I've been playing around with these quite a bit.
Here's a list of my best tips:
It really helps to mix everything up and THEN preheat your waffle maker.
Only use 2 oz (1/4 cup) water or other allowed liquid.
Use a wire whip/whisk to mix ingredients (except packet) and make your egg slightly foamy, then add packet slowly as you whisk.
Keep the baking powder under 1/8 tsp. A pinch is really best.
I use a thin wooden spatula type instrument to quickly "paint" the batter on my waffle iron, then lower the top. I've found if I just plop 1/3 cup batter in the middle of each section, I get more side "blow out" of batter and more mess - as well as an underdone middle and burnt edges.
Use Pam spray before 1st waffle and between each batch.
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Don't let your waffle iron get too hot.
This steams out the water content too fast and leaves the waffle thinner, or even worse, stuck paper.
Resist the urge to thin your batter with more water. Again, extra water will steam out too fast and leave you with a mess.
Don't whip your egg too stiff. In my experiments, the stiffer egg made huge puffed oddities.
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Ingredients:
1 egg white or 1/4 cup liquid egg white product
2 oz (=1/4 cup) water
1 tsp vanilla
A pinch baking soda, not more than a slight 1/8 tsp
A pinch sea salt
A pinch to 1/4 tsp cinnamon, nutmeg, cardamom, pumpkin pie spice, etc.
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1 IP pudding packet for a sweet waffle
--*--OR--*--
1 IP soup packet for a savory waffle
Directions:
Mix all but packet with a wire whip/whisk until your egg makes up some foam. Continue whisking while you add your packet. Whisk until completely smooth. Let batter sit while you plug in waffle iron. Pam spray all grids/both sides. Use 1/4 - 1/3 cup per grid, depending on your waffle maker. Cook 3 minutes and check for doneness.
My waffle maker has an indicator light. I've found the temp perfect once that light goes off. It relights once I place the batter, and I've found it goes off again when my waffles are perfectly cooked. This cycle seems to be 3 minutes. I use a Salton 2 waffle maker I got at a thrift store for $2.50!