There’s no deep, dark mystery to turning out a velvety-smooth batch of fudge.

It’s like a fun activity you’d perform alongside Bill Nye the Science Guy in a beginning class focused on controlling the size of sugar crystals. If the sugar crystals get too large, you’ll end up with grainy fudge. Not an entirely earth-shattering problem, but nice, delicate sugar crystal formation is something to shoot for, because it yields smooth fudge. So here are three basic concepts to keep in mind:

1. Temperature: Fudge is cooked to the “soft-ball” stage. There’s only one reliable way to know when your fudge-to-be has reached this point, and that’s by using a candy thermometer. The ideal soft-ball stage is 238 degrees, but the acceptable range is 236 to 240 degrees.

2. Appropriate blend and balance of ingredients: Your goal is to end up with nice delicate sugar crystals, but without some specific ingredients that are natural inhibitors of their size, the crystals tend to get too big. Ingredients that, for different reasons, help prevent large crystal formation include corn syrup, cream of tartar, milk, butter and chocolate. You don’t need all of them in any given fudge recipe, but the interactions between those that are used form a high-wire balancing act that shouldn’t be tampered with — unless you know what you’re doing. So if you’ve got a tried-and-true fudge recipe, don’t fiddle with it.

3. Agitation, when and when not to do it: Some people think that at the point where you are beating the fudge (this is after it has reached the soft-ball stage and been removed from the burner), you are causing it to harden. But you aren’t. Cooling does that. The beating is done to make sure that crystalization starts in as many places as possible. You are actually agitating the crystals into action. Then, as the fudge cools, the tendency to crystalization increases until a lovely network of small sugar crystals have all attached themselves to each other, forming an evenly smooth mixture. On the other hand, if the fudge is agitated too much while it’s cooling, the crystalization process will start too early. The resulting crystals will be fewer in number and larger in size.

Other thoughts: Fudge recipes using marshmallows or marshmallow cream take advantage of the fact that the egg whites and gelatin in marshmallows coat the sugar crystals as they form, which keeps them small and produces an unusually creamy fudge.

You can also produce microwave fudge by melting together sweetened condensed milk, chocolate and butter (in specific proportions). The sweetened condensed milk is a boiled-down, concentrated sugar syrup, and by adding the acidic melted chocolate to that, the proteins in the milk become firm. Once the mixture reaches room temperature, these proteins are even firmer, resulting in a set fudge of creamy consistency.

Rich Cocoa Fudge

3 cups sugar

2/3 cup cocoa powder, such as Hershey’s Special Dark Cocoa powder

1/8 teaspoon salt

1-1/2 cups milk

1/4 cup butter ( 1/2 stick)

1 teaspoon vanilla extract

Line bottom and sides of an 8-by-8 or 9-by-9-inch pan with parchment paper (each layer of parchment paper should be cut to 8 or 9 inches by 14 inches, and grease it well with the butter or nonstick cooking spray.

Mix sugar, cocoa and salt in heavy 4-quart saucepan; stir in milk. Cook over medium heat, stirring constantly, until mixture comes to a full rolling boil. Boil, without stirring, until mixture reaches 234 degrees on candy thermometer (soft-ball stage).

Remove from heat. Add butter and vanilla. Do not stir. Cool at room temperature to 110 degrees. Beat with wooden spoon until fudge thickens and just begins to lose some of its gloss (about 7 minutes). Quickly spread in the prepared pan; cool completely. Cut into squares. Store in tightly covered container at room temperature.

NOTE: For best results, do not double this recipe. Hershey claims this is one of its most requested recipes, but also one of its most difficult. The directions must be followed exactly. Beat too little and the fudge is too soft. Beat too long and it becomes hard and sugary.

Carnation Famous Fudge

About 1 tablespoon butter for greasing pan (or use nonstick vegetable oil cooking spray)

1-1/2 cups granulated sugar

1 (5-ounce) can evaporated milk (2/3 cup)

1/4 teaspoon salt

2 cups miniature marshmallows

1-1/2 cups semi-sweet chocolate chips

1/2 cup chopped roasted pecans or walnuts (optional)

1 teaspoon vanilla extract

Line bottom and sides of an 8-by-8-inch pan with two strips of parchment paper (each layer of parchment paper should be cut to 8 by 14 inches so you can align one strip in one direction and the second strip in the other direction) and grease well with the butter or nonstick cooking spray.

