For people whose cookies turn brick hard after a day or so.

[Blue_true]

I tried all the web based ideas, apple slices, bread in with the cookies, ect. Nothing worked.

Then I decided to use my training as an engineer. First I tried food grade diatomaceous earth and it worked, but I was concerned about sustainability given that the organisms that became the earth were from millions of years ago, once it is dug up, it is gone.

I looked in my kitchen cabinet at the cornstarch that I keep in a sealed container to reduce clumping from moisture collection. Perfecto. Adding just less than one teaspoon per cup of flour produced wonderful cookies that retain most of their as baked softness for days. You can try natural preservatives to hold the as baked flavor, I tried one that works, but my guess is any do.

I discovered something else about cornstarch in cookie dough. A little less that a teaspoon per cup of flour keeps the cookies from hardening as they sit. Three tablespoons per cup of flour gives a hard, snappy shortbread like cookie. I thought the contrast was interesting and believe that it comes from a water-bonding dynamics change as the amount of cornstarch is changed.

[Kali]

1. you have cookies that last more than a day?

[trixie2]

3. I was going to say that!

[Blue_true]

11. I am single and don't eat a lot of sweets.

I bake batches of 12-14. There have been times where I had to force myself to stop eating them, several times I have eaten half a batch in maybe 20 minutes, not good for sugar intake. When I have had other people eat them, they are gone pretty much after they cool. The ones that sit around are the ones that I bake for myself. Occasionally I will do a big batch (around 100) for a family event, I don't have to take any back home because there are none left. Not being cocky, but I would match my cookies up against anyone's colors on this site or any site, they are really good.

[Kali]

12. it was a joke

and I could continue it by saying "you have cookies left to cool?"

[SkyDaddy7]

27. EXACTLY!!!

...You have cookies that actually get “COOL”? 🤣😂🤪😂🤣😂😂🤣😂😉

[SkyDaddy7]

28. Seriously...

Thanks for the tip!

[MFM008]

32. I like hot

Gooey cookies.

[Blue_true]

34. Similar here. I prefer hot cookies just out of the oven and cooled.

So I have to be disciplined when pulling a batch from the oven, I have eaten a whole pan before.

[AJT]

2. Great tip, thanks.....now I will have to bake cookies for testing.

[Blue_true]

13. It works beautifully, you will see.

It works really well when you have to bake up a lot of cookies before a big event, when I can't just bake them the day of.

[rusty quoin]

4. I love science.

[fierywoman]

5. Engineers are the best! (My father is a mechanical engineer.)

[applegrove]

6. Granny made bran cookies with raisins and ginger and cinnamon and

oats. They were doughy right out of the oven and so good. They were even better a few days later when they had dried a bit. I guess they were muffins of a sort.

[Blue_true]

18. I prefer flat cookies that are somewhat harder on the inside.

I can make cookies that are more breadlike inside by upping the amount of baking powder that I add, but as I pointed out, I don't like those types of cookies.

I used to bake bread but stopped after loaves would get too hard after sitting. I am now interested in baking my own burger (poultry) rolls and hotdog rolls because the commercial stuff is either too small or flavorless. I like to pack goodies in with my burgers or dogs and the commercial stuff breaks down too easily. I freeze dough (cookie and bread (when I made bread), but I would never eat bread out of a refrigerator).

[applegrove]

20. I used to bake as a teen. No longer. I don't think I even have a cookie sheet

or cake pan or whatnot. I did get a recipe for spinach muffins which I am going to make some day.

[PoindexterOglethorpe]

7. What kind of cookies are you talking about in the first place?

I make what are certifiably the world's best chocolate chip cookies. The recipe is from a cookbook from the 1930s. Apparently they didn't yet have commercial chocolate chips as the recipe calls for chopping up a bar of semi-sweet chocolate.

I am convinced I could bring about world peace with my cookies, and here's how I'd do it. We'd get the disagreeing sides together in a room with a kitchen attached. I'd bake my cookies. I'd give each side half a cookie each. More once they reach agreement. I think this would work.

When I'm at a lower altitude, when they come out of the oven they are a combination of crispy and chewy that is remarkable. Alas, at high altitude (I'm in Santa Fe at 7,000 feet) I cannot quite duplicate that, although they're still pretty good. Back when I lived in Kansas, I so much loved my cookies fresh out of the oven that once they were cooled to room temperature, as far as I was concerned they were old and stale and you could have them.

