggestion to "use crystal malt", they're probably talking about Crystal 60, or possibly Crystal 40. The term "crystal" is somewhat ambiguous when used without a way to include the color. Crystal 60 is the most widely used crystal malt, so I think that's your best bet if you lack other information. If you're looking at a recipe that has been around for years, go with Crystal 40.
- Crystal is one of the Caramel malts, so you probably won't accomplish much by substituting caramel for crystal, unless you substitute another specific caramel malt for a specific reason. For example, Briess Caramel 40 is simply Briess Crystal 40 by a different name.
- One or more of the crystal malts might add a taste like iced tea depending on your personal taste appreciation, but we're talking about dozens of malts with a full range of flavors, not just one malt.
1. Beeston Crystal Malt