Why Your Pizza Crust has a Gum Line (Raw, Doughy Layer Under the Sauce) [Causes & Solutions]
A gum line is a thin layer of unbaked, raw dough found directly beneath the sauce, resulting in a ‘gummy’ texture that ruins an otherwise perfect crust. This page details the exact causes and provides actionable solutions for eliminating the gum line and achieving a perfectly baked pizza throughout
This page is part of PizzaBlab’s Pizza Making Troubleshooting Guide. It provides a practical overview of the most common causes for this problem, each with a brief explanation, actionable solution, and links to related articles for deeper understanding.
The sections are listed from most to least likely, meaning the first cause typically represents the most common reason for this issue, with likelihood decreasing as you move down the list. That said, several causes can often overlap or share similar likelihoods – it’s ultimately up to your process to identify which factors are at play.
Cause 1: The Dough Was Under-Fermented When Baked
Explanation:
In an under-fermented dough, insufficient CO₂ is produced by the yeast during fermentation, resulting in a dense structure. CO₂ in the dough acts as an “insulating layer”, allowing heat to distribute evenly and bake the dough properly throughout. If the dough is too dense and lacks these air pockets, heat passes directly through the dough, concentrating on the top and bottom (cheese, sauce, and bottom of the pizza), which causes uneven baking and leaves an undercooked layer (“gum line”) in the middle.
Solution:
Use the dough at its optimal fermentation point and avoid baking dough that hasn’t fermented enough (see: The Dough Ferments Too Slowly or Not at All (Under-Fermentation)).
Read More:
- How to Tell if the Dough is Ready for Baking: 4 Dough Fermentation Tests
- How Oven Spring Affects Baking And Browning
Cause 2: The Sauce Is Too Thin and Watery
Explanation:
If the sauce is too thin and watery, it can moisten the dough excessively, preventing it from baking evenly throughout.
Solution:
Use a thicker, less watery sauce.
Read More:
Cause 3: The Sauce Sat on the Pizza Too Long Before Baking
Explanation:
Sauce that remains on the dough for too long before baking can make the dough soggy, preventing it from baking evenly.
Solution:
Work quickly and avoid letting the sauce sit on the dough for extended periods, especially when using a thin sauce or a thin pizza base.
Additional Notes / Information
In cases where the sauce may be causing the dough to become soggy and create a gum line, you can brush a very thin layer of oil (any type) on the pizza base before adding the sauce.
The oil acts as a barrier between the sauce and the dough (since oil is hydrophobic, it repels water) – thereby preventing sogginess. The layer should be just enough to create a slight sheen over the entire surface of the pizza base.
Don’t confuse a gum line with melted or solidified cheese, which can look similar. A gum line appears gray-ish, sits between the sauce layer and the dough, and is fully integrated with the dough (cannot be easily separated). In contrast, a cheese layer is yellowish-white (depending on the cheese used) and can usually be separated from the dough by scraping or gently manipulating it with your finger.
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