But they never turned brick hard. So I really want to know what kind of cookies and the exact recipe.

When my oldest son was in high school I'd periodically bake my chocolate chip cookies and bring them over to school to share. He attended a small (his graduating class was 45 kids) secular private school, so it was feasible to do that. During finals week they asked parents to sign up to bring goodies to school for the kids between exams. I'd show up with my chocolate chip cookies, the students, already familiar with them would say, "Oh, Poindexter's cookies!" and I just stand back and within three minutes they were all gone. I always made a double batch and had the good sense to put a couple of dozen in the teacher's lounge. I'd joke that the only reason my son graduated high school was from my cookie baking expertise.

Oh, and when I was taking classes at my local community college, I'd bake the chocolate chip cookies on test days, bring them to school still warm from the oven and say, "I expect to get an A in this class." It usually worked. All except for my calculus class where I (and isn't this strange) got the B I earned.

[Blue_playwright]

9. Um. You totally need to post that recipe!

Nt

[Blue_true]

14. I bake Chocolate Chip, Chocolate/Chip Pecan, Oatmeal/Raisin/Cranberry and Snickerdoodle.

I use a good amount of butter in my dough, a stick per 1.5 cup of flour. I also use a comparatively large amount of egg, 1 whole egg and one-half egg yolk per 1.5 cup of flour. I also use 3/4 cup white sugar per 1.5 cup of flour. I purposely pull back on the amounts of vegetable shortening and brown sugar because I get a better tasting cookie.

For the different flavors, I vary some things, for Chocolate Chip and Chocolate Chip Pecan, for example, I take out a tad of the white sugar and add a tablespoon of chocolate syrup. For Snickerdoodle, I jack up the cinnamon and of course sprinkle on cinnamon-sugar just before backing.

Does that answer your questions and give you a feel for how my cookie dough bake out?

[PoindexterOglethorpe]

17. My best guess is the large amount of egg.

I gather you have a basic recipe, the one you just described, and vary it as likewise described. You also seem to have a lot of sugar in that recipe.
Do you use both butter and vegetable shortening? I'm feeling slightly confused.

I happen to live in Santa Fe, at 7,000 feet, and the standard high altitude adjustments that people are given are simply wrong. They're told to put in more flour, which makes the baked goods even drier than they're going to get at high altitude.

[Blue_true]

21. I use butter and vegetable shortening, always have.

Like you pointed out, the amounts of sugar and egg make the cookies harder on the inside and crispier, as does the butter. But I like cookies that way. My fresh baked cookies don't stay around long is I have other people around, the hardness issue is one that I ran into with the cookies that I keep for myself. I can send you my basic cookie dough recipe on a back channel if you want it, I vary the flavors in the way that I pointed out - by varying the amount of the feature ingredient for the flavor desired.

Since you live at a much higher altitude than I do, you should have a bigger issue with moisture retention, so it would be interesting to see how my recipe works for you. I have baked my cookies in Northern California (Silicon Valley region) and North Central Florida, with the same results.

[jmbar2]

8. Another solution for hard cookies

Send them to me! I love hard crunchy cookies - the harder the better. I actually let my burn a little just to make them brittle.

I have discovered that brown sugar makes cookies a bit softer than white.

[Blue_true]

15. Brown sugar and shortening in the place of white sugar and butter are supposed to soften them.

For my white sugar, I use an unrefined white sugar from a Florida company, it is a bit tanner than refined white sugar, but largely work the same. I use organic Himalayan brown sugar instead of the fake US stuff (just white sugar with molasses added back in).

[Phentex]

10. I guess our humidity is too high here in Atlanta...

I've said before my brown sugar stays plenty soft in a Tupperware and I think we often have the opposite problem of what you describe. Things can go soft/bad quickly when it's warm and humid out. We have to be especially careful with bread. And I really DON'T like refrigerated bread!

[Blue_true]

16. I live in Florida. It gets pretty humid here. nt

[PoindexterOglethorpe]

19. Here's my chocolate chip cookie recipe.

As I mentioned above, it comes from a cookbook from the 1930s, so you'll note the proportions are a bit different from what you'll find in a modern cookbook. Apparently modern cookbook authors don't think people can handle measurements other than full, half, or one quarter.

Also note the amount of flour. It makes this recipe almost a high altitude recipe as it is.

I often swap around the white and brown sugar, because I like the resulting flavor.

Also, the usual sugar to shortening (or butter) ratio is typically 2-1. Meaning two cups of sugar for every cup butter or shortening. This recipe has a lower ratio.

