Sesame Paste (Zhi Ma Jiang): How to Fix It When It Seizes

2026-08-31

Chinese sesame paste — 芝麻酱 — is made from toasted sesame seeds, which gives it a deeper, nuttier, slightly bitter edge than the raw-seed tahini most Western kitchens already have. It's the base of cold noodles, and the reason those noodles taste like something you'd order rather than something you threw together.

Why it seizes, and the fix

Add water to sesame paste and it stiffens into a stubborn lump that won't mix. This isn't a mistake on your part — it's how the emulsion behaves. The fix is counterintuitive: keep going.

💡 Add liquid a small splash at a time and stir hard in one direction. It will seize, then look worse, then suddenly turn smooth and pourable. The whole thing takes about two minutes. Trying to fix it by adding a lot of water at once just gives you lumps floating in water.

What to thin it with

Warm water: neutral, lets the sesame flavor lead
Sesame oil: richer, better for cold noodle sauces
Light soy sauce: seasons and thins at once

Sesame paste vs tahini

Both are ground sesame, but Chinese sesame paste uses toasted seeds and tahini usually uses raw. That makes sesame paste darker, stronger, and a little bitter. In a cold noodle sauce, tahini tastes flat by comparison.

💡 Using tahini in a pinch? Toast it lightly in a dry pan first and let it cool, or add a few drops of toasted sesame oil to push it in the right direction.

Where to use it

Cold sesame noodles — the classic, and the whole reason to own a jar
Cold dressed dishes, thinned into the dressing
Hot pot dipping sauce, mixed with furu and chili oil

Storage

Store it in the fridge once opened; the oil separates and rises, which is normal. Stir it back in thoroughly before each use. If it separates and you never stir it, the bottom layer goes hard and dry. Kept stirred and cold, it lasts several months.

💡 Scallion noodles are the fastest test of whether you thinned it correctly — the sauce should coat the noodles, not pool at the bottom of the bowl.

Recipes that use it

Once you have a jar of smooth, properly thinned paste, these are the dishes to point it at.

Wuhan hot dry noodles — the one dish where sesame paste is the sauce rather than an ingredient: thinned paste clings to hot alkaline noodles with no broth at all, so the consistency you learned above decides whether the bowl works.
Chengdu dan dan noodles — a spoonful of paste goes into the sauce base under the chili oil and minced pork, where it rounds the heat into something nuttier.
Northern-style sesame dipping sauce — the hot pot dip built entirely on loosened sesame paste, sharpened with fermented bean curd and chive flower sauce.
Cold noodle sauce — the all-purpose summer dressing, with exact ratios for thinning the paste and seasoning it.

Frequently Asked Questions

Why does my sesame paste get hard when I add water?

It's the emulsion forming. Keep adding liquid a splash at a time and stirring in one direction — it goes lumpy, then suddenly smooth.

Can I use tahini instead of Chinese sesame paste?

In a pinch, yes, but tahini is made from raw sesame and tastes milder. Toast it lightly in a dry pan first, or add a little toasted sesame oil.

Should sesame paste be refrigerated?

Yes, after opening. The oil will separate and rise — that's normal. Stir it back in each time and it keeps for months.

Can I use peanut butter instead of sesame paste?

Yes, in a pinch. Use natural unsweetened peanut butter and thin it exactly the same way, a splash at a time. The texture is nearly identical, but the flavor is peanut rather than sesame, so stir in a little toasted sesame oil to pull it back in the right direction. It works well in dan dan noodles and dipping sauces; in cold sesame noodles, where sesame is the whole point, the difference is more obvious.

How long does thinned sesame sauce keep in the fridge?

Two to three days in a sealed container. Once water is mixed in, it spoils much faster than the pure paste, so only thin what you need. It will also thicken as it sits — loosen it with a splash of warm water before serving, and throw it out if it smells sour or off.

Why does my sesame paste taste bitter?

A slight bitterness is normal — Chinese sesame paste is made from toasted seeds, which always brings a bitter edge. If it tastes sharply bitter or acrid, the seeds were likely over-roasted or the oil has gone rancid: smell it, and if it's stale or paint-like, discard the jar. Mild bitterness in a finished sauce is easily balanced with a small pinch of sugar.