Combine the sugar, evaporated milk, butter and salt in medium, heavy-duty saucepan. Bring to a full rolling boil over medium heat, stirring constantly. Boil, stirring constantly, for 4 to 5 minutes. Remove from heat.

Stir in marshmallows, morsels, nuts and vanilla extract. Stir vigorously for 1 minute or until marshmallows are melted. Pour into the prepared baking pan; refrigerate for 2 hours or until firm. Lift from pan and place on cutting board and cut into desired size pieces.

For milk chocolate fudge: Substitute 1-3/4 cups (11.5 ounces) Nestle Toll House Milk Chocolate Morsels for the semi-sweet chocolate chips.

For butterscotch fudge: Substitute 1-2/3 cups (11 ounces) Nestle Toll House Butterscotch Flavored Morsels for the semi-sweet chocolate chips.

For peanutty chocolate fudge: Substitute 1-2/3 cups (11 ounces) Nestle Toll House Peanut Butter and Milk Chocolate Morsels for semi-sweet chocolate chips and 1/2 cup chopped peanuts for pecans or walnuts.

Sinfully Easy Fudge

This is “Cook-Wise” cookbook author and food scientist Shirley C. Corriher’s adaptation of a recipe from Rosanne Green.

1 tablespoon butter for greasing pan (or use nonstick vegetable oil cooking spray)

1 cup pecan or walnut pieces

1 tablespoon butter

1/8 teaspoon salt

1 (14-ounce) can sweetened condensed milk

7 ounces milk chocolate chips, coarsely chopped

11 ounces semi-sweet chocolate chips or good quality semi-sweet chocolate such as Scharffen Berger or Hershey’s Special Dark, coarsely chopped into 1/4-inch pieces)

1 teaspoon vanilla extract

Preheat oven to 350 degrees.

Line bottom and sides of an 8-by-8-inch pan with two strips of parchment paper (each layer of parchment paper should be cut to 8-by-14-inches so you can align one strip in one direction and the second strip in the other direction) and grease well with the butter or nonstick cooking spray.

Spread the nuts on a medium baking sheet and roast in the 350-degree oven until lightly browned, 10 to 12 minutes. While the nuts are hot, stir in the 1 tablespoon butter and sprinkle with the salt.

Combine the condensed milk and all of the chocolate (the milk chocolate and semi-sweet chocolate) in a large glass microwaveable bowl or 4-cup Pyrex measuring container and melt in the microwave at 50 percent power for 3 minutes, stopping the microwave to stir frequently (see stove-top directions below). As soon as the chocolate is melted, remove from the microwave and stir in the vanilla and roasted nuts. Pour into the prepared pan. Refrigerate to cool and set.

Lift the cooled fudge from pan and cut into desired size pieces.

Stove-top method: Simply heat chocolate and condensed milk over low to medium heat in heavy-bottomed saucepan, stirring constantly, until the chocolate melts. Remove from heat and stir in the vanilla and roasted nuts. Pour into the prepared pans and proceed as above.

Cappuccino Fudge

Another one of the fool-proof fudges that doesn’t deal with “soft-ball” stages. Speedy to make, but remember, the trade-off is a slightly less creamy texture.

1 tablespoon butter for greasing pan (or use nonstick vegetable oil cooking spray)

1 tablespoon boiling water

1 tablespoon instant coffee granules or crystals

1 teaspoon cinnamon

2-1/2 cups sugar

1/2 cup butter

1 (5-ounce) can evaporated milk (2/3 cup)

1 (7-ounce) jar marshmallow creme (2 cups)

12 ounces semi-sweet chocolate chips

1 teaspoon vanilla

Line bottom and sides of a 13-by-9-inch pan with parchment with two strips of parchment paper, cutting each strip to extend over the side of the pan and grease well with the butter or nonstick cooking spray.

In small dish, combine the boiling water, instant coffee and cinnamon; set aside.

In large saucepan, combine the sugar with the 1/2 cup of butter, and evaporated milk. Bring to a boil over medium heat, stirring constantly. Boil 5 minutes, stirring constantly. Remove from heat, then stir in the marshmallow cream, chocolate chips, vanilla and coffee-cinnamon mixture; blend until smooth.

Pour into the prepared pan. Cool to room temperature. Once firm, lift the fudge from the pan to cut into desired size pieces.

Recipe from “The Pillsbury Chocolate Lovers Cookbook.”

Jan Roberts-Dominguez is a Corvallis food writer, artist and author of “Oregon Hazelnut Country, the Food, the Drink, the Spirit.” Email her at janrd@proaxis.com.