Also, I don't believe I've ever seen cornstarch in a cookie recipe.

Chocolate Chip Cookies

2 ¼ cups unbleached white flour
½ teaspoon baking soda
1 teaspoon salt
1 cup shortening
½ cup brown sugar, packed
1 cup granulated sugar
2 eggs
2 teaspoons vanilla
1 package chocolate chips
1 cup chopped walnuts

Cream together the shortening and sugars. Add the vanilla and eggs, mix well. Add the dry ingredients and again mix well. Last of all add the walnuts and chocolate chips.

Bake on a lightly greased cookie sheet at 350 degrees for 12-15 minutes, depending on your oven.

Done right, these are a combination of crispy and chewy when fresh out of the oven that is amazing.

Notes: Always use real vanilla. Always. Use Crisco for the shortening, and not the butter-flavored one. The walnuts are optional, but I like them a lot.

For a variation, you can substitute butterscotch chips and pecans for the chocolate chips and walnuts, and they are likewise excellent.

[Blue_true]

22. I see some difference between my dough and yours.

All make my dough bake out harder and crispier.

We both use unbleached flour (there are two really good companies for that: King Arthur and Red's Mill).

After that differences, lot's of them.

I use a pinch of baking soda, about 3 times less salt, four times less shortening, I use butter and you don't, I use about 50% more sugar. I also add cinnamon and ground nutmeg to my cream. I also add Ginger Essential Oil to my cream as a natural antibacterial agent and I use organic citric acid (from fermented sugar cane) as a flavor preservative because of how long I keep my cookies before eating all of them.

Below is my basic cookie dough recipe:

Cream:
To a stainless steel pot add 1 stick softened cultured butter, add 1.5 tablespoon vegetable shortening, add 3/4 cup unrefined granulated sugar (can find at health food stores that sell grocery), add 1 tablespoon Himalayan Brown Sugar (health food store), add 1 teaspoon Blackstrap Molassas, add 2 drops Ginger Essential Oil, add 1/8 teaspoon organic citric acid, add 1 whole egg, add 1/2 egg yolk, add 1 1/2 teaspoon pure Vanilla extract, add 3/4 teaspoon ground cinnamon, add 1/4 teaspoon ground nutmeg. CREAM THE INGREDIENTS WITH A BEATER.

Flour:
Mix 2 cups unbleached all purpose white flour, 1/12 teaspoon baking powder, 1/6 teaspoon salt, 3/4 teaspoon cornstarch. Use a fork to thoroughly mix the ingredients. Add the flour mixture to the cream pot and mix with a sturdy spoon until the flour mixture is completely mixed in.

Flavors:
For Chocolate Chip or Chocolate Chip Pecan:
Add 1 tablespoon organic chocolate syrup to the cream before adding the flour mixture. Add 1 cup semi-sweet chocolate chips for chocolate chip or 1/2 cup semi-sweet chocolate chips and 1/2 cup chopped pecans for chocolate chip/pecan. Mix the ingredients into the cream before adding the flour mixture.

Oatmeal/Raisin/Cranberry:
Chop 1/8 cup raisins and 1/8 cup applejuice sweetened dried cranberries using a chef knife - add to cream. Add 1/2 cup of dry old fashioned oatmeal to the cream before adding the flour mixture.

Snickerdoodle:
Increase the ground cinnamon to 1 1/2 teaspoon from 3/4 teaspoon. Sprinkle cinnamon-sugar on top of the cookies before baking.

I like to make dough balls of around 1.5 tablespoon and then flatten them to 1/4 inch thick by pressing the dough balls between two plastic sandwich bags using a sturdy pancake laddle. I slow bake the cookies for 30 minutes on a silicone baking sheet, 300 degrees for 30 minutes - I occasionally check, I pull them when I see the edges turning medium golden brown.

On edit:
For those of you that have never used it, Blackstrap molasses is NOT the same as lighter molasses. That is why I use the small amount, it is stronger and saltier (also has a lot more nutrients).

Second edit: I refrigerate my cookie dough for around six hours before making dough balls. The dough freezes really well in any form.

[PoindexterOglethorpe]

23. There are very large differences between our recipes.

If you need to the creaming part with a mixer, if it's so stiff you can't really do it by hand, I'd say that's the core of your problem.

