If you see a sign saying "non potable" or "not drinking water" on a tap, fountain or spring then don't drink the water. But tap water in the UK is perfectly safe and it is quite usual to order a jug of it in a restaurant (although mineral water will be available in all but the cheapest of places). There will seldom be a charge for tap water.
The growth of English vineyards has been very significant in the past 20 years and if you look at our Essex Map page you will see a fair number of small ones to visit on your tour. The link to English Wines provides more information. Some of these wines are quite good and some English Methode Champenoise wines are considered world class (although few Frenchmen would agree). Pinot Noir and Chardonnay can be found but you are more likely to find grapes such as Chasselas, Madeleine Angevine and Bacchus that suit the cool climate.
There is a big advantage to being a country with a poor reputation for its own wines, and that is that the market for imported wines is very well developed. If a wine is exported from its home country, the chances are you will find it available for sale in England. Wine on restaurant lists and for sale in wine shops tends towards a global mix but expect a high mark-up in restaurants. Wine by the glass is often available in bars as well as restaurants, but the choice is seldom great. Pubs, with a few notable exceptions, do not have a good reputation as places for oenophiles, in many the choice will be limited to red, dry white or semi-sweet white.
While beer is part of English culture, nowadays the most popular drinks are mass-produced, keg bitter and lager from the usual international brewing brands. This monotone is lightened by foreign and pretend-foreign beers in the larger pub chains. Fortunately, this depressing collapse of what was once a vibrant industry was foreseen by the British CAMRA organisation which works to promote real ales. If you want to get hold of these better beers then look out for a CAMRA sign on the outside of pubs. There will also generally be a better choice of beers in a "Free House", meaning one that is not tied to a brewery and so can serve whatever the publican wants. If in doubt, ask the bar staff to tell you what they have and then try a "half" (half a pint) until you find which brews you like.
The following breweries exist in the area:
The number of British pubs is reducing every week, but the institution still acts as a social centre for many people, particularly in rural communities where there may be few alternatives. Note that some English people connect drinking beer with drunkenness and violence. If you find yourself in a pub or outside a pub where clearly people are the worse for wear, it is wise to walk away. A drunk man seldom feels any pain but a sober man does!
A pub does not normally provide table service although some pubs have restaurant areas where the bar staff will serve you (although it is still usually necessary to order both food and drink at the bar, then site down). If you want to sit down and drink rather than propping up the bar, then send most of your party to an empty table while you go to the bar. The people there will constitute a queue even if you cannot see it. The barman/maid can see the "invisible queue" and it will be fairly managed so wait until he or she catches your eye. Order your drinks (for the whole party - it is not done for each person to order or pay for their own) and, when you are told what to pay, pay there and then. Take care that the barman puts the change in your hand or else it will end up in a puddle of old beer and hence soggily to your pocket. Pick up your drinks and take them to your table. When you are ready for a refill, send someone else to the bar with the empty glasses and repeat until the evening is over.