|18th century port bottles: Source|
In 1831, The American Quarterly Review printed, amongst other articles, an extract from the Reverend George Croly's Life and Times of His Late Majesty, George the Fourth: With Anecdotes of Distinguished Persons of the last Fifty Years (1830).
In one part of the work, Reverend Croly asserts that Pitt was merely a public man, and almost apologises for Pitt's addiction to alcohol:
"Pitt's life was in the Senate; his true place of existence was on the benches of that ministry which he conducted with such unparalleled ability and success. He was, in the fullest sense of the phrase, a public man, and his indulgences in the few hours which he could spare from the business of office were more like the necessary restoratives of a frame already shattered than the easy gratifications of a man of society: and on this principle we can safely account for the common charge of Pitt's propensity to wine. He found it essential to relieve a mind and body exhausted by the perpetual pressure of affairs: wine was his medicine, and it was drunk in total solitude, or with a few friends from whom the minister had no concealment. Over his wine the speeches for the night were often concerted, and when the dinner was done, the table council broke up only to finish the night in the house [of Commons]. 
It is clear to anyone interested in the life of William Pitt that Croly did not personally know him. It is agreed that Pitt's life was dedicated to the service of his country, but he did enjoy the company of his friends, and he reveled in the fleeting moments of respite he could spare from business. It is difficult to tease out the private life of a man whose existence was so exclusively political, but there is enough surviving evidence to suggest that Pitt enjoyed his personal life. He travelled to his villa at Holwood as often as he could, and he "often gave, and often accepted, small dinner parties, and took great pleasure in them." 
In 1823, many years after the death of Pitt, Lord Grenville (a cousin and political associate) reflected upon Pitt's overuse of wine: "Dr. Addington [Lord Chatham's physician] ruined his [Pitt's] health. Port wine was Addington's great remedy, and at Hayes [Pitt's childhood home] I used to wonder at the bumpers they were drinking, confined as I was to water. Afterwards it became necessary to him [Pitt]; and though never more affected by it than others in general, he certainly drank freely." 
On one of his visits to Holwood, the landscape architect Humphry Repton remembered that there was "a degree of cheerfulness and lightness in his [Pitt’s] manner which no one could suppose from his natural formality and stateliness of person."  Repton also recalled staying overnight at Holwood after a late visit to the property in the summer of 1794. Repton was passing through Kent, and he came to Holwood one evening when Pitt was there with a large party dining with him. Repton was requested by the servants to alight, and Pitt came to him immediately. Repton recollected that Pitt assured him, 'Mr Repton never think that a visit from you at Holwood can be any intrusion since I always come here to enjoy that sort of pleasure to which no man can contribute so much as yourself.'"  So much for the unfeeling statesman living only for public life!
Repton continued: "While we continued talking, coffee was brought in, and it was settled that I should remain all night, 'if I could sleep in a room like a berth on board a ship,' [this sounds like Pitt's words] which was that room usually occupied by Lord Mulgrave."  The two men then joined the large party in the dining room., and later in the evening it was proposed that they would all sally forth to see the late improvements at Holwood by moonlight. It seems there is truth about Pitt's penchant for rising late in the morning. Repton remembered, "next morning we were out before 8 o’clock, and his [Pitt's] friends ridiculed his attempt at early rising as he seldom was up so soon (tho’ always in time to be at the Treasury by 11)." 
Another direct eyewitness was Eliza Pretyman, the wife of Pitt's friend and former tutor George Pretyman (the Bishop of Lincoln). She recorded in her journal of 1801 Pitt's convivial temper, his selflessness, and his great delight in private society:
“…His own interest indeed, never in any occasion seems to occur to him. The vivacity of Mr Pitt’s disposition naturally led him to be fond of Company from Childhood; and he has ever sought relaxation from “the weighty business of the State” in the freedom of Social Converse with a set of private friends. He is extremely fond of Conversation - of lively, playful Conversation, and excels in it beyond all men. The pleasures of Conversation, and the pleasures of the Country, - not hunting & shooting, but improvements in His Grounds, reading, riding & walking…and Reading (for he read almost everything worth reading), while in Office. - At Putney, and far a long time at Holwood, after a very moderate time at dinner, Mr Pitt & each of his friends used to take a Book, or stroll out as they were inclined, till business (to which two or three hours in the Evening was always devoted) or supper summoned them; and they always retired early (about eleven) to bed." 
