A clever way of avoiding watery slaw.
Cole slaw from Marilynn’s Place, Shreveport, Louisiana. By Shreveport-Bossier: Louisiana’s Other Side, on Flickr
The reason why cut cabbage wilts in a cole slaw has to do with the way in which water with dissolved solids (a solution) moves through plant cells.
There are three kinds of solutions: ones that have more dissolved solids than the cells (hypertonic), ones that have the same number of dissolved solids (isotonic), and ones that have fewer dissolved solids (hypotonic).
Solution always wants to reach equilibrium. For example, if you have a simple syrup and you pour it into a jug of tea to make sweet tea, then leave it overnight in the fridge, the first cup of tea won’t be any more or less sweet than the last cup of tea. The sugar will diffuse into the tea.
So if you have a standard coleslaw, and you mix the cut cabbage with a seasoned mayonnaise, the number of dissolved solids in the mayonnaise is higher than the dissolved solids in the cabbage. The water rushes out of the plant cells trying to reach equilibrium, leaving you with sort-of crisp cabbage in a runny, watery mayonnaise.
Salting and draining the zucchini before making Yesterdish’s zucchini patties
One way of dealing with this is to sprinkle salt or sugar on the vegetables in advance, which we did with Yesterdish’s zucchini patties when we didn’t want the water to weep into the hot oil.
If you cut a fruit or a vegetable and release some of its juices, then cover it in sugar, the juices and sugar will mix into an extremely hypertonic solution right outside the plant cell walls. The water trapped in the cells will start to flow through the plasma membrane and out of the cell wall, trying to reach equilibrium with the sugar.
In plants, the plasma membrane on the inside of the cell wall shrivels inward, but the cell wall remains strong. The result is a crisp vegetable that doesn’t weep into your mayonnaise. (Let’s just leave an in-depth discussion of animal cells to another time–the short version is that they lack cell walls, but the process of brining works because of disruptions to the helix structure of the proteins themselves, something we talked about a bit in the post for bar-b-q’d brisket.)
But that requires salting, rinsing and draining the salad in advance. What recipes like this one do is to factor the water from the cabbage and the sugar used to draw out the water into the recipe for the vinegar-based dressing itself. Here’s a version from the June 13, 1961 edition of the Hutchinson (Kansas) News:
24-Hour Cole slaw
1 c. white vinegar
Combine vinegar, salt, celery seed, mustard, pepper and salad oil. Boil mixture for three minutes and add to mixture of cabbage, onion, green pepper, olives and sugar. Cover, cool and let stand in refrigerator 24 hours. Stir occasionally.
Mrs. Helen Kindsvater
From the box of F.J. from Sun City, Arizona. Some cards suggest a family history in Missouri and Kansas.
1 medium head of cabbage, chopped
2 medium onions, sliced
3/4 cup sugar
1/4 cup green pepper (optional)
Arrange in layers in a gallon bowl.
1 tsp. sugar
1 tsp. celery seed
1 tsp. prepared mustard
1-1/2 tsp. salt
1 cup vinegar
Bring to a boil. Add 1 cup of salad oil and bring to a boil again. Pour over cabbage mixture. Cover and refrigerate and use in 24 hours. Will keep in refrigerator 5-6 days.