Making dark invert syrup in a pressure cooker

[z-bob]

I've mentioned this in one of the other threads on brewing English-style ales. But I think it's a bit off-topic there, and also worthy of its own discussion. Sucrose (cane or beet sugar) in water begins to hydrolyzes into glucose and fructose at 236°F. If you continue cooking it, the fructose caramelizes into all sorts of dark and flavorful compounds at about the same temperature; the glucose and any leftover sucrose don't caramelize until 320°F. The usual way to make invert sugar is long cooking and constant stirring in an open pot. As the water boils away, the temperature rises, and you hold it at 236 for a long time for the inversion to take place. I wondered if you could do the same thing using a pressure cooker to get the temperature above 236. No stirring required.

I bought a 4 pound bag of unbleached cane sugar at Aldi. It's a very light beige color and cost just a little more than white granulated sugar. I divided it into four 1.5 pint canning jars and added 8 ounces of hot distilled water to the first two; that looked like too much water so I added 6 ounces to the others. Added 1/8 tsp of citric acid to each jar. Stirred them up until the sugar was suspended then put them in a big pressure canner (without lids) and processed at 15 lbs for about an hour. When I took them out, they were dark brown; the two jars with more water were slightly darker, and the other two had almost 1/2 inch of undissolved sugar at the bottom where it had settled out. I stirred those 2 up while still hot and assumed it would all seize up when it cooled. Instead the sugar dissolved and all 4 jars got a little darker and almost matched in color.

My plan was to end up with 4 pint jars, each with one pound of sugar (closer to 1.5 pounds of syrup) but I ended up with too much syrup and it was also thinner than I wanted. So I dumped it all into a stainless steel stockpot and simmered it for a half hour to reduce it. And it got darker still. I reduced it a little too far; had 3 full jars and one jar about 1/3 full. The stuff was very thick and tar-like, but it tastes good. Slightly bitter, but not burned. This was about 2 weeks ago. I realized yesterday that I could transfer enough from the full jars into the partial jar to make them all have about the same amount, then top up with boiling water. So that's what I did last night. Then I put canning lids on them and processed them at 10 lbs for about 20 minutes. Now I have four sealed pint jars of dark invert syrup. I don't know if it's Invert #3, but it's a reddish almost-black.

I will take what I've learned here and try to simplify it next time. Use much less water (probably 15 to 20% by weight), and cook it on the stove just to dissolve all the sugar. Pour into hot jars, add water to top them up if necessary, then process for an hour or so. And will probably use plain white sugar. But that will be a while because I need to use this first.

I will try to get a pic of the finished jars tonight or this weekend.

 

[thehaze]

4 days ago I brewed a sort of a mutant belgian-style beer, which used 3 types of syrups I've made prior to the brew day.

1 syrup was made from natural dried, dates, raisins, plums and apricots. Total amount of fruit was around 630 gr or 1.4 lbs. I cut those in bits and added them to a 5 L pot with 2 L of water. Medium heat ( ïnduction cooktop ) all the time. At some point I strained the fruit out. I boiled until I was left with around 1.3 lbs of syrup. I let that cool down. It smelled and tasted like dried dates, raisins, brown sugar, dark fruit and actually quite belgian.

The other two were inverted syrups: 1 was a bright red and the other was dark ( more like dark mahogany ). The process was the same for both: take 200-250 gr of beet sugar added a half cup of water ( enough to barely cover the sugar in the pan ). Low to medium heat enough for a continous gentle simmer. No stirring. The water will evaporate at some point and the sugar will begin to change colour/caramelize. The bubbles that form during this process also indicate the colour of the syrup. When you reached the desired colour, take off the heat and add 800-1000 gr of beet sugar and 1-1.5 liters of boiloing water. Do not add cold water or anything below boiling temperature. Add a quart or half of lemon. Squeeze the juice and add the lemon as well. Now low to medium simmer until you get the consistency you want. This video was a great help for me:

Now I wanted some different from the red syrup, so I added 1 lime, 1 lemon and 1 blood orange, all cut in quarts. The red syrup was delicious, with obvious citrussy notes. Very pleasent. The acid is added to stop further caramelization, but I guess you knew that.