In this contemporary account by someone who knew him well, Pitt is depicted as being fond of company with his friends, intellectual conversation, reading, walking, horseback riding, landscape gardening, and relaxation from public life. He did occasionally shoot for sport, but Mrs. Pretyman choses to play this down.
On the subject of wine, however, Mrs. Pretyman lamented Pitt's ample consumption. Her husband, The Bishop of Lincoln, “never in his life saw Mr Pitt in the least affected by wine till the year 1798, when they were alone together one Evening at Holwood. Mr Pitt was at this time very unwell [probably June or July 1798], and in the earnestness of Conversation he filled his Glass so often as to affect his voice and manner, but not his understanding. The Bishop was excessively hurt and proposed his retiring to bed, to which he readily assented. This was the first time, but I cannot add it was the last in which the Bishop has had the poignant grief of observing similar circumstances. Alas! in other Society I fear - but I forbear. With respect to the quantity of wine which Mr Pitt has drank from early youth, which has I believe astonished many, and given rise to many false aspersions, it was prescribed for him as a medicine by Dr. Addington to drink a bottle of port wine a day when he was a boy of fourteen, and this he did do under his Tutor’s eye in the course of the day, and as a task, rather than with any wish to exceed. Mr Pitt’s constitution was remarkably delicate at an early period of life. At fourteen he weighed only six stone & two p[oun]ds [86 lbs.]. His Father, Lord Chatham, had the Gout while he was at Eton School, and the Constitutions of his Children were all thought to require a very full diet, and a great deal of port wine, and they were accordingly accustomed to this from Childhood….when motives of health originally induced the habit of drinking an unusual quantity, and till within a few years Mr Pitt had no inclination to exceed the limits of Temperance, nor did he exceed, except perhaps in Company which led him to excess. His moderation was remarked at White’s as a part of his singular character considering his uncommon vivacity…One of my authorities for these aspersions is Mr Eliot, himself a member of White’s and living much with Mr Pitt before he married his Sister as well as afterwards…” 
In October 1798, Pitt's physician Sir Walter Farquhar apparently also noticed the physical effects which the excessive quantity of wine was having on Pitt's constitution. In a letter to Pitt of the time, Farquhar prescribed "nearly a Pint of Port after [dinner], but not quite - as one is apt, by the Society of Friends and the Eagerness of Conversation upon interesting subjects to forget quantity, it would be a very proper thing to have the Pint Bottle of Port put upon the table - such a measurement of restraint would answer better..."  This advice does not appear to have been adhered to, at least not for long. By the late 1790s, Pitt's habits of excessive wine consumption were confirmed, and the unremitting pressure of business and the war with France only increased such libations.
It is impossible to determine how much this excessive consumption served to shorten Pitt's life, but it cannot be denied that it had some impact on his health. From such long habits of taking wine, encouraged by the physician of his youth, Pitt probably did view wine as a necessary stimulant or 'restorative' when exhaustion overtook him or convivial company influenced him to sit for hours at the dining table. It can only be wished, but alas in vain, that Pitt would have moderated himself in this respect. It may have protracted his life.
1. An extract of Reverend George Croly's Life and Times of His Late Majesty, George the Fourth: With Anecdotes of Distinguished Persons of the last Fifty Years (1830), printed in The American Quarterly Review, Vol. IX. (1831), p. 323.
2. Ainsworth, W.H. (ed.) (1862) The New Monthly Magazine, Vol. 125. London: Chapman and Hall, p. 341.
3. Rogers, S. (1859) Recollections, 2nd Edition. London: Longman, Green, Longman & Roberts, p. 189.
4. Humphry Repton's Memoirs. The British Library, BL Add Ms 62112.
8. Notebook by Mrs. Tomline (October - November 1801). Kent History and Library Centre, Pitt MSS: U1590/S5/C41.
10. Medical advice from Sir Walter Farquhar to Pitt, 10 October 1798. The National Archives. PRO 30/8/134.