Agar Powder GS800 vs GS900 vs GS1000: How to Choose

By Anggit Dimas Anggoro, Director of Sales and Marketing, PT Bospres Global Resources

Choose GS800 if you need a reliable general-purpose agar, GS900 if you want a firmer gel with the same handling, and GS1000 when texture is the priority. The number is the gel strength in g/cm², so the real question is how firm a gel you need and how much agar you want to use to get it.

This guide compares the three grades we supply from Indonesia, explains how gel strength is measured, and shows what stays the same between grades. All numbers come from our product datasheets.

What does gel strength mean for agar powder?

Gel strength is the force a standard agar gel can bear before it breaks, expressed in g/cm². A higher number means a firmer gel at the same concentration. It also means you can use less agar to reach the same firmness, which matters when you buy by the tonne.

Our agar gel strength is measured by the GS Japan method, using a 1.5% gel at 20 °C. Always compare gel strength figures that use the same method and concentration, because a number from another method is not directly comparable.

How do GS800, GS900 and GS1000 compare?

The three grades differ only in gel strength. Every other specification in the catalogue is the same.

Because the melting and setting points are identical, the three grades behave the same way in the kitchen or the plant. Agar dissolves near boiling, then sets as it cools to around 36–38 °C. Switching grade does not change your heating and cooling profile.

Which agar grade is right for my application?

Gel strength is a starting point, not a rule. Test each grade in your own recipe. As a guide:

• Desserts and jellies: start with GS800 for a soft, sliceable set, and move up if you want a firmer bite.
• Confectionery: GS900 or GS1000 gives a firmer, more stable structure.
• Technical uses and microbiological media: higher grades are often preferred for strong, clear gels.

If you are unsure, ask for free samples of two neighbouring grades and run them side by side at the same concentration.

Is a higher gel strength always better?

No. A higher grade gives a firmer gel, but a recipe that needs a soft, tender texture may not benefit from it. The practical advantage of a higher grade is efficiency: you may need less powder for the same firmness. Compare cost per finished kilogram, not just price per kilogram of agar.

How do I test agar grades fairly in my own recipe?

A fair trial changes one thing at a time. Use the same water, the same agar concentration, the same heating time and the same cooling conditions, and change only the grade. Then compare the results after the gel has fully set.

1. Weigh accurately. Small differences in agar concentration change the firmness more than a 100 g/cm² step in grade.
2. Disperse before heating. Mix the powder with sugar or cold water first, so it does not clump when it meets hot liquid.
3. Heat until fully dissolved. Agar needs a temperature close to boiling (its melting point is 84–86 °C) to dissolve completely.
4. Cool and rest. The gel sets at 36.5–38.5 °C, but give it time before you judge the texture.
5. Judge texture and clarity. Check firmness, cut surface and syneresis (water release) after a day in storage.

Record the result in a short table, then repeat once with a second lot. A grade that works well in two lots is a safer choice for production.

What mistakes do buyers make when comparing agar grades?

The most common mistake is comparing gel strength numbers from different methods or concentrations. A figure measured on a 1.0% gel is not the same as one measured on a 1.5% gel. Ask every supplier which method and concentration they use.

The second mistake is buying on gel strength alone. Also compare clarity, color, particle size and the microbiological limits below, because these decide how the agar behaves in your process and whether it passes your own incoming checks.

The third is assuming the grade on the label is the grade in the bag. Ask for the certificate of analysis for the specific lot and compare it with your own acceptance range.

What quality checks come with each lot?

Each lot ships with a certificate of analysis. Besides gel strength, our agar specification covers purity and safety limits:

• Total ash max 5%, acid-insoluble matter max 1%
• Starch and gelatin/protein: negative
• Lead max 5 mg/kg, cadmium max 1 mg/kg, mercury max 0.5 mg/kg, arsenic max 3 mg/kg
• Total plate count max 3,000 cfu/g, E. coli negative in 5 g, yeast and mold max 150 cfu/g, Salmonella negative in 5 g

Our datasheets are available as PDF on request.

What should I know about supply and ordering?

• Minimum order: 550 kg (1 CBM), packed in 25 kg bags.
• Lead time: 14 days after deposit.
• Shipping: CIF, FOB or other Incoterms by agreement, from Tanjung Priok or Tanjung Perak.
• Samples: free, with shipping paid by the buyer. Sample size can be adjusted to your request.
• Availability: GS800, GS900 and GS1000 are all available.

Gel strength can vary slightly with the quality of incoming seaweed, which is why we confirm the actual figure on the certificate of analysis before shipment.

Where can I see each grade?

See the full specification, supply details and FAQ on the pages for Agar Powder GS800, Agar Powder GS900 and Agar Powder GS1000, or browse the whole agar powder range.

Not sure which grade fits your recipe? Contact our team with your application and target texture, and we will recommend a grade and send a free sample.

About the author: Anggit Dimas Anggoro is the Director of Sales and Marketing of PT Bospres Global Resources, which supplies agar, carrageenan and dried seaweed from Indonesia under the Bospres Hydrocolloids brand. He works directly with buyers on specifications, samples and export documents.