Questions about the chemical composition or properties of ingredients and dishes.

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15
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4answers
2k views

How long is garlic butter safe, and why is it not a botulism risk like garlic in oil?

I've been making garlic butter for years, storing it for months at a time. When I read that garlic-in-oil can grow dangerous amounts of botulinum toxins after similar lengths of time, I wondered how ...
12
votes
2answers
783 views

How deeply will the flavors in a brine penetrate chicken? (experiment results)

I'm not asking about salt or "juiciness". I think there is enough evidence here and elsewhere to answer that question with "pretty deep, or all the way to the bone". My question concerns spices and ...
11
votes
1answer
2k views

Why do people recommend cream of tartar when whipping egg whites to the exclusion of all other acids?

Virtually every single egg white recipe will say add some cream of tartar to egg whites to help them whip better because the cream of tartar will lower the pH and make it more stable. But if all it's ...
11
votes
2answers
1k views

Coffee foam vs. Tea foam

One sign of really good fresh well-roasted coffee beans is foam. When you pour hot water into the French press, it foams, often forming a head up to 2" high. And when you use an espresso machine, ...
9
votes
1answer
1k views

What determines the 'saltiness' of salt?

I've bought two brands of salt that are completely different in terms of 'salt' concentration(not sure if this is the correct terminology). I realized this because I needed three or four times more ...
8
votes
2answers
1k views

Do breadcrumbs really act as a binder in meat preparations?

I routinely hear that breadcrumbs are added to burgers and meatballs to bind them. For example, see the answers to this question: how to stop meatballs falling apart. On the other hand, I have heard ...
8
votes
2answers
547 views

How does hydration of a sourdough affect baking features?

Looking at different recipes for sourdough starters, there's everything from a mix as dry as cookie dough to as wet as gruel. In this (danish) recipe from the acclaimed chef Claus Meyer of a pretty ...
8
votes
1answer
2k views

What turned my garlic purple?

I commonly use a technique when caramelizing onions, in which I add the sliced onions to a pan with salt, oil, and water. The water softens the onions and helps cook them evenly such that by the time ...
8
votes
1answer
144 views

Does the speed of opening of a bottle of wine influence its flavour?

While having a (good) bootle of wine at a friends place I've been told the following: The bottle should be uncorked slowly and silently, not to spoil its bouquet. This statement came as ...
7
votes
1answer
238 views

What happens with bread at >= 94˚C/201˚F? Or: Is temperature a reliable indicator of doneness?

So I baked a rye bread last night (in a bread pan). It was a new recipe for me and I had to adjust some things in it due to missing ingredients, so I could not fully rely on the time and temperature ...
7
votes
2answers
9k views

homemade mint extract

I've got some mint in the yard (I think it's apple mint, as the leaves are very fuzzy and rounded) from which I'd like to make mint extract. No specific use in mind (except perhaps insect repellent), ...
7
votes
1answer
5k views

What is the purpose of oil or butter in bread?

Specifically in wheat and potato breads, what is the purpose of adding oil or butter to the dough? I have always assumed it was just for flavor, but I suspect there is some background chemical ...
7
votes
1answer
1k views

Cooking Chemistry: lemon juice/soymilk buttermilk substitute turning bitter and 'rising'

I made a soup recipe the other night (mainly potato, spinach, and veggie broth) that called for buttermilk. I substituted soymilk and lemon juice, reading online that that was a good substitution for ...
6
votes
2answers
910 views

What factors affect collagen to gelatin conversion?

I have a bunch of oxtails I've been braising for hours in an adobo sauce and they remain awfully tough. What I'd love to see happen is for that abundant connective tissue to melt away and coat each ...
6
votes
2answers
499 views

How do I calculate the final acidity of homemade vinegar?

I am making vinegar by mixing vinegar (containing the mother) and wine, and then allowing fermentation to occur. I am wondering how to calculate the final % acidity. Assume: I know the initial ...
5
votes
1answer
210 views

The name or chemical compound responsible for a specific quality of some spices (numbness)

I'm putting together the results of a kitchen experiment and I'd like to be able to identify a phenomenon that I've noticed when using certain spices. I've felt it in some of what are often called ...
5
votes
1answer
313 views

How can I tell which fruits etc. contain proteases?

After my second attempt at making a ginger mousse with gelatin and finding that it fails, I've discovered that fresh ginger contains a protease. I knew that pineapple does, and that it complicates ...
4
votes
2answers
3k views

Why do uncooked frostings that contain milk not need to be refrigerated?

I have seen (and used) recipes for icing and glaze that use uncooked milk in them, yet they do not need to be refrigerated. (For example, one with powdered sugar, milk, vanilla and butter or ...
4
votes
1answer
275 views

What are the grey-black specks that appear when whipping cream in stainless steel bowl?

When we whip cream by hand in a stainless steel bowl, with a metal whisk, small grey specks, ~0.5-1mm in size, appear in the cream. The specks are squishy and can easily be smeared out. See attached ...
4
votes
2answers
199 views

Food-safe rotary evaporator grease

For those of you who have rotary evaporators or other chemistry glassware in the kitchen, what do you use to grease the ground glass taper/ ball joints so that the lubricant does not either absorb or ...
4
votes
1answer
3k views

what makes red tomato sauce turn orange in colour?

I have noticed that tomato sauce (having started with deep red tomatoes) can turn orange. The colour change isn't from mixing in an ingredient of different colour such as cream. It seems to occur in ...
4
votes
2answers
390 views

By what reactions do moisture and light steal away my coffee's freshness?

