not that simple, unfortunately - hops and barley engravings were around for a very long time and adorned a variety of glass shapes - from very rare instances of Lynn tumblers c. 1760's (see the Delomosne catalogue for the Wilmot collection) - the more common dwarf ale of the second half C18/early C19 (see Ronald Gabriel's 'English Drinking Glasses') - and on through to late C19 copies of Georgian rummers (see Stephen Parry's 'DWARF ALE GLASSES and their Victorian Successors').
The quality of engraving of h. & b. can be variable too - this one is perhaps not that good.
On its own the unpolished pontil scar is unreliable - these can be found from the C18 well into the C19.
Tumbler shapes can be diverse - barrels, waisted, tapering/slightly tapering sides, almost parallel sided, and seems many of these shapes overlap in date - no doubt for the usual reason that regional progression of styles/fashion lacked a common rate of advance. Those examples with disproportionate height to width are quoted as being specifically from c. 1825 - 30.
Quoting from John A. Brooks 'Glass Tumblers 1700 - 1900' regarding shape, he says..........
"".............most tumblers of the C18 conform to a consistently plain pattern with parallel or slightly tapering sides, a flat base between a quarter and half inch thick and the greater majority with a pontil mark. The average height is four inches and the consistency of size and style during most of the century is because they were all hand made""
It's sometimes easier to date better quality pieces due to the appearance of specific engraved subjects or particular decorative features such as blazes - but of no use here.
To my eyes this looks perhaps just a little too tall for its width to be as early as you've suggested, so my own opinion might be somewhere around
1790 - 1815, but you can see how complex it can be dating these things and not really my area, and we lack a good dedicated book to help. Neil used to do these things - perhaps he might look in.