Homemade Belgian Candi Syrup Nutrient question

[stpug]

I've recently made some belgian candi syrup using a thread on this site which calls for the use of yeast nutrient (diammonium phosphate) during the processing of the sugar. My question is: Does that nutrient remain in the syrup upon completion or does the chemical reaction that takes place between the sugar and nutrient drive it off? During the carmelization of the sugar you are very aware of the ammonia gases coming out of the cooking pot (does this mean the nitrogen is leaving the solution?)

I've got a big belgian dark strong planned and am considering using some nutrient in the boil but will scale it back depending on whether I can count on the nutrients used in the candi syrup to still be present.

Any help is appreciated.

 

[BigRapidsBrewingCompany]

Ammonia (NH2) gases leaving the boil = nitrogen leaving. Diammonium sulfate dissolves into liquid into free NH3 (ammonium) which is necessary for the metabolism of yeasts (A.K.A. fermentation of sugar into CO2 and H20). I would suggest adding the yeast nutrient to the end of the boil (last 10 mins) to prevent loss of ammoinum. There is no reaction between sugar and DAP, only with yeast is there a reaction. Heating DAP (your yeast nutrient) destabilizes the extra hydrogen in the complex and can release it, allowing NH2 (ammonia) to be released in a gaseous form. I hope this kind of answers your question. I am not totally sure what order you're doing this process in.

-Spencer

 

[stpug]

Thank you. That helps and confirms what my nose suspected (most of the nitrogen was released in gaseous form), therefore I cannot conclude that my syrup contains much (if any) residual nitrogen. Granted, I've always understood that barley provides plenty of nitrogen for yeast in most circumstances, however in a recipe containing ~20% simple sugars might leave the reserves a little on the low side, especially for a big beer where nutrient, oxygen, pitching rates, etc are all going to matter even more.

Cheers!

 

[ajdelange]

Some of the ammonium ion (NH4+) converts to ammonia (NH3) which reacts with the sugar to form the Maillard products you are seeking when you make Candi sugar. That's why it is added - not to nourish the yeast during subsequent use of the product. And, of course, the fact that you smell ammonia (NH3) indicates that some of the ammonia is escaping. Depending on pH some of the ammonium ion will remain as ammonium ion and, presumably, survive into the finished sugar. This would serve as a yeast nutrient of course but I wouldn't rely on it as the only source if it is your intention to supplement the nitrogen found naturally in your wort. FWIW I have never used nutrient in a ferment (but always use it in starters) and have always had vigorous ferments. If you are concerned that the 20% sugar content means 20% less FAN then use a supplement.

 

[stpug]

Thanks AJ! That's a great explanation of what's happening to the FAN during the making of candi syrup/sugar. I have never used a yeast nutrient in a beer except for this particular dark strong due to the high sugar content, high gravity, and the fact that I'm using revived, stepped-up, frozen, bottle harvested yeast .

This beer had about a 24 hour lag phase after pitching. However, it has since been ticking along at a slow and deliberate pace just "like a monk" . The krausen has been creeping it's way towards the top of the bucket over the past 3-4 days. I started with 3.5 inches of headspace and it's dwindled to about 1.5. Now, I'm just crossing my fingers that they'll bring the beer down to a decent FG (1.015ish).