You have so much less butter and shortening, and consequently a much higher ratio of flour, I'd say that's really what's going on. More flour leads to a drier product. Which is why I'm driven crazy when I see high altitude advice as putting in more flour. No, no, no. Things are already going to come out dry at 7,000 feet.

Here are Poindexter's rules for high altitude baking:
Increase the shortening by a smidge. Maybe a tablespoon per cup.
Increase any liquid ingredients, likewise by a smidge. With my cookie recipe, I solved that problem by going from medium eggs to large or extra large.
Leave the sugar alone.
Decrease any leavening by half.
Decrease the flour by about a tablespoon per cup.

One problem is that sometimes you can't really give exact measures, as I can't with the above high altitude directions. A baker needs to know both how to follow a recipe, and when to diverge. I think you have that very well mastered.

But if you really like your cookies, then why change? I might suggest you could freeze dough balls and just bake half a dozen at a time as you want them.

[Blue_true]

24. I can cream the wet ingredients with a fork or spoon.

The mixer just makes things faster, I am sort of a lazy cook that look for shortcuts.

I live in Florida, so neither low humidity or high altitude is an issue for me.

I will mix up a batch of your cookie dough, substituting pecans for walnuts but leaving all else the same and see how that works out. I used to use much more shortening (around 3/4 cup) and baking powder and still the cookies hardened after sitting for more than a day. But I also used butter, which you do not.

Hard cookies after sitting is a pretty common complaint online, you may want to go into some of those forums.

[PoindexterOglethorpe]

25. What I often do, since I live alone,

is after a day or so freeze the remaining cookies. When I take one out to eat I thaw it in the microwave. That helps. It would work with non frozen cookies also.

I used to make my cookies with butter, in the same amount. Since butter has so much lower a burning point, they'd tend to burn on the bottom. And I wasn't all that crazy about the butter flavor. I like that shortening essentially has no flavor, so I get the vanilla, sugar, and chips flavor.

For my taste buds, walnuts are absolutely the nut for chocolate chips. When I make this recipe with butterscotch chips I use pecans. Just one of my quirks.

I also have a brownie recipe that calls for walnuts. I suppose you could easily substitute pecans. One time I got a request to make my brownies but without nuts and I said, Sure. Big mistake. That particular recipe simply didn't bake up properly without nuts.

It's interesting the way what seems to be a small detail (with nuts, without nuts) can actually matter a great deal.

[Blue_true]

26. Good point on butter browning, that is why I bake at 300 F for longer time.

I honestly have not noticed the nut, no nut difference. Was the difference in baking time? I tend to bake by sight, after a certain amount of time has elapsed I start looking at the edge of the cookies, I like when the edge up to around 1/8 inch is medium golden.

I don't care much for walnuts, they don't have enough flavor for me. I should be able to see where I come up short with your recipe using pecans and make adjustments which should not impact the basic investigation that I will be doing.

I have found that unfreezing one cookie at a time causes me to eat too many, so I back 6-9 at a time, for some reason that causes me not to eat as many in a short span. One thing that I have found is that cookies that I freeze for say 2-3 weeks are insanely delicious to me when I bake them, just not delicious but eye-rolling delicious.

I will run you recipe by your book this weekend, I have everything that I need. I will pick up walnuts even if I won't do more than taste the cookies for flavor and texture.

[PoindexterOglethorpe]

31. You do what works for you about how many cookies

you thaw.

To me the walnuts go with chocolate, and pecans go with butterscotch chips. When I bake banana bread I put in pecans. I have not fiddled with oven temperatures when I'm baking. Because I'm at high altitude some of my high altitude recipes are very specific on baking times (like 17 minutes, or 23 minutes) but that's for my oven. Things take slightly longer to bake or cook here, as water boils at a slightly lower temperature, so pasta, just to name one thing, will take longer here. I know ovens can vary, and hopefully any baker knows her oven and knows if she typically needs to bake longer or shorter.

Here's my brownie recipe with my notes. It's the sea level recipe.

4 oz unsweetened chocolate
2/3 cup shortening
2 cups sugar
3 large or extra large eggs
1 teaspoon vanilla
1 ¼ cups all purpose flour
1 teaspoon baking powder
1 teaspoon salt
1 cup chopped nuts.

Melt chocolate and shortening in a saucepan over low heat. Remove from heat. Mix in sugar, eggs, and vanilla. Then add the flour, baking powder and salt. Last stir in the chopped nuts. Spread in a greased glass or pyrex pan and bake at 350° for thirty minutes. Do not overbake. Cool before cutting.