Typically, the standard advice for prolonging your coffee is to store it in an air-tight, light-tight, dry container. At a chemical level, what happens when coffee is left in humid or sunny conditions ...
4
votes
4answers
4k views

Why does salt prevent soy milk from curdling in hot coffee?

As many people have experienced, soy milk will often curdle in hot coffee. I've experienced this myself with both instant and fresh coffee, and with my homemade soy milk (not my favorite soy milk ...
4
votes
2answers
354 views

Estimating the fat content of homemade chicken foot gelatin

I recently simmered a pot of chicken feet (including skin) for the first time and made an astonishingly gelatinous gelatin. It's clearly suffused with chicken fat, but I have no idea how much -- I ...
3
votes
1answer
641 views

How come mere water buffalo milk and lemon juice mixture turn into yogurt?

Yogurt is produced by the fermentation of lactose in milk by the bacteria of yogurt-ferment. Without those bacteria it is not possible to make yogurt. But surprisingly, water buffalo milk and lemon ...
3
votes
2answers
302 views

Create hot “sauce” from capsaicin extract

There are a lot of hot sauces like "Blairs Mega Death" with more than 500.000 scoville heat units. However, they do have some odd taste, which I don't really like. So I'm thinking of creating a sauce ...
3
votes
3answers
2k views

Why does strata have to come to room temperature before baking?

I've made strata a few times before, usually for brunches where I have a number of guests coming over and don't want to spend all my time in the kitchen. I always follow instructions in the recipe; I ...
3
votes
2answers
181 views

All else held equal, does a pot of tea have more total caffeine than a mug?

Let's say you have one tea bag and can either brew it in a mug of boiling water, or a larger tea kettle of boiling water. The temperature, steeping time, type of tea bag, etc. are held constant. ...
3
votes
1answer
90 views

Vinegar in stock

One day I finished cooking a beef stock. When I poured the stock into a glass bowl and added some vinegar, a cloudy precipitate formed and remained suspended in the stock, leaving it somewhat cloudy. ...
3
votes
1answer
981 views

Differences between gel and gelatine

Are they physically different? If so, what is the difference, between a gel and gelatine, or it's proccesses gelation and gelling (gelatinization. gelatinisation)?
3
votes
3answers
2k views

Dissolving Egg Shell

I know that an egg shell is made up of approximately 92% Calcium Carbonate. The remaining percentage of the mass is a protein matrix. I know that vinegar (5% acetic acid) dissolves the Calcium ...
3
votes
1answer
196 views

Why brewed coffee in a pot needs a lid?

Coffee in an electric drip brewer (a model like this) goes all murky brown and opaque very fast, when the pot is left without a lid. With lid, it stays translucent and bright dark brown for quite a ...
3
votes
0answers
63 views

Why use citric acid and sodium hexametaphosphate in cheese sauce?

I was watching a YouTube video from ChefSteps on how to make cheese sauce. They used sodium citrate and sodium hexametaphosphate. What are the reasons for including these in the recipe? What are the ...
2
votes
2answers
1k views

PH and sour / acid taste

I had always thought low pH foods had a noticeable sour (acid) taste, and vice-versa. But when reading The Bread Builders by Daniel Wing & Allan Scott, on page 54, it says: The sour taste of ...
2
votes
1answer
236 views

Flavor and Chemical Composition of Thyme

What is the flavor of Thyme? What chemicals give it this flavor?
2
votes
1answer
818 views

Why should I add salt to my curries?

I've been advised by a friend of mine that I have to add salt to my curries if I want the spices to come out and not leave me with a bland curry. Now after being a doubter, as I never add salt to my ...
2
votes
1answer
138 views

Separating Chlorophyll didn't work

I tried to extract chlorophyll from spinach by blending up some spinach and water and straining out the green juice, then heating the juice. I've done it before, but this time, it wouldn't separate. ...
1
vote
3answers
688 views

What chemical(s) gives molasses its flavor so that it is used as an ingredient?

I'm curious why there isn't a zero-calorie molasses substitute. The USDA nutrient database lists a bunch of minerals, but what is it that gives it the "taste" of molasses?
1
vote
1answer
121 views

Why does spinach lose its texture when cooked?

I know that cooking spinach until it loses its texture is called wilting, but what is the chemical process that is going on. It it losing moisture? If so why does it look so moist? Thanks!
1
vote
1answer
194 views

How can I get a syrupy “mouth-feel” in sugar-free syrup?

I viscerally hate low calorie sugar replacements - all of them, including Splenda (sucralose), except in one application. In my iced coffee I like sugar-free hazelnut syrup. The brand that I've been ...
1
vote
2answers
884 views

How can I clean these brown iron stains in my pot?

I use a big aluminium pot to boil water. I think the water contains iron because after 4-6 months, the inside of the pot is full of brown stains. The colour is just like ferric. There are lots of ...
1
vote
1answer
237 views

Why does chewing gum sometimes change its texture

Although this is more a general food related question, I wonder why chewing gum sometimes changes its texture and looses its chewy quality?
1
vote
0answers
60 views

Sourcing for Carrageenan [closed]

Many softgels for pills are apparently made from carrageenan. Is it possible to process these softgels back into "pure" carrageenan? Or, rather, is it possible to use these softgels in food that ...
0
votes
1answer
243 views

Is it possible to thicken frozen cream?

I know you can use frozen cream for cooking applications such as in gratin, but can I thicken the cream? By thicken, I mean making it into something like a bechamel sauce. Would I pour the cream in ...