Bittersweet · 1 trees planted · confidence high
The true English variety is a hard-tannin Devon bittersweet, yellow flushed and lightly striped red, with sweet-astringent flesh; Long Ashton lists it at 0.27% malic acid and 0.34% tannin, high enough to carry a medium-dry cider close to single-varietal. It crops well but is strongly biennial. Before relying on any of this, confirm which variety you actually have — the fields above describe the English original, but if these trees came from a US nursery they are most likely the mis-catalogued Geneva clone, which behaves as a sharp, not a bittersweet.
Disease: Frost resistant and generally hardy; no scab or fireblight ratings published by WSU or Long Ashton. WSU rated the Geneva material 2.0 for blind wood, indicating a meaningful tendency to bare branch sections that affects pruning.
Discrepancies: This is the most serious discrepancy in the set and it is an identity problem, not a measurement problem. WSU Mount Vernon lists the cultivar as Tremlett's (Geneva) and annotates it explicitly: Not the true Tremlett's Bitter. WSU classifies it as SHARP — tannin 0.17%, malic acid 1.01%, pH 3.17, SG 1.044, 10.9 Brix, harvest 9/30, bloom 5/5, alternate bearing yes, productivity only 2.8/5. Long Ashton's true English Tremlett's Bitter is a BITTERSWEET at 0.34% tannin and 0.27% acid. These are opposite ends of the classification system: roughly four times the acid and half the tannin. The cause is a mis-catalogued tree at the USDA Geneva, NY repository from which most US nurseries propagated. Recommendation: if these trees were bought from a North American nursery, assume the Geneva clone and use the WSU numbers — a low-sugar, very high-acid sharp that will acidify a blend rather than add tannin, and a weak cropper at 2.8/5 productivity. The cider_type, acidity, tannin and SG fields above describe the English original as requested by the variety name, but they are probably wrong for the actual trees. Resolve by measuring juice pH at harvest: below about 3.3 confirms the Geneva clone, above about 4.0 confirms the true bittersweet.