Notes: I use Crisco for the shortening. I will warn you away from a butter-flavored shortening or a bargain brand. I also always use real vanilla, not imitation. For nuts I use walnuts.

This is very important: If you do not like nuts in your brownies, do not waste your time with this recipe. For some reason it does not bake up properly without the nuts.

This recipe comes from my Betty Crocker Cookbook that I bought some time in the 1970s, and I suspect this specific recipe dates back at least to the 1950s and possibly much earlier. The recipe in the cookbook calls for 4 eggs, but eggs tended to be a bit smaller back then. If you use medium eggs go for four of them. I tend to buy extra-large and three of those are just right for this recipe.

Regarding the eggs. I have no idea when large and extra large eggs became commonly available. But certain older recipes will call for what seems like too many eggs, and the modern cook needs to figure it out and make adjustments. For me the older recipes are much better and more interesting, especially if you're aware of things like the egg size.

Something else that's crucial. I have only ever made this recipe using a glass pan. I have no idea how it would bake up in a metal pan, but probably not as well.

When I lived in Kansas I made my chocolate chip cookies with medium eggs and it was with that size eggs that I could get that incredible crispy/chewy combination right out of the oven. It does not seem possible to duplicate at high altitude. Sigh.

A bit of a history on this brownie recipe. A few years ago I was needing to bake some kind of sweet/dessert and only had three eggs, but they were large or extra large eggs. So I decided, what the heck and made this. It was here in Santa Fe, so I made the high altitude adjustments on the fly. As I said before, when I tried to make this specific recipe without nuts (and I'm sure pecans would work as well, especially for someone who prefers them) it just didn't bake up right. I do respect those who can't do nuts or simply don't care for them in their brownies, but since I like them I've never been motivated to find an alternative recipe without nuts. I'm sure there are plenty of good ones out there.

A few years back I worked the information desk at the local hospital. For a while I was in the habit of baking cookies, or a cake, or brownies, or banana bread, or something, on Fridays and bringing them into the hospital to share. I made certain that the hospital operators got some, because they were my resource for things I didn't already know. It was almost embarrassing how much people loved what I brought. It was so clear that many people had simply never had something baked from scratch. Even bakeries don't do from scratch baking very much any more. I am yet to find a chocolate chip cookie that's as good as mine. Or a chocolate cake. I use the recipe off the back of the Hershey's cocoa box, do as a sheet cake (I'm a total failure at layers) and make a butter cream frosting. The awful stuff that's labelled frosting that comes in a can is dreadful. But people think they haven't the time to make the real thing and they're wrong.

Early in my marriage I baked a birthday cake for my husband, and bought a mix because I thought it would be faster than my usual from scratch recipe. Boy, was I wrong. I saved five, maybe ten minutes. It wasn't worth it. That was the last time (other than when baking goodies for a grade school class party and I had to make cherry flavored cupcakes and it broke my heart to buy and fix the mix) I ever baked from a box.

Now I do understand how busy a lot of people are, and I understand that not everyone enjoys cooking, although I feel fairly confident that anyone that browses this group does.

[MFM008]

33. I need to test both

Recipes.
Send me the cookies!

[Blue_true]

35. I mixed up a batch of your cookie dough just after breakfast.

I used chopped walnuts and followed your instructions exactly.

Your dough was a little stiffer than mine, but you also use a buttload of chocolate and nuts whereas I don't. The mixing time was about the same as for my dough, but any decent cookie maker can usually mix dough pretty fast.

I have something to do for the next few hours, so I have the dough in the fridge setting. I will pull dough and bake it as you laid out tonight. I have a really good oven so there should not be issues with temperature control.

I must admit, as I smelled your dough as it took form, I was tempted to add cinnamon and nutmeg but avoided that because I want to run your recipe as it on the first pass.

Will let you know how the cookies work out.

[Blue_true]

38. I got back home and panned and baked your dough recipe, what happened.

When I took the dough out of the fridge and scooped out some I was really surprised that it had not set any. That made me think that it would be overly runny during baking, which they did.

I baked for the time reced and watched as they baked some more. The cookies looked delicate so I allowed them to cool before trying one.

The cookies are much softer than mine-which tend to be crunchy on the edges and across the shell of the cookie and softer inside. Your cookies had a very gooey mouth feel, which should be great for people that like that, but I suggest that they add 1/2 cup flour and a couple tablespoons of sugar to the dough recipe.

