Summit was released in 2003 by John I. Haas, developed as a very high-alpha American hop at a time when the double IPA and imperial IPA categories were creating real demand for bittering hops that could deliver serious IBU from a manageable weight. What sets Summit apart from other high-alpha releases of the same era isn't just its alpha acid — among the highest of any commonly available hop — but a genuinely unusual aroma note that shows up when it's used fresh: a distinct onion-and-garlic character alongside its tangerine and grapefruit.
Near the top of the alpha range for any hop
At 16-19% alpha acid, Summit sits near the top of the alpha range for any hop on this site, which makes it extremely efficient as a bittering charge — a small weight covers a large share of a big beer's bitterness target. Despite that bittering strength, Summit is also genuinely used for aroma and dry-hop purposes in some recipes, specifically for the tangerine and grapefruit notes that come through in cooler, less prolonged contact with the beer.
Aroma character — and its most talked-about quirk
Tangerine and grapefruit form Summit's citrus backbone, but the variety is best known among brewers for a distinctive fresh onion-and-garlic note that shows up prominently when hops are handled or dry-hopped while very fresh, and which tends to mellow and largely disappear with time, oxidation, and especially with a proper boil. This isn't a defect or a sign of poor storage — it's an inherent characteristic of the variety's oil profile, most noticeable in whirlpool and dry-hop use with very fresh hops, and brewers who work with Summit regularly generally know to expect and plan around it rather than treat it as a spoiled batch.
Bittering first, aroma once the onion fades
Double IPA and imperial IPA are Summit's primary home, almost always for its bittering efficiency, with some brewers also using a portion of the charge late in the boil or dry hop specifically for the tangerine-grapefruit character once they've learned to manage the onion-garlic note through timing and blending with other hops. It's less commonly used as a beer's sole hop given how polarizing that fresh onion character can be to an unprepared palate.
Substitutes
Simcoe is the closer substitute for Summit's pine-and-citrus-adjacent role in a recipe, though at meaningfully lower alpha acid, meaning a larger weight is needed to match Summit's bittering output. Chinook is the second substitute, sharing some of Summit's resinous intensity without the onion-garlic quirk, though also at lower alpha acid.
A hop that rewards understanding its quirks
At Summit's alpha range, even a small weight change moves the calculated numbers meaningfully, so a planned bittering charge is worth running through the IBU calculator first. Brewers new to Summit sometimes react to the onion-garlic note as though something has gone wrong, when in fact it's simply the variety behaving as it always does when used young and fresh in whirlpool or dry-hop additions. Blending it with a second, more conventionally fruity hop, using it primarily for early bittering rather than a heavy dry hop, or allowing a dry-hopped beer additional conditioning time before packaging are all common ways brewers manage that character rather than avoid the variety altogether — a beer that tastes distractingly of onion at kegging can settle into something closer to grapefruit and tangerine after a couple of weeks of cold conditioning.