I am trying to make a 10X recipe of a cooked pudding. It uses flour and corn starch as a thickener. I scaled up the ingredients proportionally, but it is not as thick. Any recommendations on how better to scale the ingredients? Is the sugar interfering with the gel? Do I need to change the ratio of the thickeners? Should the proportions be different? Any thoughts?
Scaling out a recipe is often more difficult than just "multiplying" the ingredients. In the Book Ratio they have a chapter on Custard:
The standard ratio is bedrock, 2 to 1; 16 ounces milk blended with 8 ounces (4 large) eggs will result in 24 ounces of an excellent custard. Large eggs are about 2 ounces each, which makes custards easy to manage without a recipe: a cup of milk and 2 eggs, or ½ cup of milk and 1 egg. But 1 large egg will set three-quarters of a cup of milk into a perfect custard. So, as with all ratios, and recipes, it can vary. If you intend to turn the custard out and it needs to hold its shape, stick with the basic ratio. Extra yolks are often added for texture and richness. The quantity of sugar and the quantity of fat also affect the final outcome. If you’re using a lot of sugar, you may need to add a little more protein for structure. If you’re using only heavy cream, you may need less.
Ruhlman, Michael. Ratio (Kindle Locations 3475-3481). Simon & Schuster, Inc.. Kindle Edition.
Simply doubling a recipe is usually pretty straight forward...the more you scale upwards the more 'out of alignment' your ratios become (particularly where eggs are involved).
Without your base recipe I have to warn 'your mileage' may vary' So be prepared to tweak it to your taste.