There have been some questions regarding how vigorous fermentation or bubbles affect the Brewometer's readings. The graph below shows the fermentation from an IPA. The Y axis shows specific gravity and the X axis shows time. You can see a brief period (circled in red) with a bump in the specific gravity during active fermentation. Bubbles during fermentation may alter the pitch of the Brewometer creating variances in readings. The specific gravity readings will return to being accurate as the bubbles shed from the device.