How can I adjust a recipe for different grades/brands/types of gelatin? I'm trying to reproducibly make a specific jelly recipe. How can I achieve consistent results, using different grades/brands/types of gelatin?

Depending on what I can find in grocers nearby, I may have gelatin granules from a variety of manufacturers, or gelatin leaves from a variety of manufacturers. The area of a gelatin leaf seems to differ from country to country (I don't have accurate enough scales to test if the weight differs). Some packs of leaf gelatin say "silver" or "gold", and some specify a "bloom".

How can I convert between these different types of gelatin? Does 10g of gelatin from one manufacturer always have the same effect as 10g of gelatin from another manufacturer?

I found one web page which gave the following formula:


1 (0.25 oz.) envelope granulated gelatin = 1 tablespoon powdered gelatin = 3 sheets leaf gelatin


but the trouble with an unattributed formula like this is that I have no idea if it works across countries / brands. (Is the formula the same in metric countries?) I'm looking for a verifiable standards-based answer. Answers of the form "My great-aunt Maude always said that two farthings-worth of fancy leaf gelatin were the same as two rounded muckles of powdered, and she lived to be 102" will be down-voted.
Looked up 'gelatin strength' in Google and found this link. Very interesting.

There are two types of gelatin: A and B (I have no idea what the 'isoionic point' is).

Anyway, in the shop, I guess you'll find approximately the same 'strength' gelatin, independent of the format.

Normally, the gelatin sheets are 2g and the granular gelatin is packed in 6gr envelopes. 3*2=6.

6g of gelatin (1 envelope) will bind 500ml water for jelly (as per the instructions on the envelope). Substitute water for other liquid and you are set to go.

Edit: Personally, I don't think the precision is too important. This weekend I added too much water to a recipe (500ml) and the result was nearly perfect. That is, it didn't collapse but was hard to ration.

Also - Changed gr to g.