How do I deal with a really wet, messy dough?

For very high hydration loaves, you want to create your gluten development without adding an excess of flour which would reduce the relative hydration.

This video from Italyum Recipes shows the classic stretch, slap and fold method, using a 70% hydration dough. Basically, you lift the entire dough from the work surface, allow it to stretch under its own weight, then slam it down again. Rinse and repeat.

A somewhat less labor instensive method is described at The Fresh Loaf (the article has a lot of introductory material, keep reading and there are really clear instructions with lots of photos):

1. Initially stir the dough together until it is is a thick and cohesive liquid, which the author describes as "like porridge."

2. Use the stretch and fold method of kneading to create some development:

   • Flour your work surface moderately
   • Pour the dough out onto the surface
   • Use your bench knife knife (also called a dough scraper) to lift and drop the dough back on itself, stretching it. See this image from the Fresh Loaf:

   

3. Allow the dough to rest and autolyse, that is, develop gluten from the reaction of the water and precursor proteins in the presence of enzymes naturally in the flour. This limits the amount of hand kneading you have to do.

4. Repeat the stretch and fold method a couple of times to get the final development

Finally, note that very wet doughs can also be kneaded entirely in a stand mixer simply by beating them for a couple of minutes. These doughs are wet enough to be nearly pourable, and do not climb and clump onto the paddle; if they do, the hydration is not high enough for this method, and you need to use the dough hook instead.

One thing that will often help is to allow the dough to rest for a while (15 minutes or longer) after mixing and before kneading (cover the dough with plasic wrap). That resting period starts autolysis, the actual absorption of the water by the flour and the beginning of gluten development. That will make the dough less sticky and easier to work with without adding flour, which as you say, can throw off the hydration of the dough if you use too much. Your concerns about using too much flour to keep the dough from sticking while kneading are well founded.

I attended the Hearth Bread baking coarse at the Culinary institute of America California campus.

One of the exercises we did was designed to teach us about gluten formation. In the morning We made a very high hydration dough, a very wet ciabatta. First we autolysed the dough for around 30 minutes. We then added the salt and mixed very shortly, just enough to incorporate all the flour and water. We then placed the dough in lightly oiled rectangle tubs and covered.

Over the coarse of the rest of the day we turned the dough at regular time intervals. We would wet our hands and fold each side into the middle so that each of the four sides was folded into the center and then we would turn the dough over, cover and repeat at the next prescribed time.

It was clear at each folding there was an increase of gluten formation since the previous folding. At the end of the day we had a dough that had sufficient gluten formation and we formed into loaves proofed over night and baked.

The high hydration was to demonstrate the principle with a difficult dough but it applies to any bread dough.

This was essentially the slap and pull method stretched ( pun intended ) out over the coarse of a day.

Besides what SAJ said, three more points: start with cold water (use ice cold if you have it) and add a little bit of vitamin C. Also, don't forget the salt. But don't reconsitute yeast in cold water. If you are using instant dry, first make a sponge with some room temperature water, then add the remaining amount of water as icy cold. You can use all cold if you are using live yeast.

All other things equal, these three factors will give you stronger, tighter gluten quicker. It will make work with the dough easier until it starts coming together.

Another option is to simply accept that it's very wet and sticky sticky. Instead of dabbing your hands with flour to keep them dry, rinse them in water to keep them wet!

There is a lot of technique to it, you can flour your hands and using a bench or dough scraper that you can also flour helps.

It won't be possible to knead it as you do with a regular bread or it will hopelessly stick to everything. My sourdough recipe calls for 75-80% hydration and so is very wet and sticky. After a few series of "stretch and fold" it usually gets to the point that you can at least handle it.

In this video the guy makes bread with 100%, 110% and 120% hydration. Talk about a sticky dough! It's interesting to watch his technique as he seems to handle the sticky blobs of dough.