This was the thread I posted some pictures in: https://www.homebrewtalk.com/forum/threads/belgian-ale-with-home-made-syrups.663333/

I remade the dark syrup and this time it came out extremely well. The tricky thing is to stop before it burns too much and evaporates too much water, after the caramelization was stopped. The beer is now fermenting and hopefully be ready in a 3-4 weeks.

 

[z-bob]

Interesting video. But it's odd that he caramelizes the sucrose, then adds more sugar and inverts it. Why not invert the whole amount first and then stop the caramelization when it reaches the right color? Did he specifically want sucrose caramel instead of fructose?

 

[thehaze]

You get glucose and fructose once you add acid to. Isn't that how it works? ( I may have gotten that wrong ) I followed the steps shown in the video and the syrups that came out were delicious and very distinct from eachother. If you are adding acid before water evaporates, you will not get any caramelization.

 

[z-bob]

You get glucose and fructose once you add acid to. Isn't that how it works? ( I may have gotten that wrong ) I followed the steps shown in the video and the syrups that came out were delicious and very distinct from eachother. If you are adding acid before water evaporates, you will not get any caramelization.

The acid greatly increases the rate the sugar hydrolyzes into to fructose and glucose, and it inhibits browning reactions (Maillard reactions). You get glucose and fructose eventually with just sugar and water, but it takes a lot longer and might require a little higher temperature. Acid does not do anything that I'm aware of to caramelization, other than make more fructose available earlier. Fructose caramelizes much easier than sucrose or glucose. Without the acid, you don't get Maillard reactions anyway because they require what's called a "reducing sugar", and sucrose is not a reducing sugar. (glucose and fructose are) All I can think of is he specifically wanted caramelized sucrose instead of fructose. Maybe it tastes different?

I'm not trying to argue with you The way you did it worked, but it might not have worked the way you think it did.

 

[WestMichBrewer]

1 syrup was made from natural dried, dates, raisins, plums and apricots. Total amount of fruit was around 630 gr or 1.4 lbs. I cut those in bits and added them to a 5 L pot with 2 L of water. Medium heat ( ïnduction cooktop ) all the time. At some point I strained the fruit out. I boiled until I was left with around 1.3 lbs of syrup. I let that cool down. It smelled and tasted like dried dates, raisins, brown sugar, dark fruit and actually quite belgian.

This sounds really cool and interesting.

 

[z-bob]

Wife is out of town today; I'm home early, and the pressure cooker makes her nervous. So I moved my schedule up. I'm making another batch today:

4 pounds of white granulated sugar
1 pound of distilled water (a pint should be close enough)
1/2 tsp cream of tartar

Dump it all in a big saucepan (I think it was a 3 quart.) Cook and stir over medium heat until the sugar is all dissolved. It was about 225 degrees. It wasn't quite clear because it had little bubbles in it. I turned off the heat and put a lid on it while I got the jars ready.

Ladle into four hot 1 pint canning jars, dividing it evenly among the jars. Top up with water to leave about 1/2 inch of headspace (didn't take much, a tablespoon or so). Seal with 2-piece canning lids and process in a pressure canner at 15 pounds for an hour. I'm 10 minutes into this last step now. If the syrup isn't dark enough when I take them out, I might put them back and process a little longer.

 

[tizoc]

Hi @z-bob, did you use this syrup in a brew? did you like the results?

 

[z-bob]

I have used it in a pale ale; I thought it worked well, but I have never used the real stuff to compare it. I also made a mead using half this stuff and half honey; kind of a bochet without boiling the honey. The syrup added a little bitterness that I kind of like. Again, I've never tasted real bochet so I don't know if it worked or not.

I have a few jars left. Going to use one soon in something strong and add brett from a Orval bottle and see what I get.

IIRC, I also made some adding the dry sugar directly to the canning jars, top up with hot water and process in the pressure cooker. That didn't work as well; the sugar stayed at the bottom and only half of it dissolved. So I shook up the jars while still hot and put them back in the pressure canner for another hour. That worked okay but still wasn't as nice as the first batch. I don't remember which was darker.