Bubble hash, also called ice-water hash, is a concentrate made by separating cannabis resin glands using cold water, agitation and filtration. The collected material is then dried. It can be a finished hash product or the input used to make hash rosin.
“Bubble” doesn't mean every batch fully melts, and it doesn't tell you whether the cannabis was fresh-frozen or dried before separation. Ask about each separately.
What the water and screens do
In this process, water helps carry separated material through a series of screens rather than dissolving the desired compounds in a hydrocarbon solvent. Different mesh sizes collect different fractions. Lowtemp's process comparison describes the separation and its distinction from pressing rosin. It also lists the possible inputs as fresh-frozen, frozen, or dried and cured buds or trim, which is why the word “bubble” can't answer the fresh-frozen question for you.
A screen's micron rating describes its openings. It is not a THC percentage or an automatic grade. The material collected from a particular fraction can vary by cultivar and batch, so “90 micron” should not be read as a universal promise of top quality.
Bubble hash is not automatically full melt
Full melt describes melt behavior and very little remaining solid material, using an informal quality vocabulary. Some bubble hash meets a producer's full-melt standard; other bubble hash is intended for a different use. A category name and a grade should not be collapsed into one.
The hash-grading guide explains the limits of star ratings. A six-star claim is not a laboratory certificate, and a photograph of pale hash cannot validate it.
How it differs from hash rosin
Bubble hash retains the separated resin-gland material. Hash rosin is the result of pressing hash with heat and pressure. A producer can sell one batch as hash and press another into rosin, but the finished products are not interchangeable labels.
They don't behave alike in the jar, either. Lowtemp describes bubble hash as grainy while kept frozen and tacky once it partly melts at room temperature, while rosin can be cured or worked into badder, jam, sauce and other textures. Two jars from the same wash can therefore be very different purchases.
The Wooksauce OGZ × Giraffe Puzzy review records one finished jar: freeze-dried bubble hash, $65 for a gram, greasy and unstable rather than holding its shape, and one the reviewer would buy again. The category name alone wouldn't have told you any of that, and neither the name nor the review establishes a full-melt or six-star grade.
Storage starts after proper drying
Purchased finished bubble hash and freshly collected wet hash are different states. A refrigerator or freezer is not a substitute for completing a controlled drying process.
For finished retail hash, follow the producer's storage directions and keep cold containers sealed while they warm before opening. Storing bubble hash covers that distinction. Keep the batch label with the container so a change or complaint can be traced to the actual product.