The flavor of the cookies was very good, rich decadent chocolate chip nut cookies. I likely will add some cinnamon and nutmeg to my adaptation of the recipe.

In all, it seems that at my elevation, adding a bit more flour and sugar is advisable. The rest of what I would do is simply a matter of how I value smell and taste when compared to you.

Thanks for the recipe, I will adapt it as a butter-free recipe, some people prefer that.

I will let some cookies sit around in a closed container to see how they age.

[PoindexterOglethorpe]

40. It is a soft dough.

I've never refrigerated it, because it just doesn't need to.

Did you bake at 350 degrees? What kind of a cookie sheet do you use? I use a metal sheet with low sides, lightly coated in Crisco. If you use another material, such as the silicone, which I've never used, I'm sure they will bake very differently.

A flat metal cookie sheet also does not bake properly in my experience.

As we both know, all those details matter.

[Blue_true]

41. I used a flat aluminum sheet with low sides.

I lubed the pan lightly with Crisco as you indicated. You are likely right about the low pan sides, a lot of reflected heat may have escaped instead of immediately coming back at the cookie centers. I baked at 350 as you described in your recipe post.

I will adjust the recipe for my techniques, it is a really good, easy to perform recipe, so I will use it for people that don't want butter in their cookies.

[PoindexterOglethorpe]

42. Well I am glad you like it.

That's gratifying.

[Blue_true]

43. It is a very easy to do, good recipe.

With adjustments for my part of the country and kitchen, it will be ideal for some relatives.

I think the hardening of my cookies come from the high butter use. I have used cornstarch to keep them soft and another poster said Pros use glycerine. So the thread has been informative, at least for me because I had not heard about glycerine as a solution for hard cookies and bread.

[PoindexterOglethorpe]

44. I don't do complicated recipes.

Given that I think the proportions are already a lot like a high altitude recipe, I expect adding more flour at sea level would help.

[Ohiogal]

29. I make cookies just about every week

Last edited Sat May 4, 2019, 10:51 AM - Edit history (1)

Even though my sons are all adults.

My choc chip cookie recipe includes a “secret ingredient “ - 4 TB real maple syrup. Everyone who’s had them really seems to like them. I prefer to use the mini chips.

This past week I just made Snickerdoodles and Almond Biscotti.

[Blue_true]

30. I have been toying with the idea of using Flaxseed oil to replace some butter

Flaxseed oil has a slightly lower smoke point than butter, that is the thing that keeps me away from it.

What does the maple syrup do for your cookies (in terms of what it replaces and how it affects cookie texture)?

[Ohiogal]

36. I don't know that it replaces anything

but it gives the cookies a really nice flavor.

They’re kind of chewy which I like, and they’re better eaten within 24 hours, that is just my opinion. So I leave out what we’re going to eat and freeze the rest.

[sir pball]

37. Glycerin is the gold standard for maintaining moistness in baked goods

It's completely natural and perfectly safe; you can find vegetable glycerin on Amazon for just a few bucks. I'm not a pastry chef so I can't speak in too much detail how it's used; I know the pastry chef at my last job added about a cup to the cakes (so maybe 2T for a home sized batch) but not what se did with the cookies. It is a bit sweet and also functions as a wet ingredient so you may need to reduce the sugar content a bit. It's also very useful for keeping icings from drying out and getting that crackly coating, it's why the factory stuff stays glossy, and if you do fondant it's almost essential for the glossiness. At any rate, it might be something worth looking into as well.

[Blue_true]

39. Makes a lot of sense!!!!

Glycerin is a hydroscopic medium chain alcohol. It is sweet, so anyone using it should adjust the sugar in their recipe down some, I would guess 1 tablespoon of sugar for each tablespoon of glycerin added, the sweetness of the two is close - or just try adding 1 TEASPOON of glycerin to the recipe and leaving all else alone, then adjust from there.

Like the poster pointed out, glycerine is perfectly safe to use, you likely already have it in a lot of food and health and beauty aid products that you use. Just be sure to buy the right glycerine. Because of what I do with my company, I have plenty of kosher vegetable glycerin handy and know something about it (other than it's use in baked products). Glycerin can come from animals or some plants, it also is a byproduct of biofuel manufacture - so anyone using it should be sure to buy certified kosher vegetable glycerine since it does not have the drawback of being an animal byproduct or potentially having undesired toxins in it.

It can likely be found at health food stores since it can be used as a sugar substitute in liquids. I buy my glycerin wholesale so I have never checked for it at the local health food store that I use.